1
|
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.
Collapse
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
| |
Collapse
|
2
|
Niebur A, Söll A, Haizmann P, Strolka O, Rudolph D, Tran K, Renz F, Frauendorf AP, Hübner J, Peisert H, Scheele M, Lauth J. Untangling the intertwined: metallic to semiconducting phase transition of colloidal MoS 2 nanoplatelets and nanosheets. NANOSCALE 2023; 15:5679-5688. [PMID: 36861175 DOI: 10.1039/d3nr00096f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
2D semiconducting transition metal dichalcogenides (TMDCs) are highly promising materials for future spin- and valleytronic applications and exhibit an ultrafast response to external (optical) stimuli which is essential for optoelectronics. Colloidal nanochemistry on the other hand is an emerging alternative for the synthesis of 2D TMDC nanosheet (NS) ensembles, allowing for the control of the reaction via tunable precursor and ligand chemistry. Up to now, wet-chemical colloidal syntheses yielded intertwined/agglomerated NSs with a large lateral size. Here, we show a synthesis method for 2D mono- and bilayer MoS2 nanoplatelets with a particularly small lateral size (NPLs, 7.4 nm ± 2.2 nm) and MoS2 NSs (22 nm ± 9 nm) as a reference by adjusting the molybdenum precursor concentration in the reaction. We find that in colloidal 2D MoS2 syntheses initially a mixture of the stable semiconducting and the metastable metallic crystal phase is formed. 2D MoS2 NPLs and NSs then both undergo a full transformation to the semiconducting crystal phase by the end of the reaction, which we quantify by X-ray photoelectron spectroscopy. Phase pure semiconducting MoS2 NPLs with a lateral size approaching the MoS2 exciton Bohr radius exhibit strong additional lateral confinement, leading to a drastically shortened decay of the A and B exciton which is characterized by ultrafast transient absorption spectroscopy. Our findings represent an important step for utilizing colloidal TMDCs, for example small MoS2 NPLs represent an excellent starting point for the growth of heterostructures for future colloidal photonics.
Collapse
Affiliation(s)
- André Niebur
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, D-30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering - Innovation Across Disciplines), Hannover, Germany
| | - Aljoscha Söll
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, D-30167 Hannover, Germany.
| | - Philipp Haizmann
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Onno Strolka
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, D-30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering - Innovation Across Disciplines), Hannover, Germany
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Dominik Rudolph
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, D-30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering - Innovation Across Disciplines), Hannover, Germany
| | - Kevin Tran
- Institute of Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, D-30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering (LNQE), Leibniz University Hannover, Schneiderberg 39, D-30167 Hannover, Germany
| | - Franz Renz
- Institute of Inorganic Chemistry, Leibniz University Hannover, Callinstr. 9, D-30167 Hannover, Germany
- Laboratory of Nano and Quantum Engineering (LNQE), Leibniz University Hannover, Schneiderberg 39, D-30167 Hannover, Germany
| | - André Philipp Frauendorf
- Institute of Solid State Physics, Leibniz University Hannover, Appelstr. 2, D-30167 Hannover, Germany
| | - Jens Hübner
- Laboratory of Nano and Quantum Engineering (LNQE), Leibniz University Hannover, Schneiderberg 39, D-30167 Hannover, Germany
- Institute of Solid State Physics, Leibniz University Hannover, Appelstr. 2, D-30167 Hannover, Germany
| | - Heiko Peisert
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Marcus Scheele
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Jannika Lauth
- Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, D-30167 Hannover, Germany.
