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Smirnova OO, Kalitukha IV, Rodina AV, Dimitriev GS, Sapega VF, Ken OS, Korenev VL, Kozyrev NV, Nekrasov SV, Kusrayev YG, Yakovlev DR, Dubertret B, Bayer M. Optical Alignment and Optical Orientation of Excitons in CdSe/CdS Colloidal Nanoplatelets. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2402. [PMID: 37686910 PMCID: PMC10489814 DOI: 10.3390/nano13172402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023]
Abstract
Optical alignment and optical orientation of excitons are studied experimentally on an ensemble of core/shell CdSe/CdS colloidal nanoplatelets. Linear and circular polarization of photoluminescence during resonant excitation of excitons is measured at cryogenic temperatures and with magnetic fields applied in the Faraday geometry. The developed theory addresses the optical alignment and optical orientation of excitons in colloidal nanocrystals, taking into account both bright and dark exciton states in the presence of strong electron-hole exchange interaction and the random in-plane orientation of nanoplatelets within the ensemble. Our theoretical analysis of the obtained experimental data allows us to evaluate the exciton fine structure parameters, the g-factors, and the spin lifetimes of the bright and dark excitons. The optical alignment effect enables the identification of the exciton and trion contributions to the emission spectrum, even in the absence of their clear separation in the spectra.
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Affiliation(s)
- Olga O. Smirnova
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Ina V. Kalitukha
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - Anna V. Rodina
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | | | - Victor F. Sapega
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Olga S. Ken
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | | | - Nikolai V. Kozyrev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Sergey V. Nekrasov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Yuri G. Kusrayev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Dmitri R. Yakovlev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - Benoit Dubertret
- Laboratoire de Physique et d’Étude des Matériaux, ESPCI, CNRS, 75231 Paris, France
| | - Manfred Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
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2
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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: 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.
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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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3
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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.
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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.
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4
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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.
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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
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5
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Kotova LV, Rakhlin MV, Galimov AI, Eliseyev IA, Borodin BR, Platonov AV, Kirilenko DA, Poshakinskiy AV, Shubina TV. MoS 2 flake as a van der Waals homostructure: luminescence properties and optical anisotropy. NANOSCALE 2021; 13:17566-17575. [PMID: 34661218 DOI: 10.1039/d1nr05439b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigated multilayer plates prepared by exfoliation from a high-quality MoS2 crystal and revealed that they represent a new object - a van der Waals homostructure consisting of a bulk core and a few detached monolayers on its surface. This architecture comprising elements with different electron band structures leads to specific luminescence, when the broad emission band from the core is cut by the absorption peaks of strong exciton resonances in the surface monolayers. The exfoliated flakes exhibit strong optical anisotropy. We have observed linear to circular polarization conversion that reaches 15% for normally incident light in transmission geometry. This background effect is due to the fluctuations of the c axis relative to the normal, whereas the pronounced resonance contribution is explained by the polarization anisotropy of the excitons localized in the stripes of the dissected surface monolayers.
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6
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Hinterding SM, Salzmann BBV, Vonk SJW, Vanmaekelbergh D, Weckhuysen BM, Hutter EM, Rabouw FT. Single Trap States in Single CdSe Nanoplatelets. ACS NANO 2021; 15:7216-7225. [PMID: 33759503 PMCID: PMC8155320 DOI: 10.1021/acsnano.1c00481] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Trap states can strongly affect semiconductor nanocrystals, by quenching, delaying, and spectrally shifting the photoluminescence (PL). Trap states have proven elusive and difficult to study in detail at the ensemble level, let alone in the single-trap regime. CdSe nanoplatelets (NPLs) exhibit significant fractions of long-lived "delayed emission" and near-infrared "trap emission". We use these two spectroscopic handles to study trap states at the ensemble and the single-particle level. We find that reversible hole trapping leads to both delayed and trap PL, involving the same trap states. At the single-particle level, reversible trapping induces exponential delayed PL and trap PL, with lifetimes ranging from 40 to 1300 ns. In contrast with exciton PL, single-trap PL is broad and shows spectral diffusion and strictly single-photon emission. Our results highlight the large inhomogeneity of trap states, even at the single-particle level.
