1
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Riesner M, Shabani F, Zeylmans van Emmichoven L, Klein J, Delikanli S, Fainblat R, Demir HV, Bacher G. Demystifying Trion Emission in CdSe Nanoplatelets. ACS NANO 2024; 18:24523-24531. [PMID: 39159423 DOI: 10.1021/acsnano.4c08776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/21/2024]
Abstract
At cryogenic temperatures, the photoluminescence spectrum of CdSe nanoplatelets (NPLs) usually consists of multiple emission lines, the origin of which is still under debate. While there seems to be consensus that both neutral excitons and trions contribute to the NPL emission, the prominent role of trions is rather puzzling. In this work, we demonstrate that Förster resonant energy transfer in stacks of NPLs combined with hole trap states in specific NPLs within the stack trigger trion formation, while single NPL spectra are dominated by neutral excitonic emission. This interpretation is verified by implementing copper (Cu+) dopants into the lattice as intentional hole traps. Trion emission gets strongly enhanced, and due to the large amount of hole trapping Cu+ states in each single NPL, trion formation does not necessarily require stacking of NPLs. Thus, the ratio between trion and neutral exciton emission can be controlled by either changing the amount of stacked NPLs during sample preparation or implementing copper dopants into the lattice which act as additional hole traps.
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Affiliation(s)
- Maurizio Riesner
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Duisburg 47057, Germany
| | - Farzan Shabani
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology and National Nanotechnology Research Center, Bilkent University, Ankara 06800, Turkey
| | | | - Julian Klein
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Duisburg 47057, Germany
| | - Savas Delikanli
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology and National Nanotechnology Research Center, Bilkent University, Ankara 06800, Turkey
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Materials Sciences, School of Materials Science and Nanotechnology, Nanyang Technological University, Singapore 639798, Singapore
| | - Rachel Fainblat
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Duisburg 47057, Germany
| | - Hilmi Volkan Demir
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM-Institute of Materials Science and Nanotechnology and National Nanotechnology Research Center, Bilkent University, Ankara 06800, Turkey
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Materials Sciences, School of Materials Science and Nanotechnology, Nanyang Technological University, Singapore 639798, Singapore
| | - Gerd Bacher
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Duisburg 47057, Germany
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2
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Climente JI, Movilla JL, Planelles J. Electronic Structure of Biexcitons in Metal Halide Perovskite Nanoplatelets. J Phys Chem Lett 2024; 15:7379-7386. [PMID: 38995267 DOI: 10.1021/acs.jpclett.4c01719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024]
Abstract
A theoretical description of biexcitons in metal halide perovskite nanoplatelets is presented. The description is based on a variational effective mass model, including polaronic effects by means of a Haken potential. The strong quantum and dielectric confinements are shown to squeeze the biexciton under the polaronic radius, which greatly enhances Coulomb attractions and (to a lesser extent) repulsions. This explains the need for effective dielectric constants approaching the high-frequency limit in previous simulations, and the binding energies exceeding 40 meV observed in single-monolayer nanoplatelets. Biexcitons are formed by a pair of weakly interacting excitons, with a roughly rectangular geometry. This translates into a constant ratio between biexciton and exciton binding energies (2D Haynes rule) well below the ideal value of ΔBX/ΔX = 0.228 proposed for squared biexcitons. The ratio is independent of the number of monolayers in the platelet, but it does depend on the lateral and dielectric confinement.
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Affiliation(s)
- Juan I Climente
- Departament de Química Física i Analítica, Universitat Jaume I, E-12080, Castelló de la Plana, Spain
| | - José L Movilla
- Dept. d'Educació i Didàctiques Específiques, Universitat Jaume I, 12080, Castelló, Spain
| | - Josep Planelles
- Departament de Química Física i Analítica, Universitat Jaume I, E-12080, Castelló de la Plana, Spain
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3
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Gungor K, Erdem O, Guzelturk B, Unal E, Jun S, Jang E, Demir HV. Strongly polarized color conversion of isotropic colloidal quantum dots coupled to fano resonances. NANOSCALE HORIZONS 2024. [PMID: 39045702 DOI: 10.1039/d4nh00101j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Colloidal quantum dots (QDs) offer high color purity essential to high-quality liquid crystal displays (LCDs), which enables unprecedented levels of color enrichment in LCD-TVs today. However, for LCDs requiring polarized backplane illumination in operation, highly polarized light generation using inherently isotropic QDs remains a fundamental challenge. Here, we show strongly polarized color conversion of isotropic QDs coupled to Fano resonances of v-grooved surfaces compatible with surface-normal LED illumination for next-generation QD-TVs. This architecture overcomes the critically oblique excitation of surface plasmon coupled emission by using v-shapes imprinted on the backlight unit (BLU). With isotropic QDs coated on the proposed v-BLU surface, we experimentally measured a far-field polarization contrast ratio of ∼10. Full electromagnetic solution shows Fano line-shape transmission in transverse magnetic polarization allowing for high transmission as an indication for forward-scattering configuration. Of these QDs coupled to the surface plasmon-polariton modes, we observed strong modifications in their emission kinetics revealed by time-resolved photoluminescence spectroscopy and via dipole orientations identified by back focal plane imaging. This collection of findings indicates conclusively that these isotropic QDs are forced to radiate in a linearly polarized state from the patterned planar surface under surface-normal excitation. For next-generation QD-TVs, the proposed polarized color-converting isotropic QDs on such v-BLUs can be deployed in bendable electronic displays.
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Affiliation(s)
- Kivanc Gungor
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM--Institute of Materials Science and Nanotechnology and the National Nanotechnology Research Center, Bilkent University, Ankara, 06800, Turkey.
| | - Onur Erdem
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM--Institute of Materials Science and Nanotechnology and the National Nanotechnology Research Center, Bilkent University, Ankara, 06800, Turkey.
| | - Burak Guzelturk
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM--Institute of Materials Science and Nanotechnology and the National Nanotechnology Research Center, Bilkent University, Ankara, 06800, Turkey.
| | - Emre Unal
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM--Institute of Materials Science and Nanotechnology and the National Nanotechnology Research Center, Bilkent University, Ankara, 06800, Turkey.
| | - Shinae Jun
- Inorganic Material Laboratory, Material Research Center, Samsung Advanced Institute of Technology, Samsung Electronics Co., 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803, South Korea
| | - Eunjoo Jang
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea
| | - Hilmi Volkan Demir
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM--Institute of Materials Science and Nanotechnology and the National Nanotechnology Research Center, Bilkent University, Ankara, 06800, Turkey.
- Luminous! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, and School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
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4
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Chang WJ, Zeng H, Terry Weatherly CK, Provazza J, Liu P, Weiss EA, Stern NP, Tempelaar R. Dark State Concentration Dependent Emission and Dynamics of CdSe Nanoplatelet Exciton-Polaritons. ACS NANO 2024. [PMID: 39042269 DOI: 10.1021/acsnano.4c03545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
The recent surge of interest in polaritons has prompted fundamental questions about the role of dark states in strong light-matter coupling phenomena. Here, we systematically vary the relative number of dark states by controlling the number of stacked CdSe nanoplatelets confined in a Fabry-Pérot cavity. We find the emission spectrum to change significantly with an increasing number of nanoplatelets, with a gradual shift of the dominant emission intensity from the lower polariton branch to a manifold of dark states. Through accompanying calculations based on a kinetic model, this shift is rationalized by an entropic trapping of excitations by the dark state manifold, while a weak dark state dispersion due to local disorder explains their nonzero emission. Our results point toward the relevance of the dark state concentration to the optical and dynamical properties of cavity-embedded quantum emitters with ramifications for Bose-Einstein condensate formation, polariton lasing, polariton-based quantum transduction schemes, and polariton chemistry.
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Affiliation(s)
- Woo Je Chang
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Hongfei Zeng
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | | | - Justin Provazza
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Pufan Liu
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Emily A Weiss
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Nathaniel P Stern
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Roel Tempelaar
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
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5
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Klepzig LF, Keppler NC, Rudolph DA, Schaate A, Behrens P, Lauth J. Highly Transparent, Yet Photoluminescent: 2D CdSe/CdS Nanoplatelet-Zeolitic Imidazolate Framework Composites Sensitive to Gas Adsorption. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309533. [PMID: 38078785 DOI: 10.1002/smll.202309533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Indexed: 05/03/2024]
Abstract
In this work, thin composite films of zeolitic imidazolate frameworks (ZIFs) and colloidal two-dimensional (2D) core-crown CdSe/CdS nanoplatelet (NPL) emitters with minimal scattering are formed by a cycled growth method and yield highly transparent coatings with strong and narrow photoluminescence of the NPLs at 546 nm (FWHM: 25 nm) in a solid-state composite structure. The porous ZIF matrix acts as functional encapsulation for the emitters and enables the adsorption of the guest molecules water and ethanol. The adsorption and desorption of the guest molecules is then characterized by a reversable photoluminescence change of the embedded NPLs. The transmittance of the composite films exceeds the values of uncoated glass at visible wavelengths where the NPL emitters show no absorption (>540 nm) and renders them anti-reflective coatings. At NPL absorption wavelengths (440-540 nm), the transmittance of the thin composite film-coated glass lies close to the transmittance of uncoated glass. The fast formation of innovative, smooth NPL/ZIF composite films without pre-polymerizing the colloidal 2D nanostructures first provides a powerful tool toward application-oriented photoluminescence-based gas sensing.
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Affiliation(s)
- Lars F Klepzig
- Institute of Physical Chemistry, Leibniz University Hannover, Callinstraße 3A, D-30167, Hannover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Leibniz University Hannover, Welfengarten 1A, D-30167, Hannover, Germany
| | - Nils C Keppler
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Leibniz University Hannover, Welfengarten 1A, D-30167, Hannover, Germany
- Institute of Inorganic Chemistry, Leibniz University Hannover, Callinstraße 9, D-30167, Hannover, Germany
| | - Dominik A Rudolph
- Institute of Physical Chemistry, Leibniz University Hannover, Callinstraße 3A, D-30167, Hannover, Germany
| | - Andreas Schaate
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Leibniz University Hannover, Welfengarten 1A, D-30167, Hannover, Germany
- Institute of Inorganic Chemistry, Leibniz University Hannover, Callinstraße 9, D-30167, Hannover, Germany
- Laboratory of Nano and Quantum Engineering (LNQE), Leibniz University Hannover, Schneiderberg 39, D-30167, Hannover, Germany
| | - Peter Behrens
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Leibniz University Hannover, Welfengarten 1A, D-30167, Hannover, Germany
- Institute of Inorganic Chemistry, Leibniz University Hannover, Callinstraße 9, D-30167, Hannover, Germany
- Laboratory of Nano and Quantum Engineering (LNQE), Leibniz University Hannover, Schneiderberg 39, D-30167, Hannover, Germany
| | - Jannika Lauth
- Institute of Physical Chemistry, Leibniz University Hannover, Callinstraße 3A, D-30167, Hannover, Germany
- Cluster of Excellence PhoenixD (Photonics, Optics and Engineering - Innovation Across Disciplines), Leibniz University Hannover, Welfengarten 1A, D-30167, Hannover, Germany
- Laboratory of Nano and Quantum Engineering (LNQE), Leibniz University Hannover, Schneiderberg 39, D-30167, Hannover, Germany
- Institute of Physical Chemistry and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-30167, Tübingen, Germany
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6
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Li Y, Wang L, Xiang D, Zhu J, Wu K. Dielectric and Wavefunction Engineering of Electron Spin Lifetime in Colloidal Nanoplatelet Heterostructures. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306518. [PMID: 38234238 DOI: 10.1002/advs.202306518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/23/2023] [Indexed: 01/19/2024]
Abstract
Colloidal semiconductor nanoplatelets (NPLs) have emerged as low-cost and free-standing alternates of traditional quantum wells. The giant heavy- and light-hole splitting in NPLs allows for efficient optical spin injection. However, the electron spin lifetimes for prototypical CdSe NPLs are within a few picoseconds, likely limited by strong electron-hole exchange in these quantum- and dielectric-confined materials. Here how this hurdle can be overcome with engineered NPL-heterostructures is demonstrated. By constructing type-I CdSe/ZnS core/shell NPLs, dielectric screening inside the core is strongly enhanced, prolonging the electron spin polarization time (τesp) to over 30 ps (or 60 ps electron spin-flip time). Alternatively, by growing type-II CdSe/CdTe core/crown NPLs to spatially separate electron and hole wavefunctions, the electron-hole exchange is strongly suppressed, resulting in τesp as long as 300 ps at room temperature. This study not only exemplifies how the well-established synthetic chemistry of colloidal heterostructures can aid in spin dynamics control but also establishes the feasibility of room-temperature coherent spin manipulation in colloidal NPLs.