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering - Innovation Across Disciplines), Hannover, Germany
- Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
- Laboratory of Nano and Quantum Engineering (LNQE), Leibniz University Hannover, Schneiderberg 39, D-30167 Hannover, Germany
| |
Collapse
|
3
|
Failla M, García Flórez F, Salzmann BBV, Vanmaekelbergh D, Stoof HTC, Siebbeles LDA. Effects of Pump Photon Energy on Generation and Ultrafast Relaxation of Excitons and Charge Carriers in CdSe Nanoplatelets. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:1899-1907. [PMID: 36761230 PMCID: PMC9900632 DOI: 10.1021/acs.jpcc.2c07292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/21/2022] [Indexed: 06/18/2023]
Abstract
We studied the initial nature and relaxation of photoexcited electronic states in CdSe nanoplatelets (NPLs). Ultrafast transient optical absorption (TA) measurements were combined with the theoretical analysis of the formation and decay of excitons, biexcitons, free charge carriers, and trions. In the latter, photons and excitons were treated as bosons and free charge carriers as fermions. The initial quantum yields of heavy-hole (HH) excitons, light-hole (LH) excitons, and charge carriers vary strongly with photon energy, while thermal relaxation occurs always within 1 ps. After that, the population of LH excitons is negligible due to relaxation to HH excitons or decay into free electrons and holes. Up to the highest average number of about four absorbed photons per NPL in our experiments, we found no signatures of the presence of biexcitons or larger complexes. Biexcitons were only observed due to the interaction of a probe-generated exciton with an exciton produced previously by the pump pulse. For higher pump photon energies, the initial presence of more free charge carriers leads to formation of trions by probe photons. On increasing the number of absorbed pump photons in an NPL, the yield of excitons becomes higher as compared to free charge carriers, since electron-hole recombination becomes more likely. In addition to a TA absorption feature at energy below the HH exciton peak, we also observed a TA signal at the high-energy side of this peak, which we attribute to formation of LH-HH biexcitons or trions consisting of a charge and LH exciton.
Collapse
Affiliation(s)
- Michele Failla
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZDelft, The Netherlands
| | - Fransisco García Flórez
- Institute
for Theoretical Physics and Center for Extreme Matter and Emergent
Phenomena, Utrecht University, Princetonplein 5, 3584 CCUtrecht, The Netherlands
| | - Bastiaan B. V. Salzmann
- Condensed
Matter and Interfaces, Debye Institute, Utrecht University, Princetonplein 1, 3584 CCUtrecht, The Netherlands
| | - Daniel Vanmaekelbergh
- Condensed
Matter and Interfaces, Debye Institute, Utrecht University, Princetonplein 1, 3584 CCUtrecht, The Netherlands
| | - Henk T. C. Stoof
- Institute
for Theoretical Physics and Center for Extreme Matter and Emergent
Phenomena, Utrecht University, Princetonplein 5, 3584 CCUtrecht, The Netherlands
| | - Laurens D. A. Siebbeles
- Chemical
Engineering Department, Delft University
of Technology, Van der Maasweg 9, 2629 HZDelft, The Netherlands
| |
Collapse
|
4
|
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: 27] [Impact Index Per Article: 27.0] [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.
Collapse
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
| |
Collapse
|
5
|
Quick MT, Ayari S, Owschimikow N, Jaziri S, Achtstein AW. THz mobility and polarizability: impact of transformation and dephasing on the spectral response of excitons in a 2D semiconductor. Phys Chem Chem Phys 2023; 25:3354-3360. [PMID: 36633188 DOI: 10.1039/d2cp03584g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We introduce a response theory based transformation for excitonic polarizability into mobility, which allows an in-depth analysis of optical pump-THz probe conductivity experiments, and compare the results with those of a conventional oscillator model. THz spectroscopy is of high interest e.g. for investigations in high bandwidth and low noise nanoelectronics or solar energy harvesting nanomaterials. In contrast to simple ω scaling of estimated static polarizability, suggested in the literature, an appropriate transformation of the spectral response into mobility can be achieved in principle forward and backward due to the presence of dephasing, as we show for the exemplary system of CdSe nanoplatelets. Common analysis approaches capture the excitonic properties only under specific conditions, and do not apply in many cases. We demonstrate that a thermal distribution of excitons and transitions between higher states in general have to be considered and that dephasing has to be taken into account for a proper transformation at all temperatures. The presented in-depth understanding of the exciton mobility in nanoparticles can help improve e.g. solar hydrogen generation, charge extraction efficiencies of solar cells, or light emission performance of LEDs.