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Affiliation(s)
- Stijn
O. M. Hinterding
- Soft
Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Bastiaan B. V. Salzmann
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
| | - Sander J. W. Vonk
- Soft
Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Daniel Vanmaekelbergh
- Condensed
Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
| | - Bert M. Weckhuysen
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Eline M. Hutter
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
| | - Freddy T. Rabouw
- Soft
Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584CC Utrecht, The Netherlands
- Inorganic
Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands
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7
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Hu Z, Kim Y, Krishnamurthy S, Avdeev ID, Nestoklon MO, Singh A, Malko AV, Goupalov SV, Hollingsworth JA, Htoon H. Intrinsic Exciton Photophysics of PbS Quantum Dots Revealed by Low-Temperature Single Nanocrystal Spectroscopy. NANO LETTERS 2019; 19:8519-8525. [PMID: 31714793 DOI: 10.1021/acs.nanolett.9b02937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
With a tunable size-dependent photoluminescence (PL) over a wide infrared wavelength range, lead chalcogenide quantum dots (QDs) have attracted significant scientific and technological interest. Nevertheless, the investigation of intrinsic exciton photophysics at the single-QD level has remained a challenge. Herein, we present a comprehensive study of PL properties for the individual core/shell PbS/CdS QDs emissive near 1.0 eV. In contrast to the sub-meV spectral line widths observed for II/VI QDs, PbS/CdS QDs are predicted to possess broad homogeneous line widths. Performing spectroscopy at cryogenic (4 K) temperatures, we provide direct evidence confirming theoretical predictions, showing that intrinsic line widths for PbS/CdS QDs are in the range of 8-25 meV, with an average of 16.4 meV. In addition, low-temperature, single-QD spectroscopy reveals a broad low-energy side emission attributable to optical as well as localized acoustic phonon-assisted transitions. By tracking single QDs from 4 to 250 K, we were able to probe temperature-dependent evolutions of emission energy, line width, and line shape. Finally, polarization-resolved PL imaging showed that PbS/CdS QDs are characterized by a 3D emission dipole, in contrast with the 2D dipole observed for CdSe QDs.
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Affiliation(s)
- Zhongjian Hu
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Younghee Kim
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Sachidananda Krishnamurthy
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
- Department of Physics , The University of Texas at Dallas , Richardson , Texas 75080 , United States
| | | | | | - Ajay Singh
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Anton V Malko
- Department of Physics , The University of Texas at Dallas , Richardson , Texas 75080 , United States
| | - Serguei V Goupalov
- Ioffe Institute , 194021 St. Petersburg , Russia
- Department of Physics , Jackson State University , Jackson , Mississippi 39217 , United States
| | - Jennifer A Hollingsworth
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
| | - Han Htoon
- Center for Integrated Nanotechnologies, Material Physics and Applications Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , United States
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8
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Pandya R, Steinmetz V, Puttisong Y, Dufour M, Chen WM, Chen RYS, Barisien T, Sharma A, Lakhwani G, Mitioglu A, Christianen PCM, Legrand L, Bernardot F, Testelin C, Chin AW, Ithurria S, Chamarro M, Rao A. Fine Structure and Spin Dynamics of Linearly Polarized Indirect Excitons in Two-Dimensional CdSe/CdTe Colloidal Heterostructures. ACS NANO 2019; 13:10140-10153. [PMID: 31490653 DOI: 10.1021/acsnano.9b03252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Heterostructured two-dimensional colloidal nanoplatelets are a class of material that has attracted great interest for optoelectronic applications due to their high photoluminescence yield, atomically tunable thickness, and ultralow lasing thresholds. Of particular interest are laterally heterostructured core-crown nanoplatelets with a type-II band alignment, where the in-plane spatial separation of carriers leads to indirect (or charge transfer) excitons with long lifetimes and bright, highly Stokes shifted emission. Despite this, little is known about the nature of the lowest energy exciton states responsible for emission in these materials. Here, using polarization-controlled, steady-state, and time-resolved photoluminescence measurements, at temperatures down to 1.6 K and magnetic fields up to 30 T, we study the exciton fine structure and spin dynamics of archetypal type-II CdSe/CdTe core-crown nanoplatelets. Complemented by theoretical modeling and zero-field quantum beat measurements, we find the bright-exciton fine structure consists of two linearly polarized states with a fine structure splitting ∼50 μeV and an indirect exciton Landé g-factor of 0.7. In addition, we show the exciton spin lifetime to be in the microsecond range with an unusual B-3 magnetic field dependence. The discovery of linearly polarized exciton states and emission highlights the potential for use of such materials in display and imaging applications without polarization filters. Furthermore, the small exciton fine structure splitting and a long spin lifetime are fundamental advantages when envisaging CdSe/CdTe nanoplatelets as elementary bricks for the next generation of quantum devices, particularly given their ease of fabrication.
