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Zhang L, Wang S, Jiang Y, Yuan M. Stable and Efficient Mixed-halide Perovskite LEDs. CHEMSUSCHEM 2024; 17:e202301205. [PMID: 38081803 DOI: 10.1002/cssc.202301205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/08/2023] [Indexed: 01/12/2024]
Abstract
Tailoring bandgap by mixed-halide strategy in perovskites has attracted extraordinary attention due to the flexibility of halide ion combinations and has emerged as the most direct and effective approach to precisely tune the emission wavelength throughout the entire visible light spectrum. Mixed-halide perovskites, yet, still suffered from several problems, particularly phase segregation under external stimuli because of ions migration. Understanding the essential cause and finding sound strategies, thus, remains a challenge for stable and efficient mixed-halide perovskite light-emitting diodes (PeLEDs). The review herein presents an overview of the diverse application scenarios and the profound significance associated with mixed-halide perovskites. We then summarize the challenges and potential research directions toward developing high stable and efficient mixed-halide PeLEDs. The review thus provides a systematic and timely summary for the community to deepen the understanding of mixed-halide perovskite materials and resulting PeLEDs.
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Affiliation(s)
- Li Zhang
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Stor1age Center (RECAST), College of Chemistry, Nankai University, Tianjin, P. R. China
| | - Saike Wang
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Stor1age Center (RECAST), College of Chemistry, Nankai University, Tianjin, P. R. China
| | - Yuanzhi Jiang
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Stor1age Center (RECAST), College of Chemistry, Nankai University, Tianjin, P. R. China
| | - Mingjian Yuan
- Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Stor1age Center (RECAST), College of Chemistry, Nankai University, Tianjin, P. R. China
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2
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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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3
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Athapaththu DV, Kordesch ME, Chen J. Monitoring Phase Separation and Dark Recovery in Mixed Halide Perovskite Clusters and Single Crystals Using In Situ Spectromicroscopy. J Phys Chem Lett 2024; 15:1105-1111. [PMID: 38262449 PMCID: PMC10877542 DOI: 10.1021/acs.jpclett.3c03280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Mixed halide perovskites (MHPs) are a group of semiconducting materials with promising applications in optoelectronics and photovoltaics, whose bandgap can be altered by adjusting the halide composition. However, the current challenge is to stabilize the light-induced halide separation, which undermines the device's performance. Herein we track down the phase separation dynamics of CsPbBr1.2I1.8 MHP single cubic nanocrystals (NCs) and clusters as a function of time by in situ fluorescence spectromicroscopy. The particles were sorted into groups 1 and 2 using initial photoluminescence intensities. The phase separation followed by recovery kinetics under dark and photo blinking analysis suggests that group 1 behaved more like single NCs and group 2 behaved like clusters. Under the 0.64 W/cm2 laser illumination, the phase shifts for single NCs are 3.4 ± 1.9 nm. The phase shifts are linearly correlated with the initial photoluminescence intensities of clusters, suggesting possible interparticle halide transportation.
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Affiliation(s)
- Deepani V. Athapaththu
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
- Nanoscale & Quantum Phenomena Institute, Ohio University, Athens, OH 45701, USA
| | - Martin E. Kordesch
- Department of Physics and Astronomy, Ohio University, Athens, OH 45701, USA
- Nanoscale & Quantum Phenomena Institute, Ohio University, Athens, OH 45701, USA
| | - Jixin Chen
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
- Nanoscale & Quantum Phenomena Institute, Ohio University, Athens, OH 45701, USA
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4
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Liu X, Luo D, Lu ZH, Yun JS, Saliba M, Seok SI, Zhang W. Stabilization of photoactive phases for perovskite photovoltaics. Nat Rev Chem 2023; 7:462-479. [PMID: 37414982 DOI: 10.1038/s41570-023-00492-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2023] [Indexed: 07/08/2023]
Abstract
Interest in photovoltaics (PVs) based on Earth-abundant halide perovskites has increased markedly in recent years owing to the remarkable properties of these materials and their suitability for energy-efficient and scalable solution processing. Formamidinium lead triiodide (FAPbI3)-rich perovskite absorbers have emerged as the frontrunners for commercialization, but commercial success is reliant on the stability meeting the highest industrial standards and the photoactive FAPbI3 phase suffers from instabilities that lead to degradation - an effect that is accelerated under working conditions. Here, we critically assess the current understanding of these phase instabilities and summarize the approaches for stabilizing the desired phases, covering aspects from fundamental research to device engineering. We subsequently analyse the remaining challenges for state-of-the-art perovskite PVs and demonstrate the opportunities to enhance phase stability with ongoing materials discovery and in operando analysis. Finally, we propose future directions towards upscaling perovskite modules, multijunction PVs and other potential applications.