Collapse
Affiliation(s)
- Michael T Quick
- Institute of Optics and Atomic Physics, Technische Universität Berlin, 10623, Berlin, Germany.
| | - Sabrine Ayari
- Laboratoire de Physique de l'École normale supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris-Diderot, Sorbonne Paris Cité, Paris, France
| | - Nina Owschimikow
- Institute of Optics and Atomic Physics, Technische Universität Berlin, 10623, Berlin, Germany.
| | - Sihem Jaziri
- Laboratoire de Physique des Matériaux Structure et Propriétés, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Condensée, Département de Physique, Université Tunis el Manar, Campus Universitaire 2092 Tunis, Tunisia.,Laboratoire de Physique des Materiaux, Faculte des Sciences de Bizerte, Universite de Carthage, Jarzouna, 7021, Tunisia
| | - Alexander W Achtstein
- Institute of Optics and Atomic Physics, Technische Universität Berlin, 10623, Berlin, Germany.
| |
Collapse
|
6
|
Bai B, Zhang C, Dou Y, Kong L, Wang L, Wang S, Li J, Zhou Y, Liu L, Liu B, Zhang X, Hadar I, Bekenstein Y, Wang A, Yin Z, Turyanska L, Feldmann J, Yang X, Jia G. Atomically flat semiconductor nanoplatelets for light-emitting applications. Chem Soc Rev 2023; 52:318-360. [PMID: 36533300 DOI: 10.1039/d2cs00130f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The last decade has witnessed extensive breakthroughs and significant progress in atomically flat two-dimensional (2D) semiconductor nanoplatelets (NPLs) in terms of synthesis, growth mechanisms, optical and electronic properties and practical applications. Such NPLs have electronic structures similar to those of quantum wells in which excitons are predominantly confined along the vertical direction, while electrons are free to move in the lateral directions, resulting in unique optical properties, such as extremely narrow emission line width, short photoluminescence (PL) lifetime, high gain coefficient, and giant oscillator strength transition (GOST). These unique optical properties make NPLs favorable for high color purity light-emitting applications, in particular in light-emitting diodes (LEDs), backlights for liquid crystal displays (LCDs) and lasers. This review article first introduces the intrinsic characteristics of 2D semiconductor NPLs with atomic flatness. Subsequently, the approaches and mechanisms for the controlled synthesis of atomically flat NPLs are summarized followed by an insight on recent progress in the mediation of core/shell, core/crown and core/crown@shell structures by selective epitaxial growth of passivation layers on different planes of NPLs. Moreover, an overview of the unique optical properties and the associated light-emitting applications is elaborated. Despite great progress in this research field, there are some issues relating to heavy metal elements such as Cd2+ in NPLs, and the ambiguous gain mechanisms of NPLs and others are the main obstacles that prevent NPLs from widespread applications. Therefore, a perspective is included at the end of this review article, in which the current challenges in this stimulating research field are discussed and possible solutions to tackle these challenges are proposed.
Collapse
Affiliation(s)
- Bing Bai
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henaon University, Kaifeng 475004, China
| | - Chengxi Zhang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China.
| | - Yongjiang Dou
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China.
| | - Lingmei Kong
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China.
| | - Lin Wang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China.
| | - Sheng Wang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China.
