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Yuan J, Hu F, Ju Y, Li S, Zhao H, Zhang C, Gan Z, Xiao M, Wang X. Perovskite Quantum Heterostructure Constructed by Halide Mixing between a Single CsPbI 3 Nanocrystal and an Individual CsPbBr 3 Microplate. J Phys Chem Lett 2024; 15:6763-6770. [PMID: 38912978 DOI: 10.1021/acs.jpclett.4c01312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/25/2024]
Abstract
Ion migration is significantly enhanced in lead-halide perovskites with a soft crystal lattice, which can promote the formation of a heterogeneous interface between two such materials with different halide-anion compositions. Here we have deposited a single CsPbI3 nanocrystal (NC) on top of an individual CsPbBr3 microplate to create a mixed-halide CsPbBrxI3-x (0 < x < 3) NC by means of the anion exchange process. The formation of a CsPbBrxI3-x/CsPbBr3 heterostructure is confirmed by the much-enlarged geometric volume of the CsPbBrxI3-x NC as compared to the original CsPbI3 one, as well as by its capability of receiving photogenerated excitons from the CsPbBr3 microplate with a larger bandgap energy. The quantum nature of this heterostructure is reflected from single-photon emission of the composing CsPbBrxI3-x NC, which can also be bulk-like during phase segregation to demonstrate a red shift in the photoluminescence peak that is opposite to the common trend observed in smaller-sized mixed-halide NCs.
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Affiliation(s)
- Junyang Yuan
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Fengrui Hu
- College of Engineering and Applied Sciences, and MOE Key Laboratory of Intelligent Optical Sensing and Manipulation, Nanjing University, Nanjing 210093, China
| | - Yu Ju
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Si Li
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Hao Zhao
- School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zhixing Gan
- School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Min Xiao
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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Feng S, Ju Y, Duan R, Man Z, Li S, Hu F, Zhang C, Tao S, Zhang W, Xiao M, Wang X. Complete Suppression of Phase Segregation in Mixed-Halide Perovskite Nanocrystals under Periodic Heating. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308032. [PMID: 37994680 DOI: 10.1002/adma.202308032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/18/2023] [Indexed: 11/24/2023]
Abstract
Under continuous light illumination, it is known that localized domains with segregated halide compositions form in semiconducting mixed-halide perovskites, thus severely limiting their optoelectronic applications due to the negative changes in bandgap energies and charge-carrier characteristics. Here mixed-halide perovskite CsPbBr1.2 I1.8 nanocrystals are deposited onto an indium tin oxide substrate, whose temperature can be rapidly changed by ≈10 °C in a few seconds by applying or removing an external voltage. Such a sudden temperature change induces a temporary transition of CsPbBr1.2 I1.8 nanocrystals from the segregated phase to the mixed phase, the latter of which can be permanently maintained when the light illumination is coupled with periodic heating cycles. These findings mark the emergence of a practical solution to the detrimental phase-segregation problem, given that a small temperature modulation is readily available in various fundamental studies and practical devices of mixed-halide perovskites.
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Affiliation(s)
- Shengnan Feng
- School of Physics, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Yu Ju
- School of Physics, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Rentong Duan
- School of Physics, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Zaiqin Man
- College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China
| | - Shuyi Li
- School of Physics, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Fengrui Hu
- College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China
| | - Chunfeng Zhang
- School of Physics, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Shuxia Tao
- Materials Simulation and Modelling, Department of Applied Physics, Eindhoven University of Technology, Eindhoven, 5600 MB, The Netherlands
| | - Weihua Zhang
- College of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China
| | - Min Xiao
- School of Physics, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
| | - Xiaoyong Wang
- School of Physics, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
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Cai R, Wadgaonkar I, Lim JWM, Dal Forno S, Giovanni D, Feng M, Ye S, Battiato M, Sum TC. Zero-field quantum beats and spin decoherence mechanisms in CsPbBr 3 perovskite nanocrystals. Nat Commun 2023; 14:2472. [PMID: 37120626 PMCID: PMC10148794 DOI: 10.1038/s41467-023-37721-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 03/24/2023] [Indexed: 05/01/2023] Open
Abstract
Coherent optical manipulation of exciton states provides a fascinating approach for quantum gating and ultrafast switching. However, their coherence time for incumbent semiconductors is highly susceptible to thermal decoherence and inhomogeneous broadening effects. Here, we uncover zero-field exciton quantum beating and anomalous temperature dependence of the exciton spin lifetimes in CsPbBr3 perovskite nanocrystals (NCs) ensembles. The quantum beating between two exciton fine-structure splitting (FSS) levels enables coherent ultrafast optical control of the excitonic degree of freedom. From the anomalous temperature dependence, we identify and fully parametrize all the regimes of exciton spin depolarization, finding that approaching room temperature, it is dominated by a motional narrowing process governed by the exciton multilevel coherence. Importantly, our results present an unambiguous full physical picture of the complex interplay of the underlying spin decoherence mechanisms. These intrinsic exciton FSS states in perovskite NCs present fresh opportunities for spin-based photonic quantum technologies.
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Affiliation(s)
- Rui Cai
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Indrajit Wadgaonkar
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Jia Wei Melvin Lim
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
- ERI@N, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore
| | - Stefano Dal Forno
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - David Giovanni
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Minjun Feng
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Senyun Ye
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Marco Battiato
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
| | - Tze Chien Sum
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
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Tang Y, Qin Q, Yang H, Feng S, Zhang C, Zhang J, Xiao M, Wang X. Electrical control of biexciton Auger recombination in single CdSe/CdS nanocrystals. NANOSCALE 2022; 14:7674-7681. [PMID: 35548946 DOI: 10.1039/d2nr00305h] [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
The Auger recombination effect is strongly enhanced in semiconductor nanocrystals due to the quantum confinement, and various strategies in chemical synthesis have been employed so far to suppress this nonradiative decay pathway of multiple excitons. Here we apply external electric fields on single CdSe/CdS giant nanocrystals at room temperature, showing that the biexciton Auger and single-exciton radiative rates can be averagely decreased by ∼40 and ∼10%, respectively. In addition to a reduced overlap of the electron-hole wavefunctions, the large decrease of biexciton Auger rate could be contributed by the enhanced exciton-exciton repulsion, while the electron-hole exchange interaction might be weakened to cause the relatively small decrease of the single-exciton radiative rate. The above findings have thus proved that the external electric field can serve as a post-synthetic knob to tune the exciton recombination dynamics in semiconductor nanocrystals towards their efficient applications in various optoelectronic devices.
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Affiliation(s)
- Ying Tang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
| | - Qilin Qin
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
| | - Hongyu Yang
- Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China.
| | - Shengnan Feng
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
| | - Jiayu Zhang
- Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China.
| | - Min Xiao
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
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