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Affiliation(s)
- Yulu Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Lifeng Wang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
- University of the Chinese Academy of Sciences, Beijing, Hebei, 100049, China
| | - Dongmei Xiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Jingyi Zhu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Kaifeng Wu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
- University of the Chinese Academy of Sciences, Beijing, Hebei, 100049, China
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7
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Zhu C, Boehme SC, Feld LG, Moskalenko A, Dirin DN, Mahrt RF, Stöferle T, Bodnarchuk MI, Efros AL, Sercel PC, Kovalenko MV, Rainò G. Single-photon superradiance in individual caesium lead halide quantum dots. Nature 2024; 626:535-541. [PMID: 38297126 PMCID: PMC10866711 DOI: 10.1038/s41586-023-07001-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 12/19/2023] [Indexed: 02/02/2024]
Abstract
The brightness of an emitter is ultimately described by Fermi's golden rule, with a radiative rate proportional to its oscillator strength times the local density of photonic states. As the oscillator strength is an intrinsic material property, the quest for ever brighter emission has relied on the local density of photonic states engineering, using dielectric or plasmonic resonators1,2. By contrast, a much less explored avenue is to boost the oscillator strength, and hence the emission rate, using a collective behaviour termed superradiance. Recently, it was proposed3 that the latter can be realized using the giant oscillator-strength transitions of a weakly confined exciton in a quantum well when its coherent motion extends over many unit cells. Here we demonstrate single-photon superradiance in perovskite quantum dots with a sub-100 picosecond radiative decay time, almost as short as the reported exciton coherence time4. The characteristic dependence of radiative rates on the size, composition and temperature of the quantum dot suggests the formation of giant transition dipoles, as confirmed by effective-mass calculations. The results aid in the development of ultrabright, coherent quantum light sources and attest that quantum effects, for example, single-photon emission, persist in nanoparticles ten times larger than the exciton Bohr radius.
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Affiliation(s)
- Chenglian Zhu
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Simon C Boehme
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Leon G Feld
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Anastasiia Moskalenko
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Dmitry N Dirin
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | | | | | - Maryna I Bodnarchuk
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
| | - Alexander L Efros
- Center for Computational Materials Science, US Naval Research Laboratory, Washington DC, USA
| | - Peter C Sercel
- Center for Hybrid Organic Inorganic Semiconductors for Energy, Golden, CO, USA.
| | - Maksym V Kovalenko
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland.
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
| | - Gabriele Rainò
- Department of Chemistry and Applied Biosciences, Institute of Inorganic Chemistry, ETH Zürich, Zürich, Switzerland.
- Laboratory for Thin Films and Photovoltaics, Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
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8
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Movilla JL, Planelles J, Climente JI. Excitons in metal halide perovskite nanoplatelets: an effective mass description of polaronic, dielectric and quantum confinement effects. NANOSCALE ADVANCES 2023; 5:6093-6101. [PMID: 37941960 PMCID: PMC10628976 DOI: 10.1039/d3na00592e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023]
Abstract
A theoretical model for excitons confined in metal halide perovskite nanoplatelets is presented. The model accounts for quantum confinement, dielectric confinement, short and long range polaron interactions by means of effective mass theory, image charges and Haken potentials. We use it to describe the band edge exciton of MAPbI3 structures surrounded by organic ligands. It is shown that the quasi-2D quantum and dielectric confinement squeezes the exciton radius, and this in turn enhances short-range polaron effects as compared to 3D structures. Dielectric screening is then weaker than expected from the static dielectric constant. This boosts the binding energies and radiative recombination probabilities, which is a requisite to match experimental data in related systems. The thickness dependence of Coulomb polarization and self-energy potentials is in fair agreement with sophisticated atomistic models.
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Affiliation(s)
- Jose L Movilla
- Departament d'Educació i Didàctiques Específiques, Universitat Jaume I Av. Sos Baynat, s/n 12071 Castelló Spain
| | - Josep Planelles
- Departament de Química Física i Analítica, Universitat Jaume I Av. Sos Baynat, s/n 12071 Castelló Spain
| | - Juan I Climente
- Departament de Química Física i Analítica, Universitat Jaume I Av. Sos Baynat, s/n 12071 Castelló Spain
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9
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Tenney SM, Tan LA, Tan X, Sonnleitner ML, Coffey B, Williams JA, Ronquillo R, Atallah TL, Ahmed T, Caram JR. Efficient 2D to 0D Energy Transfer in HgTe Nanoplatelet-Quantum Dot Heterostructures through High-Speed Exciton Diffusion. J Phys Chem Lett 2023; 14:9456-9463. [PMID: 37830914 DOI: 10.1021/acs.jpclett.3c02168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Large area absorbers with localized defect emission are of interest for energy concentration via the antenna effect. Transfer between 2D and 0D quantum-confined structures is advantageous as it affords maximal lateral area antennas with continuously tunable emission. We report the quantum efficiency of energy transfer in in situ grown HgTe nanoplatelet (NPL)/quantum dot (QD) heterostructures to be near unity (>85%), while energy transfer in separately synthesized and well separated solutions of HgTe NPLs to QDs only reaches 47 ± 11% at considerably higher QD concentrations. Using Kinetic Monte Carlo simulations, we estimate an exciton diffusion constant of 1-10 cm2/s in HgTe NPLs, the same magnitude as that of 2D semiconductors. We also simulate in-solution energy transfer between NPLs and QDs, recovering an R-4 dependence consistent with 2D-0D near-field energy transfer even in randomly distributed NPL/QD mixtures. This highlights the advantage of NPLs 2D morphology and the efficiency of NPL/QD heterostructures and mixtures for energy harvesting.
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Affiliation(s)
- Stephanie M Tenney
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Lauren A Tan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Xuanheng Tan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Mikayla L Sonnleitner
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Belle Coffey
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Jillian A Williams
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Ricky Ronquillo
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Timothy L Atallah
- Department of Chemistry and Biochemistry, Denison University, 500 West Loop, Granville, Ohio 43023, United States
| | - Tasnim Ahmed
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Justin R Caram
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
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10
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Yuan G, Higginbotham HF, Han J, Yadav A, Kirkwood N, Mulvaney P, Bell TDM, Cole JH, Funston AM. Tuning the Photoluminescence Anisotropy of Semiconductor Nanocrystals. ACS NANO 2023; 17:19109-19120. [PMID: 37748102 DOI: 10.1021/acsnano.3c05214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Semiconductor nanocrystals are promising optoelectronic materials. Understanding their anisotropic photoluminescence is fundamental for developing quantum-dot-based devices such as light-emitting diodes, solar cells, and polarized single-photon sources. In this study, we experimentally and theoretically investigate the photoluminescence anisotropy of CdSe semiconductor nanocrystals with various shapes, including plates, rods, and spheres, with either wurtzite or zincblende structures. We use defocused wide-field microscopy to visualize the emission dipole orientation and find that spheres, rods, and plates exhibit the optical properties of 2D, 1D, and 2D emission dipoles, respectively. We rationalize the seemingly counterintuitive observation that despite having similar aspect ratios (width/length), rods and long nanoplatelets exhibit different defocused emission patterns by considering valence band structures calculated using multiband effective mass theory and the dielectric effect. The principles are extended to provide general relationships that can be used to tune the emission dipole orientation for different materials, crystalline structures, and shapes.
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Affiliation(s)
- Gangcheng Yuan
- ARC Centre of Excellence in Exciton Science, Monash University, Clayton, Victoria 3800, Australia
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | | | - Jiho Han
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Anchal Yadav
- ARC Centre of Excellence in Exciton Science, Monash University, Clayton, Victoria 3800, Australia
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Nicholas Kirkwood
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Paul Mulvaney
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Toby D M Bell
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Jared H Cole
- ARC Centre of Excellence in Exciton Science and Chemical and Quantum Physics, School of Science, RMIT University, Melbourne, 3001, Australia
| | - Alison M Funston
- ARC Centre of Excellence in Exciton Science, Monash University, Clayton, Victoria 3800, Australia
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
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11
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Bao X, Wu X, Ke Y, Wu K, Jiang C, Wu B, Li J, Yue S, Zhang S, Shi J, Du W, Zhong Y, Hu H, Bai P, Gong Y, Zhang Q, Zhang W, Liu X. Giant Out-of-Plane Exciton Emission Enhancement in Two-Dimensional Indium Selenide via a Plasmonic Nanocavity. NANO LETTERS 2023; 23:3716-3723. [PMID: 37125916 DOI: 10.1021/acs.nanolett.2c04902] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Out-of-plane (OP) exciton-based emitters in two-dimensional semiconductor materials are attractive candidates for novel photonic applications, such as radially polarized sources, integrated photonic chips, and quantum communications. However, their low quantum efficiency resulting from forbidden transitions limits their practicality. In this work, we achieve a giant enhancement of up to 34000 for OP exciton emission in indium selenide (InSe) via a designed Ag nanocube-over-Au film plasmonic nanocavity. The large photoluminescence enhancement factor (PLEF) is attributed to the induced OP local electric field (Ez) within the nanocavity, which facilitates effective OP exciton-plasmon interaction and subsequent tremendous enhancement. Moreover, the nanoantenna effect resulting from the effective interaction improves the directivity of spontaneous radiation. Our results not only reveal an effective photoluminescence enhancement approach for OP excitons but also present an avenue for designing on-chip photonic devices with an OP dipole orientation.
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Affiliation(s)
- Xiaotian Bao
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Center for Advanced Quantum Studies, Beijing Normal University, Beijing 100875, People's Republic of China
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Xianxin Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yuxuan Ke
- School of Materials Science and Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Keming Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Chuanxiu Jiang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Bo Wu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, People's Republic of China
| | - Jing Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Shuai Yue
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Shuai Zhang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jianwei Shi
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Wenna Du
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yangguang Zhong
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Huatian Hu
- Hubei Key Laboratory of Optical Information and Pattern Recognition, Wuhan Institute of Technology, Wuhan 430205, People's Republic of China
| | - Peng Bai
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Yiyang Gong
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Qing Zhang
- School of Materials Science and Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Wenkai Zhang
- Department of Physics and Applied Optics Beijing Area Major Laboratory, Center for Advanced Quantum Studies, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Xinfeng Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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12
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Jo K, Marino E, Lynch J, Jiang Z, Gogotsi N, Darlington TP, Soroush M, Schuck PJ, Borys NJ, Murray CB, Jariwala D. Direct nano-imaging of light-matter interactions in nanoscale excitonic emitters. Nat Commun 2023; 14:2649. [PMID: 37156799 PMCID: PMC10167231 DOI: 10.1038/s41467-023-38189-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 04/12/2023] [Indexed: 05/10/2023] Open
Abstract
Strong light-matter interactions in localized nano-emitters placed near metallic mirrors have been widely reported via spectroscopic studies in the optical far-field. Here, we report a near-field nano-spectroscopic study of localized nanoscale emitters on a flat Au substrate. Using quasi 2-dimensional CdSe/CdxZn1-xS nanoplatelets, we observe directional propagation on the Au substrate of surface plasmon polaritons launched from the excitons of the nanoplatelets as wave-like fringe patterns in the near-field photoluminescence maps. These fringe patterns were confirmed via extensive electromagnetic wave simulations to be standing-waves formed between the tip and the edge-up assembled nano-emitters on the substrate plane. We further report that both light confinement and in-plane emission can be engineered by tuning the surrounding dielectric environment of the nanoplatelets. Our results lead to renewed understanding of in-plane, near-field electromagnetic signal transduction from the localized nano-emitters with profound implications in nano and quantum photonics as well as resonant optoelectronics.