| | - Jun Li
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henaon University, Kaifeng 475004, China
| | - Yi Zhou
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henaon University, Kaifeng 475004, China
| | - Long Liu
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, School of Materials Science and Engineering, and Collaborative Innovation Center of Nano Functional Materials and Applications, Henaon University, Kaifeng 475004, China
| | - Baiquan Liu
- School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xiaoyu Zhang
- Key Laboratory of Automobile Materials, Ministry of Education, College of Materials Science and Engineering, Jilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy Materials, Electron Microscopy Center, Jilin University, Changchun 130012, China
| | - Ido Hadar
- Institute of Chemistry, and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yehonadav Bekenstein
- Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Aixiang Wang
- School of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, P. R. China
| | - Zongyou Yin
- Research School of Chemistry, The Australian National University, ACT 2601, Australia
| | - Lyudmila Turyanska
- Faculty of Engineering, The University of Nottingham, Additive Manufacturing Building, Jubilee Campus, University Park, Nottingham NG7 2RD, UK
| | - Jochen Feldmann
- Chair for Photonics and Optoelectronics, Nano-Institute Munich and Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstr. 10, Munich 80539, Germany
| | - Xuyong Yang
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China.
| | - Guohua Jia
- School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia.
| |
Collapse
|
7
|
Rodà C, Geiregat P, Di Giacomo A, Moreels I, Hens Z. Area-Independence of the Biexciton Oscillator Strength in CdSe Colloidal Nanoplatelets. NANO LETTERS 2022; 22:9537-9543. [PMID: 36409988 DOI: 10.1021/acs.nanolett.2c03683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Colloidal CdSe nanoplatelets (NPLs) are unique systems to study two-dimensional excitons and excitonic complexes. However, while absorption and emission of photons through exciton formation and recombination have been extensively quantified, few studies have addressed the exciton-biexciton transition. Here, we use cross-polarized pump-probe spectroscopy to measure the absorption coefficient spectrum of this transition and determine the biexciton oscillator strength (fBX). We show that fBX is independent of the NPL area and that the concomitant biexciton area (SBX) agrees with predictions of a short-range interaction model. Moreover, we show that fBX is comparable to the oscillator strength of forming localized excitons at room temperature while being unaffected itself by center-of-mass localization. These results confirm the relevance of biexcitons for light-matter interaction in NPLs. Moreover, the quantification of the exciton-biexciton transition introduced here will enable researchers to rank 2D materials by the strength of this transition and to compare experimental results with theoretical predictions.
Collapse
Affiliation(s)
- Carmelita Rodà
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, 9000Gent, Belgium
- NB-Photonics, Center for Nano- and Biophotonics, Ghent University, 9000Gent, Belgium
| | - Pieter Geiregat
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, 9000Gent, Belgium
- NB-Photonics, Center for Nano- and Biophotonics, Ghent University, 9000Gent, Belgium
| | - Alessio Di Giacomo
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, 9000Gent, Belgium
- NB-Photonics, Center for Nano- and Biophotonics, Ghent University, 9000Gent, Belgium
| | - Iwan Moreels
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, 9000Gent, Belgium
- NB-Photonics, Center for Nano- and Biophotonics, Ghent University, 9000Gent, Belgium
| | - Zeger Hens
- Physics and Chemistry of Nanostructures, Department of Chemistry, Ghent University, 9000Gent, Belgium
- NB-Photonics, Center for Nano- and Biophotonics, Ghent University, 9000Gent, Belgium
| |
Collapse
|
8
|
Brumberg A, Watkins NE, Diroll BT, Schaller RD. Acceleration of Biexciton Radiative Recombination at Low Temperature in CdSe Nanoplatelets. NANO LETTERS 2022; 22:6997-7004. [PMID: 36018835 DOI: 10.1021/acs.nanolett.2c01791] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Colloidal semiconductor nanocrystals offer bandgap tunability, high photoluminescence quantum yield, and colloidal processing of benefit to optoelectronics, however rapid nonradiative Auger recombination (AR) deleteriously affects device efficiencies at elevated excitation intensities. AR is understood to transition from temperature-dependent behavior in bulk semiconductors to temperature-independent behavior in zero-dimensional quantum dots (QDs) as a result of discretized band structure that facilitates satisfaction of linear momentum conservation. For nanoplatelets (NPLs), two-dimensional morphology renders prediction of photophysical behaviors challenging. Here, we investigate and compare the temperature dependence of excited-stated lifetime and fluence-dependent emission of CdSe NPLs and QDs. For NPLs, upon temperature reduction, biexciton lifetime surprisingly decreases (even becoming shorter lived than trion emission) and emission intensity increases nearly linearly with fluence rather than saturating, consistent with dominance of radiative recombination rather than AR. CdSe NPLs thus differ fundamentally from core-only QDs and foster increased utility of photogenerated excitons and multiexcitons at low temperatures.
