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Tan J, Li D, Zhu J, Han N, Gong Y, Zhang Y. Self-trapped excitons in soft semiconductors. NANOSCALE 2022; 14:16394-16414. [PMID: 36317508 DOI: 10.1039/d2nr03935d] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Self-trapped excitons (STEs) have attracted tremendous attention due to their intriguing properties and potential optoelectronic applications. STEs are formed from the lattice distortion induced by the strong electron (exciton)-phonon coupling in soft semiconductors upon photoexcitation, which features in broadband photoluminescence (PL) emission spectra with a large Stokes shift. Recently, significant progress has been achieved in this field but many remain challenges that need to be solved, including the understanding of the underlying physical mechanism, tuning of the performance, and device applications. Along these lines, for the first time, systematic experimental characterizations and advanced theoretical calculations are presented in this review to shed light on the physical mechanism. The possibility of tuning the STEs through multiple degrees of freedom is also presented, along with an overview of the STE-based emerged applications and future research perspectives.
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Affiliation(s)
- Jianbin Tan
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, P.R. China.
| | - Delong Li
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, P.R. China.
| | - Jiaqi Zhu
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, P.R. China.
| | - Na Han
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, P.R. China.
| | - Youning Gong
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, P.R. China.
| | - Yupeng Zhang
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, P.R. China.
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Yu J, Kong J, Hao W, Guo X, He H, Leow WR, Liu Z, Cai P, Qian G, Li S, Chen X, Chen X. Broadband Extrinsic Self-Trapped Exciton Emission in Sn-Doped 2D Lead-Halide Perovskites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806385. [PMID: 30556251 DOI: 10.1002/adma.201806385] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/07/2018] [Indexed: 06/09/2023]
Abstract
As emerging efficient emitters, metal-halide perovskites offer the intriguing potential to the low-cost light emitting devices. However, semiconductors generally suffer from severe luminescence quenching due to insufficient confinement of excitons (bound electron-hole pairs). Here, Sn-triggered extrinsic self-trapping of excitons in bulk 2D perovskite crystal, PEA2 PbI4 (PEA = phenylethylammonium), is reported, where exciton self-trapping never occurs in its pure state. By creating local potential wells, isoelectronic Sn dopants initiate the localization of excitons, which would further induce the large lattice deformation around the impurities to accommodate the self-trapped excitons. With such self-trapped states, the Sn-doped perovskites generate broadband red-to-near-infrared (NIR) emission at room temperature due to strong exciton-phonon coupling, with a remarkable quantum yield increase from 0.7% to 6.0% (8.6 folds), reaching 42.3% under a 100 mW cm-2 excitation by extrapolation. The quantum yield enhancement stems from substantial higher thermal quench activation energy of self-trapped excitons than that of free excitons (120 vs 35 meV). It is further revealed that the fast exciton diffusion involves in the initial energy transfer step by transient absorption spectroscopy. This dopant-induced extrinsic exciton self-trapping approach paves the way for extending the spectral range of perovskite emitters, and may find emerging application in efficient supercontinuum sources.
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Affiliation(s)
- Jiancan Yu
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
| | - Jintao Kong
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
| | - Wei Hao
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
| | - Xintong Guo
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
| | - Huajun He
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Wan Ru Leow
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
| | - Zhiyuan Liu
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
| | - Pingqiang Cai
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
| | - Guodong Qian
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Shuzhou Li
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
| | - Xueyuan Chen
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, China
| | - Xiaodong Chen
- Innovative Centre for Flexible Devices (iFLEX), School of Materials Science and Engineering, Nanyang Technological University Singapore, Singapore, 639798, Singapore
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Sellers IR, Whiteside VR, Kuskovsky IL, Govorov AO, McCombe BD. Aharonov-Bohm excitons at elevated temperatures in type-II ZnTe/ZnSe quantum dots. PHYSICAL REVIEW LETTERS 2008; 100:136405. [PMID: 18517978 DOI: 10.1103/physrevlett.100.136405] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Revised: 02/13/2008] [Indexed: 05/26/2023]
Abstract
Optical emission from type-II ZnTe/ZnSe quantum dots demonstrates large and persistent oscillations in both the peak energy and intensity indicating the formation of coherently rotating states. Furthermore, these Aharonov-Bohm oscillations are shown to be remarkably robust and persist until 180 K. This is at least one order of magnitude greater than the typical temperatures in lithographically defined rings. To our knowledge, this is the highest temperature at which the AB effect has been observed in solid-state and molecular nanostructures.
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Affiliation(s)
- I R Sellers
- Department of Physics, Fronczak Hall, University at Buffalo SUNY, Buffalo, New York 14260, USA.
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Wang PD, Ledentsov NN, Yassievich IN, Pakhomov A, Egovov AY, Kop'ev PS, Ustinov VM. Magneto-optical properties in ultrathin InAs-GaAs quantum wells. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:1604-1610. [PMID: 9976345 DOI: 10.1103/physrevb.50.1604] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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