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Affiliation(s)
- Kiyoung Jo
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Emanuele Marino
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Via Archirafi 36, 90123, Palermo, Italy
| | - Jason Lynch
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Zhiqiao Jiang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Natalie Gogotsi
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Thomas P Darlington
- Department of Mechanical Engineering, Columbia University, New York, NY, 10027, USA
| | - Mohammad Soroush
- Departement of Physics, Montana State University, Bozeman, MT, 59717, USA
| | - P James Schuck
- Department of Mechanical Engineering, Columbia University, New York, NY, 10027, USA
| | - Nicholas J Borys
- Departement of Physics, Montana State University, Bozeman, MT, 59717, USA
| | - Christopher B Murray
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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13
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Diroll BT, Banerjee P, Shevchenko EV. Optical anisotropy of CsPbBr 3 perovskite nanoplatelets. NANO CONVERGENCE 2023; 10:18. [PMID: 37186268 PMCID: PMC10130288 DOI: 10.1186/s40580-023-00367-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/09/2023] [Indexed: 05/17/2023]
Abstract
The two-dimensional CsPbBr3 nanoplatelets have a quantum well electronic structure with a band gap tunable with sample thicknesses in discreet steps based upon the number of monolayers. The polarized optical properties of CsPbBr3 nanoplatelets are studied using fluorescence anisotropy and polarized transient absorption spectroscopies. Polarized spectroscopy shows that they have absorption and emission transitions which are strongly plane-polarized. In particular, photoluminescence excitation and transient absorption measurements reveal a band-edge polarization approaching 0.1, the limit of isotropic two-dimensional ensembles. The degree of anisotropy is found to depend on the thickness of the nanoplatelets: multiple measurements show a progressive decrease in optical anisotropy from 2 to 5 monolayer thick nanoplatelets. In turn, larger cuboidal CsPbBr3 nanocrystals, are found to have consistently positive anisotropy which may be attributed to symmetry breaking from ideal perovskite cubes. Optical measurements of anisotropy are described with respect to the theoretical framework developed to describe exciton fine structure in these materials. The observed planar absorption and emission are close to predicted values at thinner nanoplatelet sizes and follow the predicted trend in anisotropy with thickness, but with larger anisotropy than theoretical predictions. Dominant planar emission, albeit confined to the thinnest nanoplatelets, is a valuable attribute for enhanced efficiency of light-emitting devices.
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Affiliation(s)
- Benjamin T Diroll
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, 60438, USA.
| | - Progna Banerjee
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, 60438, USA
| | - Elena V Shevchenko
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, 60438, USA
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14
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Giri A, Park G, Jeong U. Layer-Structured Anisotropic Metal Chalcogenides: Recent Advances in Synthesis, Modulation, and Applications. Chem Rev 2023; 123:3329-3442. [PMID: 36719999 PMCID: PMC10103142 DOI: 10.1021/acs.chemrev.2c00455] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Indexed: 02/01/2023]
Abstract
The unique electronic and catalytic properties emerging from low symmetry anisotropic (1D and 2D) metal chalcogenides (MCs) have generated tremendous interest for use in next generation electronics, optoelectronics, electrochemical energy storage devices, and chemical sensing devices. Despite many proof-of-concept demonstrations so far, the full potential of anisotropic chalcogenides has yet to be investigated. This article provides a comprehensive overview of the recent progress made in the synthesis, mechanistic understanding, property modulation strategies, and applications of the anisotropic chalcogenides. It begins with an introduction to the basic crystal structures, and then the unique physical and chemical properties of 1D and 2D MCs. Controlled synthetic routes for anisotropic MC crystals are summarized with example advances in the solution-phase synthesis, vapor-phase synthesis, and exfoliation. Several important approaches to modulate dimensions, phases, compositions, defects, and heterostructures of anisotropic MCs are discussed. Recent significant advances in applications are highlighted for electronics, optoelectronic devices, catalysts, batteries, supercapacitors, sensing platforms, and thermoelectric devices. The article ends with prospects for future opportunities and challenges to be addressed in the academic research and practical engineering of anisotropic MCs.
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Affiliation(s)
- Anupam Giri
- Department
of Chemistry, Faculty of Science, University
of Allahabad, Prayagraj, UP-211002, India
| | - Gyeongbae Park
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology, Cheongam-Ro 77, Nam-Gu, Pohang, Gyeongbuk790-784, Korea
- Functional
Materials and Components R&D Group, Korea Institute of Industrial Technology, Gwahakdanji-ro 137-41, Sacheon-myeon, Gangneung, Gangwon-do25440, Republic of Korea
| | - Unyong Jeong
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology, Cheongam-Ro 77, Nam-Gu, Pohang, Gyeongbuk790-784, Korea
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15
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Baruj HD, Bozkaya I, Canimkurbey B, Isik AT, Shabani F, Delikanli S, Shendre S, Erdem O, Isik F, Demir HV. Highly-Directional, Highly-Efficient Solution-Processed Light-Emitting Diodes of All-Face-Down Oriented Colloidal Quantum Well Self-Assembly. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2206582. [PMID: 37021726 DOI: 10.1002/smll.202206582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 03/06/2023] [Indexed: 06/19/2023]
Abstract
Semiconductor colloidal quantum wells (CQWs) provide anisotropic emission behavior originating from their anisotropic optical transition dipole moments (TDMs). Here, solution-processed colloidal quantum well light-emitting diodes (CQW-LEDs) of a single all-face-down oriented self-assembled monolayer (SAM) film of CQWs that collectively enable a supreme level of IP TDMs at 92% in the ensemble emission are shown. This significantly enhances the outcoupling efficiency from 22% (of standard randomly-oriented emitters) to 34% (of face-down oriented emitters) in the LED. As a result, the external quantum efficiency reaches a record high level of 18.1% for the solution-processed type of CQW-LEDs, putting their efficiency performance on par with the hybrid organic-inorganic evaporation-based CQW-LEDs and all other best solution-processed LEDs. This SAM-CQW-LED architecture allows for a high maximum brightness of 19,800 cd m-2 with a long operational lifetime of 247 h at 100 cd m-2 as well as a stable saturated deep-red emission (651 nm) with a low turn-on voltage of 1.7 eV at a current density of 1 mA cm-2 and a high J90 of 99.58 mA cm-2 . These findings indicate the effectiveness of oriented self-assembly of CQWs as an electrically-driven emissive layer in improving outcoupling and external quantum efficiencies in the CQW-LEDs.
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Affiliation(s)
- Hamed Dehghanpour Baruj
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
| | - Iklim Bozkaya
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
| | - Betul Canimkurbey
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
- Central Research Laboratory, Amasya University, Amasya, 05100, Turkey
| | - Ahmet Tarik Isik
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
| | - Farzan Shabani
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
| | - Savas Delikanli
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 639798, Singapore
| | - Sushant Shendre
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 639798, Singapore
| | - Onur Erdem
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
| | - Furkan Isik
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
| | - Hilmi Volkan Demir
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, 06800, Turkey
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 639798, Singapore
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16
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Krajewska CJ, Kaplan AEK, Kick M, Berkinsky DB, Zhu H, Sverko T, Van Voorhis T, Bawendi MG. Controlled Assembly and Anomalous Thermal Expansion of Ultrathin Cesium Lead Bromide Nanoplatelets. NANO LETTERS 2023; 23:2148-2157. [PMID: 36884029 DOI: 10.1021/acs.nanolett.2c04526] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Quantum confined lead halide perovskite nanoplatelets are anisotropic materials displaying strongly bound excitons with spectrally pure photoluminescence. We report the controlled assembly of CsPbBr3 nanoplatelets through varying the evaporation rate of the dispersion solvent. We confirm the assembly of superlattices in the face-down and edge-up configurations by electron microscopy, as well as X-ray scattering and diffraction. Polarization-resolved spectroscopy shows that superlattices in the edge-up configuration display significantly polarized emission compared to face-down counterparts. Variable-temperature X-ray diffraction of both face-down and edge-up superlattices uncovers a uniaxial negative thermal expansion in ultrathin nanoplatelets, which reconciles the anomalous temperature dependence of the emission energy. Additional structural aspects are investigated by multilayer diffraction fitting, revealing a significant decrease in superlattice order with decreasing temperature, with a concomitant expansion of the organic sublattice and increase of lead halide octahedral tilt.
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Affiliation(s)
- Chantalle J Krajewska
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Alexander E K Kaplan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Matthias Kick
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - David B Berkinsky
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Hua Zhu
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Tara Sverko
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Troy Van Voorhis
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Moungi G Bawendi
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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17
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Diroll BT, Guzelturk B, Po H, Dabard C, Fu N, Makke L, Lhuillier E, Ithurria S. 2D II-VI Semiconductor Nanoplatelets: From Material Synthesis to Optoelectronic Integration. Chem Rev 2023; 123:3543-3624. [PMID: 36724544 DOI: 10.1021/acs.chemrev.2c00436] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The field of colloidal synthesis of semiconductors emerged 40 years ago and has reached a certain level of maturity thanks to the use of nanocrystals as phosphors in commercial displays. In particular, II-VI semiconductors based on cadmium, zinc, or mercury chalcogenides can now be synthesized with tailored shapes, composition by alloying, and even as nanocrystal heterostructures. Fifteen years ago, II-VI semiconductor nanoplatelets injected new ideas into this field. Indeed, despite the emergence of other promising semiconductors such as halide perovskites or 2D transition metal dichalcogenides, colloidal II-VI semiconductor nanoplatelets remain among the narrowest room-temperature emitters that can be synthesized over a wide spectral range, and they exhibit good material stability over time. Such nanoplatelets are scientifically and technologically interesting because they exhibit optical features and production advantages at the intersection of those expected from colloidal quantum dots and epitaxial quantum wells. In organic solvents, gram-scale syntheses can produce nanoparticles with the same thicknesses and optical properties without inhomogeneous broadening. In such nanoplatelets, quantum confinement is limited to one dimension, defined at the atomic scale, which allows them to be treated as quantum wells. In this review, we discuss the synthetic developments, spectroscopic properties, and applications of such nanoplatelets. Covering growth mechanisms, we explain how a thorough understanding of nanoplatelet growth has enabled the development of nanoplatelets and heterostructured nanoplatelets with multiple emission colors, spatially localized excitations, narrow emission, and high quantum yields over a wide spectral range. Moreover, nanoplatelets, with their large lateral extension and their thin short axis and low dielectric surroundings, can support one or several electron-hole pairs with large exciton binding energies. Thus, we also discuss how the relaxation processes and lifetime of the carriers and excitons are modified in nanoplatelets compared to both spherical quantum dots and epitaxial quantum wells. Finally, we explore how nanoplatelets, with their strong and narrow emission, can be considered as ideal candidates for pure-color light emitting diodes (LEDs), strong gain media for lasers, or for use in luminescent light concentrators.
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Affiliation(s)
- Benjamin T Diroll
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Burak Guzelturk
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Hong Po
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Corentin Dabard
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Ningyuan Fu
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Lina Makke
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
| | - Emmanuel Lhuillier
- Sorbonne Université, CNRS, Institut des NanoSciences de Paris, INSP, 75005 Paris, France
| | - Sandrine Ithurria
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI-Paris, PSL Research University, Sorbonne Université Univ Paris 06, CNRS UMR 8213, 10 rue Vauquelin 75005 Paris, France
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18
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Yu J, Hu S, Gao H, Delikanli S, Liu B, Jasieniak JJ, Sharma M, Demir HV. Observation of Phonon Cascades in Cu-Doped Colloidal Quantum Wells. NANO LETTERS 2022; 22:10224-10231. [PMID: 36326236 DOI: 10.1021/acs.nanolett.2c03427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Electronic doping has endowed colloidal quantum wells (CQWs) with unique optical and electronic properties, holding great potential for future optoelectronic device concepts. Unfortunately, how photogenerated hot carriers interact with phonons in these doped CQWs still remains an open question. Here, through investigating the emission properties, we have observed an efficient phonon cascade process (i.e., up to 27 longitudinal optical phonon replicas are revealed in the broad Cu emission band at room temperature) and identified a giant Huang-Rhys factor (S ≈ 12.4, more than 1 order of magnitude larger than reported values of other inorganic semiconductor nanomaterials) in Cu-doped CQWs. We argue that such an ultrastrong electron-phonon coupling in Cu-doped CQWs is due to the dopant-induced lattice distortion and the dopant-enhanced density of states. These findings break the widely accepted consensus that electron-phonon coupling is typically weak in quantum-confined systems, which are crucial for optoelectronic applications of doped electronic nanomaterials.