Collapse
Affiliation(s)
- Alexandra Brumberg
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Nicolas E Watkins
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - Benjamin T Diroll
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Richard D Schaller
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
| |
Collapse
|
9
|
Macias-Pinilla DF, Planelles J, Climente JI. Biexcitons in CdSe nanoplatelets: geometry, binding energy and radiative rate. NANOSCALE 2022; 14:8493-8500. [PMID: 35662303 DOI: 10.1039/d2nr01354a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Biexciton properties in semiconductor nanostructures are highly sensitive to quantum confinement, relative electron-hole masses, dielectric environment and Coulomb correlations. Here we present a variational Quantum Monte Carlo model which, coupled to effective mass Hamiltonians, takes into account all of the above effects. The model is used to provide theoretical assessment on the biexciton ground state properties in colloidal CdSe nanoplatelets. A number of characteristic features is observed: (i) the finite thickness of these systems makes the biexciton geometry depart from the planar square expected in the two-dimensional (2D) limit, and form a distorted tetrahedron instead; (ii) the strong dielectric confinement enhances not only Coulomb attractions but also repulsions, which lowers the ratio of the biexciton-to-exciton binding energy down to EXXb/EXb = 0.07. (iii) EXXb is less sensitive than EXb to lateral confinement, and yet it can reach values above 30 meV, thus granting room temperature stability; (iv) the ratio of biexciton-to-exciton radiative rates, kradXX/kradX, decreases from 3.5 to ∼1 as the platelet area increases. These results pave the way for the rational design of biexciton properties in metal chalcogenide nanoplatelets.
Collapse
Affiliation(s)
- David F Macias-Pinilla
- Institute of Advanced Materials (INAM), Universitat Jaume I, Av. Sos Baynat, s/n, 12071 Castelló, Spain
- Departament de Química Física i Analítica, 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.
| |
Collapse
|
10
|
Radchanka A, Hrybouskaya V, Iodchik A, Achtstein AW, Artemyev M. Zeta Potential-Based Control of CdSe/ZnS Quantum Dot Photoluminescence. J Phys Chem Lett 2022; 13:4912-4917. [PMID: 35634986 DOI: 10.1021/acs.jpclett.2c00841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The ζ-potential of a colloidal quantum dot (QD) in solution has a strong impact on its photoluminescence emission quantum yield as well as the population lifetime. In this study we show that varying the surface charged groups on CdSe/ZnS QDs allows one to tune the ζ-potential and, with it, to control the quantum yield of emission as well as the recombination dynamics. We infer that the net charge density within the slipping plane around the QD in the solution strongly affects the nonradiative recombination processes, depending on the surface charge sign and value. For zwitterionic surface groups it is possible to tune the ζ-potential and the quantum yield by pH. As a general trend, QDs with zwitterionic surface groups produce a low (absolute) ζ-potential value and exhibit the highest quantum yield. Our results pave the way to, for example, future intracellular, time-resolved pH sensing applications with similar systems.