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Affiliation(s)
- Raj Pandya
- Cavendish Laboratory , University of Cambridge , J.J. Thomson Avenue , CB3 0HE Cambridge , United Kingdom
| | - Violette Steinmetz
- Sorbonne Université CNRS-UMR 7588, Institut des NanoSciences de Paris , INSP, 4 place Jussieu , F-75005 Paris , France
| | - Yuttapoom Puttisong
- Functional Electronic Materials, Department of Physics, Chemistry and Biology , Linköping University , 58183 Linköping , Sweden
| | - Marion Dufour
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris , PSL Research University, CNRS , 10 rue Vauquelin , 75005 Paris , France
| | - Weimin M Chen
- Functional Electronic Materials, Department of Physics, Chemistry and Biology , Linköping University , 58183 Linköping , Sweden
| | - Richard Y S Chen
- Cavendish Laboratory , University of Cambridge , J.J. Thomson Avenue , CB3 0HE Cambridge , United Kingdom
| | - Thierry Barisien
- Sorbonne Université CNRS-UMR 7588, Institut des NanoSciences de Paris , INSP, 4 place Jussieu , F-75005 Paris , France
| | - Ashish Sharma
- ARC Centre of Excellence in Exciton Science, School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Girish Lakhwani
- ARC Centre of Excellence in Exciton Science, School of Chemistry , The University of Sydney , Sydney , New South Wales 2006 , Australia
| | - Anatolie Mitioglu
- High Field Magnet Laboratory (HFML - EMFL) , Radboud University , 6525 ED Nijmegen , The Netherlands
| | - Peter C M Christianen
- High Field Magnet Laboratory (HFML - EMFL) , Radboud University , 6525 ED Nijmegen , The Netherlands
| | - Laurent Legrand
- Sorbonne Université CNRS-UMR 7588, Institut des NanoSciences de Paris , INSP, 4 place Jussieu , F-75005 Paris , France
| | - Frédérick Bernardot
- Sorbonne Université CNRS-UMR 7588, Institut des NanoSciences de Paris , INSP, 4 place Jussieu , F-75005 Paris , France
| | - Christophe Testelin
- Sorbonne Université CNRS-UMR 7588, Institut des NanoSciences de Paris , INSP, 4 place Jussieu , F-75005 Paris , France
| | - Alex W Chin
- Sorbonne Université CNRS-UMR 7588, Institut des NanoSciences de Paris , INSP, 4 place Jussieu , F-75005 Paris , France
| | - Sandrine Ithurria
- Laboratoire de Physique et d'Etude des Matériaux, ESPCI Paris , PSL Research University, CNRS , 10 rue Vauquelin , 75005 Paris , France
| | - Maria Chamarro
- Sorbonne Université CNRS-UMR 7588, Institut des NanoSciences de Paris , INSP, 4 place Jussieu , F-75005 Paris , France
| | - Akshay Rao
- Cavendish Laboratory , University of Cambridge , J.J. Thomson Avenue , CB3 0HE Cambridge , United Kingdom
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