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Affiliation(s)
- Junhong Yu
- Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang621900, People's Republic of China
- LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore639798, Singapore
| | - Sujuan Hu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou510275, People's Republic of China
| | - Huayu Gao
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou510275, People's Republic of China
| | - Savas Delikanli
- Department of Electrical and Electronics Engineering and Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, Ankara06800, Turkey
| | - Baiquan Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou510275, People's Republic of China
| | - Jacek J Jasieniak
- ARC Centre of Excellence in Exciton Science, Department of Materials Science and Engineering, Monash University, Clayton Campus, Melbourne, Victoria3800, Australia
| | - Manoj Sharma
- LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore639798, Singapore
- ARC Centre of Excellence in Exciton Science, Department of Materials Science and Engineering, Monash University, Clayton Campus, Melbourne, Victoria3800, Australia
| | - Hilmi Volkan Demir
- LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore639798, Singapore
- Department of Electrical and Electronics Engineering and Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, Bilkent, Ankara06800, Turkey
- School of Physical and Mathematical Sciences, Division of Physics and Applied Physics, Nanyang Technological University, Singapore639798, Singapore
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19
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Marcato T, Krumeich F, Shih CJ. Confinement-Tunable Transition Dipole Moment Orientation in Perovskite Nanoplatelet Solids and Binary Blends. ACS NANO 2022; 16:18459-18471. [PMID: 36350363 DOI: 10.1021/acsnano.2c06600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Tuning the transition dipole moment (TDM) orientation in low-dimensional semiconductors is of fundamental and practical interest, as it enables high-efficiency nanophotonics and light-emitting diodes. However, despite recent progress in nanomaterials physics and chemistry, material systems that allow continuous tuning of the TDM orientation remain rare. Here, combining k-space photoluminescence spectroscopy and multiscale modeling, we demonstrate that the TDM orientation in lead halide perovskite (LHP) nanoplatelet (NPL) solids is largely confinement-tunable through the NPL geometry that regulates the anisotropy of Bloch states, dielectric confinement, and exciton fine structure. We further quantified the role of uniaxial ordering during NPL assembly in modifying the macroscopic emission directionality of thin films, which is especially important in actual optoelectronic devices. Our theoretical framework successfully corroborates the previous prediction of exciton bright level order reversal with experimental evidence of a counterintuitive reduction of in-plane dipole ratio in ultrathin (one- and two-monolayer-thick) NPLs, even at room temperature. More interestingly, the NPLs retain their TDM orientation in binary blends irrespective of interparticle energy transfer, owing to the phase segregation and NPL-NPL decoupling, enabling the design of films whose fluorescence exhibits an intrinsic angle-dependent color gradient.
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Affiliation(s)
- Tommaso Marcato
- Institute for Chemical and Bioengineering, ETH Zürich, 8093Zürich, Switzerland
| | - Frank Krumeich
- Laboratory of Inorganic Chemistry, ETH Zürich, 8093Zürich, Switzerland
| | - Chih-Jen Shih
- Institute for Chemical and Bioengineering, ETH Zürich, 8093Zürich, Switzerland
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20
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Bai P, Hu A, Deng Y, Tang Z, Yu W, Hao Y, Yang S, Zhu Y, Xiao L, Jin Y, Gao Y. CdSe/CdSeS Nanoplatelet Light-Emitting Diodes with Ultrapure Green Color and High External Quantum Efficiency. J Phys Chem Lett 2022; 13:9051-9057. [PMID: 36153736 DOI: 10.1021/acs.jpclett.2c02633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Colloidal II-VI group nanoplatelets (NPLs) possess ultranarrow emission line widths, for which they have great promise in achieving the purest display color in solution-processed light-emitting diodes (LEDs). Red NPL-LEDs have shown extremely saturated red color with high efficiency, while the green and blue ones lag far behind. Herein, we report green NPL-LEDs with the purest color in accordance with the Rec. 2020 standard and the peak external quantum efficiency (EQE) of 9.78%. By carefully controlling the aspect ratio, capping ligands, and purifications of CdSe/CdSeS core/alloyed-crown NPLs, NPL films with excellent flatness and unity photoluminescence quantum yields (PLQYs) are realized, laying a solid foundation for improving LED performance. Furthermore, via tuning the carrier injection balance, the record-high EQE for green NPL-LEDs is achieved. The electroluminescence (EL) exhibits an extremely saturated green color with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.163 0.786), which demonstrates their great potential in applications of ultrahigh-definition display technology. Our findings would help to further improve the performance of all NPL-LEDs.
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Affiliation(s)
- Peng Bai
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - An Hu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yunzhou Deng
- Key Laboratory of Excited-State Materials of Zhejiang Province, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhenyu Tang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Wenjin Yu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yanlei Hao
- Key Laboratory of Excited-State Materials of Zhejiang Province, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Shuang Yang
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yunke Zhu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Lixin Xiao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yizheng Jin
- Key Laboratory of Excited-State Materials of Zhejiang Province, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yunan Gao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
- Frontiers Science Center for Nano-optoelectronics, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
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21
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Li F, Klepzig LF, Keppler N, Behrens P, Bigall NC, Menzel H, Lauth J. Layer-by-Layer Deposition of 2D CdSe/CdS Nanoplatelets and Polymers for Photoluminescent Composite Materials. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:11149-11159. [PMID: 36067458 DOI: 10.1021/acs.langmuir.2c00455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two-dimensional (2D) semiconductor nanoplatelets (NPLs) are strongly photoluminescent materials with interesting properties for optoelectronics. Especially their narrow photoluminescence paired with a high quantum yield is promising for light emission applications with high color purity. However, retaining these features in solid-state thin films together with an efficient encapsulation of the NPLs is a challenge, especially when trying to achieve high-quality films with a defined optical density and low surface roughness. Here, we show photoluminescent polymer-encapsulated inorganic-organic nanocomposite coatings of 2D CdSe/CdS NPLs in poly(diallyldimethylammonium chloride) (PDDA) and poly(ethylenimine) (PEI), which are prepared by sequential layer-by-layer (LbL) deposition. The electrostatic interaction between the positively charged polyelectrolytes and aqueous phase-transferred NPLs with negatively charged surface ligands is used as a driving force to achieve self-assembled nanocomposite coatings with a well-controlled layer thickness and surface roughness. Increasing the repulsive forces between the NPLs by increasing the pH value of the dispersion leads to the formation of nanocomposites with all NPLs arranging flat on the substrate, while the surface roughness of the 165 nm (50 bilayers) thick coating decreases to Ra = 14 nm. The photoluminescence properties of the nanocomposites are determined by the atomic layer thickness of the NPLs and the 11-mercaptoundecanoic acid ligand used for their phase transfer. Both the full width at half-maximum (20.5 nm) and the position (548 nm) of the nanocomposite photoluminescence are retained in comparison to the colloidal CdSe/CdS NPLs in aqueous dispersion, while the measured photoluminescence quantum yield of 5% is competitive to state-of-the-art nanomaterial coatings. Our approach yields stable polymer-encapsulated CdSe/CdS NPLs in smooth coatings with controllable film thickness, rendering the LbL deposition technique a powerful tool for the fabrication of solid-state photoluminescent nanocomposites.
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Affiliation(s)
- Fuzhao Li
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute for Technical Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Lars F Klepzig
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
| | - Nils Keppler
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Inorganic Chemistry, Leibniz Universität Hannover, Callinstraße 9, 30167 Hannover, Germany
| | - Peter Behrens
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Inorganic Chemistry, Leibniz Universität Hannover, Callinstraße 9, 30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering, Schneiderberg 39, 30167 Hannover, Germany
| | - Nadja C Bigall
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering, Schneiderberg 39, 30167 Hannover, Germany
| | - Henning Menzel
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute for Technical Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Jannika Lauth
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering─Innovation Across Disciplines), 30167 Hannover, Germany
- Institute of Physical Chemistry and Electrochemistry, Leibniz Universität Hannover, Callinstraße 3A, 30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering, Schneiderberg 39, 30167 Hannover, Germany
- Institute of Physical and Theoretical Chemistry, Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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22
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Lee J, Yoo K, Liu H, Kang J. Sensitivity improvement of hybrid active layer containing 2D nanoplatelets for indirect x-ray detector. NANOTECHNOLOGY 2022; 33:405701. [PMID: 35760045 DOI: 10.1088/1361-6528/ac7c26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
In this paper, we attempted to improve the detection sensitivity of an indirect x-ray detector through using a hybrid active layer composed of a poly [N-90-heptadecanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10,30-benzothiadiazole)] (PCDTBT) organic semiconductor and cadmium selenide nanoplatelets (CdSe NPLs) colloidal inorganic semiconductors. First, different blending ratio in the active layer (i.e. 2:1, 1:1, 1:2 and 1:3) of PCDTBT:CdSe NPL were examined, a sensitivity of 89.5μC·Gyair-1·cm-2was achieved using a 1:1 ratio due to the low series resistance (RS) and defect density in this configuration. Then, the oleic acid (OA) that was initially applied in the CdSe NPL surface was replaced with pyridine ligands, this was done because the pyridine ligand is a short-chain ligand that can help charge transfer by reducing the distance between NPLs in the active layer. In addition, an experiment was conducted to determine the optimal ligand exchange time. A detector with an PCDTBT:CdSe NPL active layer fabricated using pyridine ligand exchange achieved a sensitivity of 219.8μC·Gyair-1·cm-2after an exchange time of 12 h, this is an improvement of 155% compared to the detector using a PCDTBT:CdSe NPL with the original OA ligands. Lastly, the optimal thickness for the PCDTBT:CdSe NPL active layer was investigated. The highest mobility of 7.60 × 10- 6cm2/V·s was recorded after fabricating the layer using spin-coating at 1900 rpm, the highest sensitivity of 314.0μC·Gyair-1·cm-2was also achieved under these conditions. Compared to the initial state of the detector, our modifications improved the sensitivity of the PCDTBT:CdSe NPL detector by 251%.
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Affiliation(s)
- Jehoon Lee
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
| | - Kyunghan Yoo
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
| | - Hailiang Liu
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
| | - Jungwon Kang
- Department of Electronic and Electrical Engineering, Dankook University, Yongin-si 16890, Republic of Korea
- Convergence Semiconductor Research Center, Dankook University, Yongin-si 16890, Republic of Korea
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23
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Kumar S, Marcato T, Krumeich F, Li YT, Chiu YC, Shih CJ. Anisotropic nanocrystal superlattices overcoming intrinsic light outcoupling efficiency limit in perovskite quantum dot light-emitting diodes. Nat Commun 2022; 13:2106. [PMID: 35440650 PMCID: PMC9018755 DOI: 10.1038/s41467-022-29812-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 03/31/2022] [Indexed: 12/17/2022] Open
Abstract
Quantum dot (QD) light-emitting diodes (LEDs) are emerging as one of the most promising candidates for next-generation displays. However, their intrinsic light outcoupling efficiency remains considerably lower than the organic counterpart, because it is not yet possible to control the transition-dipole-moment (TDM) orientation in QD solids at device level. Here, using the colloidal lead halide perovskite anisotropic nanocrystals (ANCs) as a model system, we report a directed self-assembly approach to form the anisotropic nanocrystal superlattices (ANSLs). Emission polarization in individual ANCs rescales the radiation from horizontal and vertical transition dipoles, effectively resulting in preferentially horizontal TDM orientation. Based on the emissive thin films comprised of ANSLs, we demonstrate an enhanced ratio of horizontal dipole up to 0.75, enhancing the theoretical light outcoupling efficiency of greater than 30%. Our optimized single-junction QD LEDs showed peak external quantum efficiency of up to 24.96%, comparable to state-of-the-art organic LEDs. Controlling the transition-dipole-moment orientation in quantum dot solids at device level has not been achieved before. Here, the authors demonstrated intrinsic light out-coupling enhancement approach to boost the external quantum efficiency up to 25% by using the colloidal lead halide perovskite anisotropic nanocrystals.
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Affiliation(s)
- Sudhir Kumar
- Institute for Chemical and Bioengineering, ETH Zürich, 8093, Zürich, Switzerland
| | - Tommaso Marcato
- Institute for Chemical and Bioengineering, ETH Zürich, 8093, Zürich, Switzerland
| | - Frank Krumeich
- Laboratory of Inorganic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Yen-Ting Li
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC.,National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan, ROC
| | - Yu-Cheng Chiu
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, 10607, Taiwan, ROC
| | - Chih-Jen Shih
- Institute for Chemical and Bioengineering, ETH Zürich, 8093, Zürich, Switzerland.