Collapse
Affiliation(s)
- Aliaksandra Radchanka
- Research Institute for Physical Chemical Problems, Belarusian State University, 220006 Minsk, Belarus
| | - Varvara Hrybouskaya
- Research Institute for Physical Chemical Problems, Belarusian State University, 220006 Minsk, Belarus
| | - Andrey Iodchik
- Research Institute for Physical Chemical Problems, Belarusian State University, 220006 Minsk, Belarus
| | - Alexander W Achtstein
- Institute of Optics and Atomic Physics, Technical University of Berlin, 10623 Berlin, Germany
| | - Mikhail Artemyev
- Research Institute for Physical Chemical Problems, Belarusian State University, 220006 Minsk, Belarus
| |
Collapse
|
11
|
Park C, Ahn S, Cha JH, Hong W, Jin HJ, Yang SY, Cho YH, Choi SY. Spatially isolated neutral excitons via clusters on trilayer MoS 2. NANOSCALE 2022; 14:4304-4311. [PMID: 35244667 DOI: 10.1039/d2nr00391k] [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
In spite of having a large exciton binding energy, two-dimensional (2D) transition metal dichalcogenides (TMDs) are limited as light-emitting materials because the spectral weight of neutral excitons decreases exponentially with increasing the excitation density. That is, neutral excitons easily transfer to trions, and exciton-exciton annihilation (EEA) occurs due to the strengthening of exciton kinetic energy in the layered structure. In here, we come up with an isolated neutral exciton system, maintaining its high spectral weight when the carrier density increased, which is achieved via MoS2 clusters on a MoS2 trilayer directly synthesized by metal-organic chemical vapor deposition (MOCVD). While increasing the excitation density, trions are decomposed by spatial confinement at the saturation level of its full width at half maximum (FWHM), and simultaneously the spectral weight of neutral excitons restarts to increase. Furthermore, we reveal the causality relationship between trions and B excitons, providing a keen insight into organic interactions among radiative recombination processes in 2D TMDs.
Collapse
Affiliation(s)
- Cheolmin Park
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, KAIST, Daehakro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| | - Seonghun Ahn
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jun-Hwe Cha
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, KAIST, Daehakro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| | - Woonggi Hong
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, KAIST, Daehakro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| | - Hyeok Jun Jin
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, KAIST, Daehakro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| | - Sang Yoon Yang
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, KAIST, Daehakro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| | - Yong-Hoon Cho
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sung-Yool Choi
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Display, KAIST, Daehakro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
| |
Collapse
|
12
|
Vong AF, Irgen-Gioro S, Wu Y, Weiss EA. Origin of Low Temperature Trion Emission in CdSe Nanoplatelets. NANO LETTERS 2021; 21:10040-10046. [PMID: 34843260 DOI: 10.1021/acs.nanolett.1c03726] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Colloidal semiconductor nanoplatelets (NPLs) are a scalable materials platform for optoelectronic applications requiring fast and narrow emission, including spin-to-photon transduction within quantum information networks. In particular, three-particle negative trions of NPLs are appealing emitters since, unlike excitons, they do not have an optically "dark" sublevel. In CdSe NPLs, trion emission dominates the photoluminescence (PL) spectrum at low temperature but using them as single photon-emitting states requires more knowledge about their preparation, since trions in these materials are not directly optically accessible from the ground state. This work demonstrates, using power-dependent time-resolved transient absorptions (TA) of CdSe NPLs, that trions form via biexciton decay in 1.6 ps. The scaling of the trion population and formation lifetime with excitation power indicates that they do not form through collisional mechanisms typical for 2D materials, but rather by a unimolecular hole transfer. This work is a step toward deterministic single photon emission from trions.