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24
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Katznelson S, Cohn B, Sufrin S, Amit T, Mukherjee S, Kleiner V, Mohapatra P, Patsha A, Ismach A, Refaely-Abramson S, Hasman E, Koren E. Bright excitonic multiplexing mediated by dark exciton transition in two-dimensional TMDCs at room temperature. MATERIALS HORIZONS 2022; 9:1089-1098. [PMID: 35083477 DOI: 10.1039/d1mh01186c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
2D-semiconductors with strong light-matter interaction are attractive materials for integrated and tunable optical devices. Here, we demonstrate room-temperature wavelength multiplexing of the two-primary bright excitonic channels (Ab-, Bb-) in monolayer transition metal dichalcogenides (TMDs) arising from a dark exciton mediated transition. We present how tuning dark excitons via an out-of-plane electric field cedes the system equilibrium from one excitonic channel to the other, encoding the field polarization into wavelength information. In addition, we demonstrate how such exciton multiplexing is dictated by thermal-scattering by performing temperature dependent photoluminescence measurements. Finally, we demonstrate experimentally and theoretically how excitonic mixing can explain preferable decay through dark states in MoX2 in comparison with WX2 monolayers. Such field polarization-based manipulation of excitonic transitions can pave the way for novel photonic device architectures.
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Affiliation(s)
- Shaul Katznelson
- Nanoscale Electronic Materials and Devices Laboratory, Faculty of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
- Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Bar Cohn
- Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Atomic-Scale Photonics Laboratory, Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Shmuel Sufrin
- Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Atomic-Scale Photonics Laboratory, Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Tomer Amit
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Subhrajit Mukherjee
- Nanoscale Electronic Materials and Devices Laboratory, Faculty of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
| | - Vladimir Kleiner
- Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Atomic-Scale Photonics Laboratory, Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Pranab Mohapatra
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Avinash Patsha
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Ariel Ismach
- Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv, Tel Aviv, 6997801, Israel
| | - Sivan Refaely-Abramson
- Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Erez Hasman
- Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- Atomic-Scale Photonics Laboratory, Faculty of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Elad Koren
- Nanoscale Electronic Materials and Devices Laboratory, Faculty of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel.
- Russell Berrie Nanotechnology Institute, and Helen Diller Quantum Center, Technion - Israel Institute of Technology, Haifa 3200003, Israel
- The Nancy and Stephen Grand Technion Energy Program, Technion - Israel Institute of Technology, Haifa 3200003, Israel
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25
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Song Y, Liu R, Wang Z, Xu H, Ma Y, Fan F, Voznyy O, Du J. Enhanced emission directivity from asymmetrically strained colloidal quantum dots. SCIENCE ADVANCES 2022; 8:eabl8219. [PMID: 35196093 PMCID: PMC8865764 DOI: 10.1126/sciadv.abl8219] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 12/28/2021] [Indexed: 06/14/2023]
Abstract
Current state-of-the-art quantum dot light-emitting diodes have reached close to unity internal quantum efficiency. Further improvement in external quantum efficiency requires more efficient photon out-coupling. Improving the directivity of the photon emission is considered to be the most feasible approach. Here, we report improved emission directivity from colloidal quantum dot films. By growing an asymmetric compressive shell, we are able to lift their band-edge state degeneracy, which leads to an overwhelming population of exciton with in-plane dipole moment, as desired for high-efficiency photon out-coupling. The in-plane dipole proportion determined by back-focal plane imaging method is 88%, remarkably higher than 70% obtained from conventional hydrostatically strained colloidal quantum dots. Enhanced emission directivity obtained here opens a path to increasing the external quantum efficiencies notably.
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Affiliation(s)
- Yang Song
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Key Laboratory of Microscale Magnetic Resonance, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ruixiang Liu
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Key Laboratory of Microscale Magnetic Resonance, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zhibo Wang
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Huaiyu Xu
- CAS Key Laboratory of Microscale Magnetic Resonance, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yong Ma
- College of Photoelectronic Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China
| | - Fengjia Fan
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Key Laboratory of Microscale Magnetic Resonance, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Oleksandr Voznyy
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Jiangfeng Du
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Key Laboratory of Microscale Magnetic Resonance, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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26
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Villamil Franco C, Trippé-Allard G, Mahler B, Cornaggia C, Lauret JS, Gustavsson T, Cassette E. Exciton Cooling in 2D Perovskite Nanoplatelets: Rationalized Carrier-Induced Stark and Phonon Bottleneck Effects. J Phys Chem Lett 2022; 13:393-399. [PMID: 34985898 DOI: 10.1021/acs.jpclett.1c03894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Using femtosecond transient absorption (fs-TA), we investigate the hot exciton relaxation dynamics in strongly confined lead iodide perovskite nanoplatelets (NPLs). The large quantum and dielectric confinement leads to discrete excitonic transitions and strong Stark features in the TA spectra. This prevents the use of conventional relaxation analysis methods extracting the carrier temperature or measuring the buildup of the band-edge bleaching. Instead, we show that the TA spectral line shape near the band-edge reflects the state of the system, which can be used to probe the exciton cooling dynamics. The ultrafast hot exciton relaxation in one- to three- monolayer-thick NPLs confirms the absence of intrinsic phonon bottleneck. However, excitation fluence-dependent measurements reveal a hot phonon bottleneck effect, which is found to be independent of the nature of the internal cations but strongly affected by the ligands and/or sample surface state. Together, these results suggest a role of the surface ligands in the cooling process.
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Affiliation(s)
- Carolina Villamil Franco
- Université Paris-Saclay, CEA, CNRS, Laboratoire Interactions, Dynamiques et Lasers (LIDYL), 91191 Gif-sur-Yvette, France
| | - Gaëlle Trippé-Allard
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, CentraleSupélec, Laboratoire Lumière, Matière et Interfaces (LuMIn), 91405 Orsay, France
| | - Benoît Mahler
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière (iLM),, F-69622 Villeurbanne, France
| | - Christian Cornaggia
- Université Paris-Saclay, CEA, CNRS, Laboratoire Interactions, Dynamiques et Lasers (LIDYL), 91191 Gif-sur-Yvette, France
| | - Jean-Sébastien Lauret
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, CentraleSupélec, Laboratoire Lumière, Matière et Interfaces (LuMIn), 91405 Orsay, France
| | - Thomas Gustavsson
- Université Paris-Saclay, CEA, CNRS, Laboratoire Interactions, Dynamiques et Lasers (LIDYL), 91191 Gif-sur-Yvette, France
| | - Elsa Cassette
- Université Paris-Saclay, CEA, CNRS, Laboratoire Interactions, Dynamiques et Lasers (LIDYL), 91191 Gif-sur-Yvette, France
- Université Paris-Saclay, ENS Paris-Saclay, CNRS, CentraleSupélec, Laboratoire Lumière, Matière et Interfaces (LuMIn), 91405 Orsay, France
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27
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Guillemeney L, Lermusiaux L, Landaburu G, Wagnon B, Abécassis B. Curvature and self-assembly of semi-conducting nanoplatelets. Commun Chem 2022; 5:7. [PMID: 36697722 PMCID: PMC9814859 DOI: 10.1038/s42004-021-00621-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 12/21/2021] [Indexed: 01/28/2023] Open
Abstract
Semi-conducting nanoplatelets are two-dimensional nanoparticles whose thickness is in the nanometer range and controlled at the atomic level. They have come up as a new category of nanomaterial with promising optical properties due to the efficient confinement of the exciton in the thickness direction. In this perspective, we first describe the various conformations of these 2D nanoparticles which display a variety of bent and curved geometries and present experimental evidences linking their curvature to the ligand-induced surface stress. We then focus on the assembly of nanoplatelets into superlattices to harness the particularly efficient energy transfer between them, and discuss different approaches that allow for directional control and positioning in large scale assemblies. We emphasize on the fundamental aspects of the assembly at the colloidal scale in which ligand-induced forces and kinetic effects play a dominant role. Finally, we highlight the collective properties that can be studied when a fine control over the assembly of nanoplatelets is achieved.
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Affiliation(s)
- Lilian Guillemeney
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Laurent Lermusiaux
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Guillaume Landaburu
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Benoit Wagnon
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
| | - Benjamin Abécassis
- grid.463879.70000 0004 0383 1432Univ. Lyon, ENS de Lyon, CNRS, Laboratoire de Chimie, 69342 Lyon, France
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28
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Rodà C, Salzmann BBV, Wagner I, Ussembayev Y, Chen K, Hodgkiss JM, Neyts K, Moreels I, Vanmaekelbergh D, Geiregat P. Stimulated Emission through an Electron-Hole Plasma in Colloidal CdSe Quantum Rings. NANO LETTERS 2021; 21:10062-10069. [PMID: 34842440 PMCID: PMC9113625 DOI: 10.1021/acs.nanolett.1c03501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Colloidal CdSe quantum rings (QRs) are a recently developed class of nanomaterials with a unique topology. In nanocrystals with more common shapes, such as dots and platelets, the photophysics is consistently dominated by strongly bound electron-hole pairs, so-called excitons, regardless of the charge carrier density. Here, we show that charge carriers in QRs condense into a hot uncorrelated plasma state at high density. Through strong band gap renormalization, this plasma state is able to produce broadband and sizable optical gain. The gain is limited by a second-order, yet radiative, recombination process, and the buildup is counteracted by a charge-cooling bottleneck. Our results show that weakly confined QRs offer a unique system to study uncorrelated electron-hole dynamics in nanoscale materials.
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Affiliation(s)
- Carmelita Rodà
- Physics
and Chemistry of Nanostructures, Department of Chemistry, Center for Nano and
Biophotonics, Liquid Crystals and Photonics Research Group, Department of Information
Technology, and Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, B-9000 Gent, Belgium
| | - Bastiaan B. V. Salzmann
- Debye
Institute for Nanomaterials Science, Utrecht
University, 3508 TA Utrecht, The Netherlands
| | - Isabella Wagner
- School of Chemical and Physical Sciences, Robinson Research Institute,
and MacDiarmid Institute
for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Yera Ussembayev
- Physics
and Chemistry of Nanostructures, Department of Chemistry, Center for Nano and
Biophotonics, Liquid Crystals and Photonics Research Group, Department of Information
Technology, and Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, B-9000 Gent, Belgium
| | - Kai Chen
- School of Chemical and Physical Sciences, Robinson Research Institute,
and MacDiarmid Institute
for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand
- The
Dodd-Walls Centre for Photonic and Quantum Technologies, University of Otago, Dunedin 9010, New Zealand
| | - Justin M. Hodgkiss
- School of Chemical and Physical Sciences, Robinson Research Institute,
and MacDiarmid Institute
for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Kristiaan Neyts
- Physics
and Chemistry of Nanostructures, Department of Chemistry, Center for Nano and
Biophotonics, Liquid Crystals and Photonics Research Group, Department of Information
Technology, and Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, B-9000 Gent, Belgium
| | - Iwan Moreels
- Physics
and Chemistry of Nanostructures, Department of Chemistry, Center for Nano and
Biophotonics, Liquid Crystals and Photonics Research Group, Department of Information
Technology, and Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, B-9000 Gent, Belgium
| | - Daniel Vanmaekelbergh
- Debye
Institute for Nanomaterials Science, Utrecht
University, 3508 TA Utrecht, The Netherlands
| | - Pieter Geiregat
- Physics
and Chemistry of Nanostructures, Department of Chemistry, Center for Nano and
Biophotonics, Liquid Crystals and Photonics Research Group, Department of Information
Technology, and Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, B-9000 Gent, Belgium
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29
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DeCrescent RA, Kennard RM, Chabinyc ML, Schuller JA. Optical-Frequency Magnetic Polarizability in a Layered Semiconductor. PHYSICAL REVIEW LETTERS 2021; 127:173604. [PMID: 34739261 DOI: 10.1103/physrevlett.127.173604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
The optical response of crystals is most commonly attributed to electric dipole interactions between light and matter. Although metamaterials support "artificial" magnetic resonances supported by mesoscale structuring, there are no naturally occurring materials known to exhibit a nonzero optical-frequency magnetic polarizability. Here, we experimentally demonstrate and quantify a naturally occurring nonzero magnetic polarizability in a layered semiconductor system: two-dimensional (Ruddlesden-Popper phase) hybrid organic-inorganic perovskites. These results demonstrate the only known material with an optical-frequency permeability that differs appreciably from vacuum, informing future efforts to find, synthesize, or exploit atomic-scale optical magnetism for novel optical phenomena such as negative index of refraction and electromagnetic cloaking.
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Affiliation(s)
- Ryan A DeCrescent
- Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, USA
| | - Rhys M Kennard
- Materials Department, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Michael L Chabinyc
- Materials Department, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Jon A Schuller
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106, USA
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30
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Cui J, Liu Y, Deng Y, Lin C, Fang Z, Xiang C, Bai P, Du K, Zuo X, Wen K, Gong S, He H, Ye Z, Gao Y, Tian H, Zhao B, Wang J, Jin Y. Efficient light-emitting diodes based on oriented perovskite nanoplatelets. SCIENCE ADVANCES 2021; 7:eabg8458. [PMID: 34623917 PMCID: PMC8500509 DOI: 10.1126/sciadv.abg8458] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Solution-processed planar perovskite light-emitting diodes (LEDs) promise high-performance and cost-effective electroluminescent devices ideal for large-area display and lighting applications. Exploiting emission layers with high ratios of horizontal transition dipole moments (TDMs) is expected to boost the photon outcoupling of planar LEDs. However, LEDs based on anisotropic perovskite nanoemitters remain to be inefficient (external quantum efficiency, EQE <5%) due to the difficulties of simultaneously controlling the orientations of TDMs, achieving high photoluminescence quantum yields (PLQYs) and realizing charge balance in the films of assembled nanostructures. Here, we demonstrate efficient electroluminescence from an in situ grown perovskite film composed of a monolayer of face-on oriented nanoplatelets. The ratio of horizontal TDMs of the perovskite nanoplatelet film is ~84%, which leads to a light-outcoupling efficiency of ~31%, substantially higher than that of isotropic emitters (~23%). In consequence, LEDs with a peak EQE of 23.6% are achieved, representing highly efficient planar perovskite LEDs.
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Affiliation(s)
- Jieyuan Cui
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yang Liu
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yunzhou Deng
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Chen Lin
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhishan Fang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Chensheng Xiang
- Centre of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Peng Bai
- China State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Kai Du
- Centre of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Xiaobing Zuo
- X-Ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA
| | - Kaichuan Wen
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Centre for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Shaolong Gong
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, China
| | - Haiping He
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhizhen Ye
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
- ZJU-WZ Novel Materials Science & Technology Innovation Center, Institute of Wenzhou, Zhejiang University, Wenzhou 325006, China
- Corresponding author. (Z.Y.); (Y.J.)
| | - Yunan Gao
- China State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - He Tian
- Centre of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Baodan Zhao
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310027, China
| | - Jianpu Wang
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Centre for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
| | - Yizheng Jin
- Zhejiang Key Laboratory for Excited-State Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
- Corresponding author. (Z.Y.); (Y.J.)
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31
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Liu J, Maître A, Coolen L. Tailoring Experimental Configurations to Probe Transition Dipoles of Fluorescent Nanoemitters by Polarimetry or Fourier Imaging with Enhanced Sensitivity. J Phys Chem A 2021; 125:7572-7580. [PMID: 34410716 DOI: 10.1021/acs.jpca.1c05167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Probing the transition dipoles responsible for the luminescence of a nanoemitter is essential to understanding its physical properties, its interactions with its environment, and its potential applications. Various methods in photoluminescence microscopy, based on polarimetry or Fourier imaging, have been developed to measure an emitter's dipole properties: the number of radiating dipoles, the oscillator strength ratio between them, and their orientation. In this article, we model the most used of these protocols and show that their sensitivity depends crucially on the experimental conditions: substrate material, presence of another lower or upper layer, and objective numerical aperture. We develop guidelines to optimize the measurement sensitivity by tailoring the experimental conditions, depending on the type of protocol used and the dipole property to be measured.
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Affiliation(s)
- Jiawen Liu
- Sorbonne Université, CNRS, Institut de NanoSciences de Paris, INSP, F-75005 Paris, France
| | - Agnès Maître
- Sorbonne Université, CNRS, Institut de NanoSciences de Paris, INSP, F-75005 Paris, France
| | - Laurent Coolen
- Sorbonne Université, CNRS, Institut de NanoSciences de Paris, INSP, F-75005 Paris, France
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32
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Quick MT, Owschimikow N, Achtstein AW. Terahertz Charge Carrier Mobility in 1D and 2D Semiconductor Nanoparticles. J Phys Chem Lett 2021; 12:7688-7695. [PMID: 34378384 DOI: 10.1021/acs.jpclett.1c02045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigate the charge carrier mobility in 1D and 2D semiconductor nanoparticle domains with a focus on the interpretation of THz mobility measurements. We provide a microscopic understanding of the frequency-dependent charge carrier transport in these structures of finite lateral size. Yet unexplored oscillations in the frequency-dependent complex conductivity and a strong size dependence of the mobility are observed. The quantum nature of the charge carrier states results in oscillations in the frequency-dependent mobility for subresonant THz probing, seen in experiments. The effect is based on the lack of an energy continuum for the charge motion. In 2D systems the mobility is further governed by transitions in the two orthogonal x- and y-directions and depends nontrivially on the THz polarization, as well as the quantum well lateral aspect ratio, defining the energetic detuning of the lowest THz-photon transitions in both directions. We analyze the frequency, length, and effective mass dependencies.
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Affiliation(s)
- Michael T Quick
- Institute of Optics and Atomic Physics, Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Nina Owschimikow
- Institute of Optics and Atomic Physics, Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Alexander W Achtstein
- Institute of Optics and Atomic Physics, Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
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33
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Sui X, Gao X, Wu X, Li C, Yang X, Du W, Ding Z, Jin S, Wu K, Sum TC, Gao P, Liu J, Wei X, Zhang J, Zhang Q, Tang Z, Liu X. Zone-Folded Longitudinal Acoustic Phonons Driving Self-Trapped State Emission in Colloidal CdSe Nanoplatelet Superlattices. NANO LETTERS 2021; 21:4137-4144. [PMID: 33913710 DOI: 10.1021/acs.nanolett.0c04169] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Colloidal CdSe nanoplatelets (NPLs) have substantial potential in light-emitting applications because of their quantum-well-like characteristics. The self-trapped state (STS), originating from strong electron-phonon coupling (EPC), is promising in white light luminance because of its broadband emission. However, achieving STS in CdSe NPLs is extremely challenging because of their intrinsic weak EPC nature. Herein, we developed a strong STS emission in the spectral range of 450-600 nm by building superlattice (SL) structures with colloidal CdSe NPLs. We demonstrated that STS is generated via strong coupling of excitons and zone-folded longitudinal acoustic phonons with formation time of ∼450 fs and localization length of ∼0.56 nm. The Huang-Rhys factor, describing the EPC strength in SL structure, is estimated to be ∼19.9, which is much larger than that (∼0.1) of monodispersed CdSe NPLs. Our results provide an in-depth understanding of STS and a platform for generating and manipulating STS by designing SL structures.
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Affiliation(s)
- Xinyu Sui
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Xiaoqing Gao
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, People's Republic of China
| | - Xianxin Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Chun Li
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, P.R. China
| | - Xuekang Yang
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
| | - Wenna Du
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- Key Laboratory of Semiconductor Materials Science, Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
| | - Zhengping Ding
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Shengye Jin
- State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Kaifeng Wu
- State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Tze Chien Sum
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Peng Gao
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Junjie Liu
- State Key Laboratory for Turbulence and Complex System, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, P.R. China
- Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing 100871, P.R. China
| | - Xiaoding Wei
- State Key Laboratory for Turbulence and Complex System, Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, P.R. China
- Beijing Innovation Center for Engineering Science and Advanced Technology, Peking University, Beijing 100871, P.R. China
| | - Jun Zhang
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, and Center of Materials Science and Optoelectronics Engineering, Chinese Academy of Sciences, Beijing 100083, China
| | - Qing Zhang
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, P.R. China
| | - Zhiyong Tang
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, People's Republic of China
| | - Xinfeng Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
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34
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Weiss EA. Influence of Shape Anisotropy on the Emission of Low-Dimensional Semiconductors. ACS NANO 2021; 15:3568-3577. [PMID: 33691063 DOI: 10.1021/acsnano.1c01337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The emergence of precise and scalable synthetic methods for producing anisotropic semiconductor nanostructures provides opportunities to tune the photophysical properties of these particles beyond their band gaps, and to incorporate them into higher-order structures with macroscopic anisotropic responses to electric and optical fields. This perspective article discusses some of these opportunities in the context of colloidal semiconductor nanoplatelets, with a focus on the influence of confinement anisotropy on processes that dictate the emission.
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Affiliation(s)
- Emily A Weiss
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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35
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Peric N, Lambert Y, Singh S, Khan AH, Franchina Vergel NA, Deresmes D, Berthe M, Hens Z, Moreels I, Delerue C, Grandidier B, Biadala L. Van Hove Singularities and Trap States in Two-Dimensional CdSe Nanoplatelets. NANO LETTERS 2021; 21:1702-1708. [PMID: 33544602 DOI: 10.1021/acs.nanolett.0c04509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Semiconductor nanoplatelets, which offer a compelling combination of the flatness of two-dimensional semiconductors and the inherent richness brought about by colloidal nanostructure synthesis, form an ideal and general testbed to investigate fundamental physical effects related to the dimensionality of semiconductors. With low temperature scanning tunnelling spectroscopy and tight binding calculations, we investigate the conduction band density of states of individual CdSe nanoplatelets. We find an occurrence of peaks instead of the typical steplike function associated with a quantum well, that rule out a free in-plane electron motion, in agreement with the theoretical density of states. This finding, along with the detection of deep trap states located on the edge facets, which also restrict the electron motion, provides a detailed picture of the actual lateral confinement in quantum wells with finite length and width.
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Affiliation(s)
- Nemanja Peric
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Yannick Lambert
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Shalini Singh
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Ali Hossain Khan
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Nathali Alexandra Franchina Vergel
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Dominique Deresmes
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Maxime Berthe
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Iwan Moreels
- Physics and Chemistry of Nanostructures, Ghent University, 9000 Ghent, Belgium
| | - Christophe Delerue
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Bruno Grandidier
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
| | - Louis Biadala
- Université de Lille, CNRS, Centrale Lille, Université Polytechnique Hauts-de-France, Junia-ISEN, Centrale Lille, UMR 8520 - IEMN, F-59000 Lille, France
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36
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Xiang D, Li Y, Wang L, Ding T, Wang J, Wu K. Electron and Hole Spin Relaxation in CdSe Colloidal Nanoplatelets. J Phys Chem Lett 2021; 12:86-93. [PMID: 33306386 DOI: 10.1021/acs.jpclett.0c03257] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Solution-processed quantum-confined nanocrystals are important building blocks for scalable implementation of quantum information science. Extensive studies on colloidal quantum dots (QDs) have revealed subpicosecond hole spin relaxation, whereas the electron spin dynamics remains difficult to probe. Here we study electron and hole spin dynamics in CdSe colloidal nanoplatelets (also called quantum wells) of varying thicknesses using circularly polarized transient absorption spectroscopy at room temperature. The clear spectroscopic features of transition bands associated with heavy, light, and spin-orbit split-off holes enabled separate probes of electron and hole dynamics. The hole spin-flip occurred within ∼200 fs, arising from strong spin-orbit coupling in the valence band. The electron spin lifetime decreased from 6.2 to 2.2 ps as the platelet thickness is reduced from 6 to 4 monolayers, reflecting an exchange interaction between the electron and the hole and/or surface dangling bond spins enhanced by quantum confinement.
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Affiliation(s)
- Dongmei Xiang
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Yulu Li
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Lifeng Wang
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Ding
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Junhui Wang
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Kaifeng Wu
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
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37
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Zhang Z, Thung YT, Chen X, Wang L, Fan W, Ding L, Sun H. Study of Complex Optical Constants of Neat Cadmium Selenide Nanoplatelets Thin Films by Spectroscopic Ellipsometry. J Phys Chem Lett 2021; 12:191-198. [PMID: 33325711 DOI: 10.1021/acs.jpclett.0c03304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Knowledge of tunability of complex optical constants of colloidal CdSe nanoplatelets (NPLs) thin films is essential for accurate modeling and design of NPL-containing optoelectronic devices. Here, dielectric functions, complex optical conductivities, and absorption coefficients of a series of CdSe NPL films with a varying number of atomic layers were investigated in a combination of spectroscopic ellipsometry techniques and transmittance measurements over a broad spectral range. Fine electronic structures were deciphered from the dielectric functions. Oscillator strengths at the lowest exciton resonance up to 0.62 for a series of CdSe NPL films were also determined. From our results, increasing the number of monolayers was found to boost the complex optical constants and the amplitude of the coupling strength of the fundamental exciton state mainly due to higher inorganic volume filling factors and pronounced surface passivation. Our work gives insights into both the interpretation and improvements of performance of CdSe NPL-based photoelectronic applications.