Collapse
Affiliation(s)
- Albert F Vong
- Department of Materials Science and Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Shawn Irgen-Gioro
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Yue Wu
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| | - Emily A Weiss
- Department of Materials Science and Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States
| |
Collapse
|
13
|
Shi J, Sun W, Utzat H, Farahvash A, Gao FY, Zhang Z, Barotov U, Willard AP, Nelson KA, Bawendi MG. All-optical fluorescence blinking control in quantum dots with ultrafast mid-infrared pulses. NATURE NANOTECHNOLOGY 2021; 16:1355-1361. [PMID: 34811550 DOI: 10.1038/s41565-021-01016-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Photoluminescence intermittency is a ubiquitous phenomenon, reducing the temporal emission intensity stability of single colloidal quantum dots (QDs) and the emission quantum yield of their ensembles. Despite efforts to achieve blinking reduction by chemical engineering of the QD architecture and its environment, blinking still poses barriers to the application of QDs, particularly in single-particle tracking in biology or in single-photon sources. Here, we demonstrate a deterministic all-optical suppression of QD blinking using a compound technique of visible and mid-infrared excitation. We show that moderate-field ultrafast mid-infrared pulses (5.5 μm, 150 fs) can switch the emission from a charged, low quantum yield grey trion state to the bright exciton state in CdSe/CdS core-shell QDs, resulting in a significant reduction of the QD intensity flicker. Quantum-tunnelling simulations suggest that the mid-infrared fields remove the excess charge from trions with reduced emission quantum yield to restore higher brightness exciton emission. Our approach can be integrated with existing single-particle tracking or super-resolution microscopy techniques without any modification to the sample and translates to other emitters presenting charging-induced photoluminescence intermittencies, such as single-photon emissive defects in diamond and two-dimensional materials.
Collapse
Affiliation(s)
- Jiaojian Shi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Weiwei Sun
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Hendrik Utzat
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Ardavan Farahvash
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Frank Y Gao
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Zhuquan Zhang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ulugbek Barotov
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Adam P Willard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Keith A Nelson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Moungi G Bawendi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA.
| |
Collapse
|
14
|
Naeem N, Tahir T, Ans M, Rasool A, Aqil Shehzad R, Iqbal J. Molecular engineering strategy of naphthalimide based small donor molecules for high-performance organic solar cells. COMPUT THEOR CHEM 2021. [DOI: 10.1016/j.comptc.2021.113416] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
15
|
Ben Amara I, Boustanji H, Jaziri S. Tuning optoelectronic response of lateral core-alloyed crown nanoplatelets: type-II CdSe-CdSe 1-xTe x. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:465301. [PMID: 34412039 DOI: 10.1088/1361-648x/ac1f4e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/19/2021] [Indexed: 06/13/2023]
Abstract
We present a theoretical study showing that the exciton emission in the CdSe-CdSe1-xTexcore-alloyed crown heterostructure results from the tunable quasi-type II to pure type II behavior by adjusting the Te to Se ratio. We suggest that the direct crown exciton or interface indirect exciton or a dual emission can be tuned due to the altered conduction band offset. We also found that these different emissions are red-shifted with increasing the nanoplatelets (NPLs) monolayer (ML) thickness due to the quantum confinement effect. The double exciton emission develops caused by the band bowing effect occurring in the alloyed crown. The band bowing is originated from the difference between the bonding nature of the Se and Te orbitals with the Cd orbitals in the conduction band edge states. We also found that the band bowing is sensitive on the alloyed-crown ML thickness and the in-plane strain due to hybridization magnitude between the cation (Cd) and anion (Se, Te). Our results are in accord with the available experimental data. We propose the CdSe-CdSe1-xTexcore-alloyed crown NPLs as a promising contender for the near-infrared-emitting heterostructures preparation used for light-harvesting applications.
Collapse
Affiliation(s)
- Imen Ben Amara
- Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Condensée, Université Tunis el Manar, Campus Universitaire 2092 Tunis, Tunisia
| | - Hela Boustanji
- Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Condensée, Université Tunis el Manar, Campus Universitaire 2092 Tunis, Tunisia
| | - Sihem Jaziri
- Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Condensée, Université Tunis el Manar, Campus Universitaire 2092 Tunis, Tunisia
- Faculté des Sciences de Bizerte, Laboratoire de Physique des Matériaux: Structure et Propriétés, Université de Carthage, 7021 Jarzouna, Tunisia
| |
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|
17
|
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.
Collapse
Affiliation(s)
- Alexander W Achtstein
- Institute of Optics and Atomic Physics, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
| | | | | | | | | | | | | |
Collapse
|