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Affiliation(s)
- Zitong Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Yi Tian Thung
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Xiaoxuan Chen
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Lin Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, 149 Yanchang Road, Shanghai 200072, China
| | - Weijun Fan
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Lu Ding
- A*STAR (Agency for Science, Technology and Research), Institute of Materials Research and Engineering, Singapore 138634, Singapore
| | - Handong Sun
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies (CDPT), School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
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38
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Achtstein AW, Ayari S, Helmrich S, Quick MT, Owschimikow N, Jaziri S, Woggon U. Tuning exciton diffusion, mobility and emission line width in CdSe nanoplatelets via lateral size. NANOSCALE 2020; 12:23521-23531. [PMID: 33225335 DOI: 10.1039/d0nr04745g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigate the lateral size tunability of the exciton diffusion coefficient and mobility in colloidal quantum wells by means of line width analysis and theoretical modeling. We show that the exciton diffusion coefficient and mobility in laterally finite 2D systems like CdSe nanoplatelets can be tuned via the lateral size and aspect ratio. The coupling to acoustic and optical phonons can be altered via the lateral size and aspect ratio of the platelets. Subsequently the exciton diffusion and mobility become tunable since these phonon scattering processes determine and limit the mobility. At 4 K the exciton mobility increases from ∼ 4 × 103 cm2 V-1 s-1 to more than 1.4 × 104 cm2 V-1 s-1 for large platelets, while there are weaker changes with size and the mobility is around 8 × 101 cm2 V-1 s-1 for large platelets at room temperature. In turn at 4 K the exciton diffusion coefficient increases with the lateral size from ∼ 1.3 cm2 s-1 to ∼ 5 cm2 s-1, while it is around half the value for large platelets at room temperature. Our experimental results are in good agreement with theoretical modeling, showing a lateral size and aspect ratio dependence. The findings open up the possibility for materials with tunable exciton mobility, diffusion or emission line width, but quasi constant transition energy. High exciton mobility is desirable e.g. for solar cells and allows efficient excitation harvesting and extraction.
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Affiliation(s)
- Alexander W Achtstein
- Institute of Optics and Atomic Physics, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
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39
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Diroll BT. Circularly Polarized Optical Stark Effect in CdSe Colloidal Quantum Wells. NANO LETTERS 2020; 20:7889-7895. [PMID: 33118352 DOI: 10.1021/acs.nanolett.0c02409] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Colloidal quantum wells, or nanoplatelets, exhibit large, circularly polarized optical Stark effects under sub-band-gap femtosecond illumination. The optical Stark effect is measured for CdSe colloidal quantum wells of several thicknesses and separately as a measure of pump photon energy, pump fluence, and temperature. These measurements show that optical Stark effects in colloidal quantum wells shift the absorption features up to 5 meV, at the intensities up to 2.9 GW·cm-2 and large detuning (>400 meV) of the pump photon energy from the band edge absorption. Optical Stark shifts are underpinned by large transition dipoles of the colloidal quantum wells (μ = 15-23 D), which are larger than those of any reported colloidal quantum dots or epitaxial quantum wells. The rapid (<500 fs), narrow band blue shift of the excitonic features under circular excitation indicates the viability of these materials beyond light emission such as spintronics or all-optical switching.
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Affiliation(s)
- Benjamin T Diroll
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
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40
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Milekhin IA, Anikin KV, Rahaman M, Rodyakina EE, Duda TA, Saidzhonov BM, Vasiliev RB, Dzhagan VM, Milekhin AG, Batsanov SA, Gutakovskii AK, Latyshev AV, Zahn DRT. Resonant plasmon enhancement of light emission from CdSe/CdS nanoplatelets on Au nanodisk arrays. J Chem Phys 2020; 153:164708. [PMID: 33138402 DOI: 10.1063/5.0025572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Semiconducting nanoplatelets (NPLs) have attracted great attention due to the superior photophysical properties compared to their quantum dot analogs. Understanding and tuning the optical and electronic properties of NPLs in a plasmonic environment is a new paradigm in the field of optoelectronics. Here, we report on the resonant plasmon enhancement of light emission including Raman scattering and photoluminescence from colloidal CdSe/CdS nanoplatelets deposited on arrays of Au nanodisks fabricated by electron beam lithography. The localized surface plasmon resonance (LSPR) of the Au nanodisk arrays can be tuned by varying the diameter of the disks. In the case of surface-enhanced Raman scattering (SERS), the Raman intensity profile follows a symmetric Gaussian shape matching the LSPR of the Au nanodisk arrays. The surface-enhanced photoluminescence (SEPL) profile of NPLs, however, follows an asymmetric Gaussian distribution highlighting a compromise between the excitation and emission enhancement mechanisms originating from energy transfer and Purcell effects. The SERS and SEPL enhancement factors depend on the nanodisk size and reach maximal values at 75 and 7, respectively, for the sizes, for which the LSPR energy of Au nanodisks coincides with interband transition energies in the semiconductor platelets. Finally, to explain the origin of the resonant enhancement behavior of SERS and SEPL, we apply a numerical simulation to calculate plasmon energies in Au nanodisk arrays and emission spectra from NPLs in such a plasmonic environment.
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Affiliation(s)
- I A Milekhin
- Semiconductor Physics, Chemnitz University of Technology, Chemnitz, Germany
| | - K V Anikin
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - M Rahaman
- Semiconductor Physics, Chemnitz University of Technology, Chemnitz, Germany
| | - E E Rodyakina
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - T A Duda
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - B M Saidzhonov
- Department of Chemistry, Moscow State University, Moscow, Russia
| | - R B Vasiliev
- Department of Chemistry, Moscow State University, Moscow, Russia
| | - V M Dzhagan
- V.E. Lashkaryov Institute of Semiconductor Physics, UA-03028 Kiev, Ukraine
| | - A G Milekhin
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - S A Batsanov
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - A K Gutakovskii
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - A V Latyshev
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - D R T Zahn
- Semiconductor Physics, Chemnitz University of Technology, Chemnitz, Germany
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41
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Radchanka A, Iodchik A, Terpinskaya T, Balashevich T, Yanchanka T, Palukoshka A, Sizova S, Oleinikov V, Feofanov A, Artemyev M. Emitters with different dimensionality: 2D cadmium chalcogenide nanoplatelets and 0D quantum dots in non-specific cell labeling and two-photon imaging. NANOTECHNOLOGY 2020; 31:435102. [PMID: 32663818 DOI: 10.1088/1361-6528/aba5b5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Since CdSe nanoplatelets were reported to have a ten-fold higher two-photon (2P) absorption coefficient as compared to quantum dots, we examined their applicability for cell labeling and 2P imaging. CdSSe/ZnCdS core-shell nanoplatelets and CdSe/ZnS quantum dots, both emitting at 585 nm were encapsulated with an amphiphilic zwitterionic polymer having slightly positive zeta potential. As measured with flow cytometry, glioma C6 cells demonstrated equally efficient uptake of nanoplatelets and quantum dots, despite the different sizes of these two types of nanoparticles. 2P fluorescence microscopy revealed ca. two orders of magnitude higher fluorescence response from nanoplatelets thus offering a chance to use them as highly efficient 2P fluorescent labels in biomedicine.
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Affiliation(s)
- Aliaksandra Radchanka
- Research Institute for Physical Chemical Problems, Belarusian State University, Minsk 220006, Belarus
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42
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Ayari S, Quick MT, Owschimikow N, Christodoulou S, Bertrand GHV, Artemyev M, Moreels I, Woggon U, Jaziri S, Achtstein AW. Tuning trion binding energy and oscillator strength in a laterally finite 2D system: CdSe nanoplatelets as a model system for trion properties. NANOSCALE 2020; 12:14448-14458. [PMID: 32618327 DOI: 10.1039/d0nr03170d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We present a theoretical study combined with experimental validations demonstrating that CdSe nanoplatelets are a model system to investigate the tunability of trions and excitons in laterally finite 2D semiconductors. Our results show that the trion binding energy can be tuned from 36 meV to 18 meV with the lateral size and decreasing aspect ratio, while the oscillator strength ratio of trions to excitons decreases. In contrast to conventional quantum dots, the trion oscillator strength in a nanoplatelet at low temperature is smaller than that of the exciton. The trion and exciton Bohr radii become lateral size tunable, e.g. from ∼3.5 to 4.8 nm for the trion. We show that dielectric screening has strong impact on these properties. By theoretical modeling of transition energies, binding energies and oscillator strength of trions and excitons and comparison with experimental findings, we demonstrate that these properties are lateral size and aspect ratio tunable and can be engineered by dielectric confinement, allowing to suppress e.g. detrimental trion emission in devices. Our results strongly impact further in-depth studies, as the demonstrated lateral size tunable trion and exciton manifold is expected to influence properties like gain mechanisms, lasing, quantum efficiency and transport even at room temperature due to the high and tunable trion binding energies.
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Affiliation(s)
- Sabrine Ayari
- Laboratoire de Physique des Materiaux, Faculte des Sciences de Bizerte, Universite de Carthage, Jarzouna 7021, Tunisia
| | - Michael T Quick
- Institute of Optics and Atomic Physics, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
| | - Nina Owschimikow
- Institute of Optics and Atomic Physics, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
| | | | | | - Mikhail Artemyev
- Research Institute for Physical Chemical Problems of Belarusian State University, 220006 Minsk, Belarus
| | - Iwan Moreels
- Department of Chemistry, Ghent University, Krijgslaan 281 - S3, 9000 Gent, Belgium
| | - Ulrike Woggon
- Institute of Optics and Atomic Physics, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
| | - Sihem Jaziri
- Laboratoire de Physique des Materiaux, Faculte des Sciences de Bizerte, Universite de Carthage, Jarzouna 7021, Tunisia and Laboratoire de Physique de la Matiere Condensee, Departement de Physique, Faculte des Sciences de Tunis, Campus Universitaire, 1060 Tunis, Tunisia
| | - Alexander W Achtstein
- Institute of Optics and Atomic Physics, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
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43
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Momper R, Zhang H, Chen S, Halim H, Johannes E, Yordanov S, Braga D, Blülle B, Doblas D, Kraus T, Bonn M, Wang HI, Riedinger A. Kinetic Control over Self-Assembly of Semiconductor Nanoplatelets. NANO LETTERS 2020; 20:4102-4110. [PMID: 32163287 PMCID: PMC7307971 DOI: 10.1021/acs.nanolett.9b05270] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/06/2020] [Indexed: 05/26/2023]
Abstract
Semiconductor nanoplatelets exhibit spectrally pure, directional fluorescence. To make polarized light emission accessible and the charge transport effective, nanoplatelets have to be collectively oriented in the solid state. We discovered that the collective nanoplatelets orientation in monolayers can be controlled kinetically by exploiting the solvent evaporation rate in self-assembly at liquid interfaces. Our method avoids insulating additives such as surfactants, making it ideally suited for optoelectronics. The monolayer films with controlled nanoplatelets orientation (edge-up or face-down) exhibit long-range ordering of transition dipole moments and macroscopically polarized light emission. Furthermore, we unveil that the substantial in-plane electronic coupling between nanoplatelets enables charge transport through a single nanoplatelets monolayer, with an efficiency that strongly depends on the orientation of the nanoplatelets. The ability to kinetically control the assembly of nanoplatelets into ordered monolayers with tunable optical and electronic properties paves the way for new applications in optoelectronic devices.
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Affiliation(s)
- Rebecca Momper
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Heng Zhang
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Shuai Chen
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Henry Halim
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Ewald Johannes
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Stoyan Yordanov
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Daniele Braga
- Fluxim AG, Katharina-Sulzer-Platz 2, 8400 Winterthur, Switzerland
| | - Balthasar Blülle
- Fluxim AG, Katharina-Sulzer-Platz 2, 8400 Winterthur, Switzerland
| | - David Doblas
- INM − Leibniz-Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
| | - Tobias Kraus
- INM − Leibniz-Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany
- Colloid
and Interface Chemistry, Saarland University, Campus D2 2, 66123 Saarbruecken, Germany
| | - Mischa Bonn
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Hai I. Wang
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Andreas Riedinger
- Max-Planck-Institute
for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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44
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Bai P, Hu A, Liu Y, Jin Y, Gao Y. Printing and In Situ Assembly of CdSe/CdS Nanoplatelets as Uniform Films with Unity In-Plane Transition Dipole Moment. J Phys Chem Lett 2020; 11:4524-4529. [PMID: 32432888 DOI: 10.1021/acs.jpclett.0c00748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Distribution of the transition dipole moments (TDMs) of light emitters can intrinsically affect the light out-coupling efficiency of planar light-emitting diodes (LEDs). Lacking the control of TDM distribution has limited the efficiency of nanocrystal-based LEDs to 20%. Here, we present a method that deposits uniform nanocrystal films with unity in-plane TDM distribution. Combining an inkjet printing technique and colloidal nanocrystal self-assembly, we achieved direct printing and in situ assembly of colloidal CdSe/CdS nanoplatelets to all orient "face-down" on various substrates. With motorized translation stages, pattern printing is realized, which demonstrates the potential for integration in industrial-scale fabrication. The method is applied to achieve uniform nanoplatelet films with unity in-plane TDM distribution on zinc-oxide films, a commonly used electron-transport layer. Thus, our work paves the way to break the light out-coupling efficiency limitation of 20% in state-of-the-art nanocrystal-based LEDs, which exclusively possess an isotropic TDM distribution.
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Affiliation(s)
- Peng Bai
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - An Hu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Yang Liu
- Centre for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yizheng Jin
- Centre for Chemistry of High-Performance & Novel Materials, State Key Laboratory of Silicon Materials, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yunan Gao
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
- Frontiers Science Center for Nano-optoelectronics, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
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45
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Dozov I, Goldmann C, Davidson P, Abécassis B. Probing permanent dipoles in CdSe nanoplatelets with transient electric birefringence. NANOSCALE 2020; 12:11040-11054. [PMID: 32373875 DOI: 10.1039/d0nr00884b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Zinc-blende CdSe semiconducting nanoplatelets (NPL) show outstanding quantum confinement properties thanks to their small, atomically-controlled, thickness. For example, they display extremely sharp absorption peaks and ultra-fast recombination rates that make them very interesting objects for optoelectronic applications. However, the presence of a ground-state electric dipole for these nanoparticles has not yet been investigated. We therefore used transient electric birefringence (TEB) to probe the electric dipole of 5-monolayer thick zinc blende CdSe NPL with a parallelepipedic shape. We studied a dilute dispersion of isolated NPL coated with branched ligands and we measured, as a function of time, the birefringence induced by DC and AC field pulses. The electro-optic behavior proves the presence of a large dipolar moment (>245 D) oriented along the length of the platelets. We then induced the slow face-to-face stacking of the NPL by adding oleic acid. In these stacks, the in-plane dipole components of consecutive NPL cancel whereas their normal components add. Moreover, interestingly, the excess polarizability tensor of the NPL stacks gives rise to an electro-optic contribution opposite to that of the electric dipole. By monitoring the TEB signal of the slowly-growing stacks over up to a year, we extracted the evolution of their average length with time and we showed that their electro-optic response can be explained by the presence of a 80 D dipolar component parallel to their normal. In spite of the 4[combining macron]3m space group of bulk zinc blende CdSe, these NPL thus bear an important ground-state dipole whose magnitude per unit volume is twice that found for wurtzite CdSe nanorods. We discuss the possible origin of this electric dipole, its consequences for the optical properties of these nanoparticles, and how it could explain their strong stacking propensity that severely hampers their colloidal stability.
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Affiliation(s)
- Ivan Dozov
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France.
| | - Claire Goldmann
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France.
| | - Patrick Davidson
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France.
| | - Benjamin Abécassis
- Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Université Paris-Sud, UMR 8502, 91405 Orsay, France. and Univ Lyon, ENS de Lyon, CNRS UMR 5182, Université Claude Bernard Lyon 1, Laboratoire de Chimie, F69342, Lyon, France
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46
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Moreels I. Let There Be Order, in Films of Colloidal CdSe 2D Nanocrystals. NANO LETTERS 2020; 20:2941-2942. [PMID: 32243174 DOI: 10.1021/acs.nanolett.0c01373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Progression from random orientation of 2D CdSe nanoplatelets to ordered close-packed thin films enables us to exploit the in-plane dipole moment of the band-edge transition on a macroscopic scale and gain control over the direction of charge and energy transport within the film. Momper et al. show how this can be achieved by tuning the solvent evaporation rate during deposition. They are able to switch from thermodynamically to kinetically controlled conditions for the film formation, resulting in ordered films with either face-down or edge-up alignment of the 2D nanoplatelets.
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Affiliation(s)
- Iwan Moreels
- Department of Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Gent, Belgium
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47
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Piveteau L, Dirin DN, Gordon CP, Walder BJ, Ong TC, Emsley L, Copéret C, Kovalenko MV. Colloidal-ALD-Grown Core/Shell CdSe/CdS Nanoplatelets as Seen by DNP Enhanced PASS-PIETA NMR Spectroscopy. NANO LETTERS 2020; 20:3003-3018. [PMID: 32078332 PMCID: PMC7227022 DOI: 10.1021/acs.nanolett.9b04870] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Ligand exchange and CdS shell growth onto colloidal CdSe nanoplatelets (NPLs) using colloidal atomic layer deposition (c-ALD) were investigated by solid-state nuclear magnetic resonance (NMR) experiments, in particular, dynamic nuclear polarization (DNP) enhanced phase adjusted spinning sidebands-phase incremented echo-train acquisition (PASS-PIETA). The improved sensitivity and resolution of DNP enhanced PASS-PIETA permits the identification and study of the core, shell, and surface species of CdSe and CdSe/CdS core/shell NPLs heterostructures at all stages of c-ALD. The cadmium chemical shielding was found to be proportionally dependent on the number and nature of coordinating chalcogen-based ligands. DFT calculations permitted the separation of the the 111/113Cd chemical shielding into its different components, revealing that the varying strength of paramagnetic and spin-orbit shielding contributions are responsible for the chemical shielding trend of cadmium chalcogenides. Overall, this study points to the roughening and increased chemical disorder at the surface during the shell growth process, which is not readily captured by the conventional characterization tools such as electron microscopy.
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Affiliation(s)
- Laura Piveteau
- Department
of Chemistry and Applied Biosciences, ETH
Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
- Empa-Swiss
Federal Laboratories for Materials Science and Technology, Dübendorf, Überlandstrasse
129, Zurich CH-8600, Switzerland
| | - Dmitry N. Dirin
- Department
of Chemistry and Applied Biosciences, ETH
Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
- Empa-Swiss
Federal Laboratories for Materials Science and Technology, Dübendorf, Überlandstrasse
129, Zurich CH-8600, Switzerland
| | - Christopher P. Gordon
- Department
of Chemistry and Applied Biosciences, ETH
Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
| | - Brennan J. Walder
- Institut
des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Ta-Chung Ong
- Department
of Chemistry and Applied Biosciences, ETH
Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
| | - Lyndon Emsley
- Institut
des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Christophe Copéret
- Department
of Chemistry and Applied Biosciences, ETH
Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
- E-mail:
| | - Maksym V. Kovalenko
- Department
of Chemistry and Applied Biosciences, ETH
Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
- Empa-Swiss
Federal Laboratories for Materials Science and Technology, Dübendorf, Überlandstrasse
129, Zurich CH-8600, Switzerland
- E-mail:
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48
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Huo C, Fong CF, Amara MR, Huang Y, Chen B, Zhang H, Guo L, Li H, Huang W, Diederichs C, Xiong Q. Optical Spectroscopy of Single Colloidal CsPbBr 3 Perovskite Nanoplatelets. NANO LETTERS 2020; 20:3673-3680. [PMID: 32212737 DOI: 10.1021/acs.nanolett.0c00611] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Optically bright lead halide perovskite nanocrystals of different morphologies ranging from nanocubes to flat nanoplatelets to elongated nanowires have been reported. The morphology of the nanocrystals is expected to affect various properties such as the band edge energy and the electron-hole exchange interaction. However, aside from nanocubes, the investigation of optical properties in the lead halide perovskite nanocrystals of different morphologies at the single emitter level has been lacking. We have performed optical spectroscopy in single CsPbBr3 nanoplatelets and observed single photon emission without blinking. Furthermore, the photoluminescence emission exhibits excitonic fine structure peaks similar to what has been previously observed in nanocubes. Our work stimulates further investigations into the excitonic and quantum optics properties when the lateral size and morphology can be further controlled in lead halide perovskite nanocrystals.
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Affiliation(s)
- Caixia Huo
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
- State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi'an 710072, China
| | - Chee Fai Fong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - Mohamed-Raouf Amara
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France
| | - Yuqing Huang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - Bo Chen
- Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore
| | - Hua Zhang
- Department of Chemistry, City University of Hong Kong, Hong Kong China
- Hong Kong Branch of National Precious Metals Material Engineering Research Center (NPMM), City University of Hong Kong, Hong Kong, China
| | - Lingjun Guo
- State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi'an 710072, China
| | - Hejun Li
- State Key Laboratory of Solidification Processing, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi'an 710072, China
| | - Wei Huang
- Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), Xi'an 710072, China
| | - Carole Diederichs
- MajuLab, International Joint Research Unit, UMI 3654, CNRS, Université Côte d'Azur, Sorbonne Université, National University of Singapore, Nanyang Technological University, 637371 Singapore
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France
| | - Qihua Xiong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
- State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
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49
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Movilla JL, Planelles J, Climente JI. Dielectric Confinement Enables Molecular Coupling in Stacked Colloidal Nanoplatelets. J Phys Chem Lett 2020; 11:3294-3300. [PMID: 32272016 DOI: 10.1021/acs.jpclett.0c00855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We show theoretically that carriers confined in semiconductor colloidal nanoplatelets (NPLs) sense the presence of neighbor, cofacially stacked NPLs in their energy spectrum. When approaching identical NPLs, the otherwise degenerate energy levels red-shift and split, forming (for large stacks) minibands that are several millielectronvolts in width. Unlike in epitaxial structures, the molecular behavior does not result from quantum tunneling but from changes in the dielectric confinement. The associated excitonic absorption spectrum shows a rich structure of bright and dark states, whose optical activity and multiplicity can be understood from reflection symmetry and Coulomb tunneling. We predict spectroscopic signatures that should confirm the formation of molecular states, whose practical realization would pave the way for the development of nanocrystal chemistry based on NPLs.
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Affiliation(s)
- José L Movilla
- Departament d'Educació i Didàctiques Específiques, Universitat Jaume I, 12080 Castelló, Spain
| | - Josep Planelles
- Departament de Química Física i Analítica, Universitat Jaume I, E-12080 Castelló de la Plana, Spain
| | - Juan I Climente
- Departament de Química Física i Analítica, Universitat Jaume I, E-12080 Castelló de la Plana, Spain
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50
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Walters G, Haeberlé L, Quintero-Bermudez R, Brodeur J, Kéna-Cohen S, Sargent EH. Directional Light Emission from Layered Metal Halide Perovskite Crystals. J Phys Chem Lett 2020; 11:3458-3465. [PMID: 32293898 DOI: 10.1021/acs.jpclett.0c00901] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Metal halide perovskites are being increasingly explored for use in light-emitting diodes (LEDs), with achievements in efficiency and brightness charted across the spectrum. One path to further boosting the fraction of useful photons generated by injected electrical charges will be to tailor the emission patterns of devices. Here we investigate directional emission from layered metal halide perovskites. We quantify the proportion of in-plane versus out-of-plane transition dipole components for a suite of layered perovskites. We find that certain perovskite single crystals have highly anisotropic emissions and up to 90% of their transition dipole in-plane. For thin films, emission anisotropy increases as the nominal layer thickness decreases and is generally greater with butylammonium cations than with phenethylammonium cations. Numerical simulations reveal that anisotropic emission from layered perovskites in thin-film LEDs may lead to external quantum efficiencies of 45%, an absolute gain of 13% over equivalent films with isotropic emitters.
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Affiliation(s)
- Grant Walters
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada
| | - Louis Haeberlé
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | - Rafael Quintero-Bermudez
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada
| | - Julien Brodeur
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | - Stéphane Kéna-Cohen
- Department of Engineering Physics, Polytechnique Montréal, Montréal, Québec H3C 3A7, Canada
| | - Edward H Sargent
- Department of Electrical and Computer Engineering, University of Toronto, 35 St. George Street, Toronto, Ontario M5S 1A4, Canada
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