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Affiliation(s)
- Xueping Liu
- Advanced Technology Institute, University of Surrey, Guildford, UK
| | - Deying Luo
- Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario, Canada.
| | - Zheng-Hong Lu
- Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Jae Sung Yun
- Advanced Technology Institute, University of Surrey, Guildford, UK
| | - Michael Saliba
- Institute for Photovoltaics (IPV), University of Stuttgart, Stuttgart, Germany.
- Helmholtz Young Investigator Group FRONTRUNNER, IEK5-Photovoltaik, Forschungszentrum Jülich, Jülich, Germany.
| | - Sang Il Seok
- Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea.
| | - Wei Zhang
- Advanced Technology Institute, University of Surrey, Guildford, UK.
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5
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Gao X, Wang H, Dong H, Shao J, Shao Y, Zhang L. Tunable Key-Size Physical Unclonable Functions Based on Phase Segregation in Mixed Halide Perovskites. ACS APPLIED MATERIALS & INTERFACES 2023; 15:23429-23438. [PMID: 37140137 DOI: 10.1021/acsami.3c02193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Optical physical unclonable functions (PUFs) have been considered as an effective tool for anti-counterfeiting owing to the uncontrollable manufacturing process and excellent resistance to machine-learning attacks. However, most optical PUFs exhibit fixed challenge-response pairs and static encoding structures after they are manufactured, which significantly impedes the actual development. Herein, we propose a tunable key-size PUF based on reversible phase segregation in mixed halide perovskites with uncontrollable Br/I ratios under variable power densities. The basic performance of encryption keys of low and high power density was evaluated and indicated a high degree of uniformity, uniqueness, and readout repeatability. Merging the binary keys of low and high power density, tunable key-size PUF is realized with higher security. The proposed tunable key-size PUF offers new insights into the development of dynamic-structure PUFs and demonstrates a novel scheme for achieving higher security of anti-counterfeiting and authentication.
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Affiliation(s)
- Xinyu Gao
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800 Shanghai, China
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024 Hangzhou, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Hu Wang
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800 Shanghai, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Hongxing Dong
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800 Shanghai, China
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024 Hangzhou, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Jianda Shao
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800 Shanghai, China
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024 Hangzhou, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Yuchuan Shao
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800 Shanghai, China
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024 Hangzhou, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Long Zhang
- Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 201800 Shanghai, China
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 310024 Hangzhou, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, 100049 Beijing, China
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6
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Wright AD, Patel JB, Johnston MB, Herz LM. Temperature-Dependent Reversal of Phase Segregation in Mixed-Halide Perovskites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2210834. [PMID: 36821796 DOI: 10.1002/adma.202210834] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/24/2023] [Indexed: 05/12/2023]
Abstract
Understanding the mechanism of light-induced halide segregation in mixed-halide perovskites is essential for their application in multijunction solar cells. Here, photoluminescence spectroscopy is used to uncover how both increases in temperature and light intensity can counteract the halide segregation process. It is observed that, with increasing temperature, halide segregation in CH3 NH3 Pb(Br0.4 I0.6 )3 first accelerates toward ≈290 K, before slowing down again toward higher temperatures. Such reversal is attributed to the trade-off between the temperature activation of segregation, for example through enhanced ionic migration, and its inhibition by entropic factors. High light intensities meanwhile can also reverse halide segregation; however, this is found to be only a transient process that abates on the time scale of minutes. Overall, these observations pave the way for a more complete model of halide segregation and aid the development of highly efficient and stable perovskite multijunction and concentrator photovoltaics.
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Affiliation(s)
- Adam D Wright
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Jay B Patel
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Michael B Johnston
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Laura M Herz
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
- Institute for Advanced Study, Technical University of Munich (TUM), Lichtenbergstraße 2a, 85748, Garching bei München, Germany
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7
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Zheng R, Ueda J, Shinozaki K, Tanabe S. Reversible Phase Segregation and Amorphization of Mixed-Halide Perovskite Nanocrystals in Glass Matrices. J Phys Chem Lett 2022; 13:7809-7815. [PMID: 35975956 DOI: 10.1021/acs.jpclett.2c02261] [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
Mixed-halide perovskites have attracted great attention in applications of lighting and photovoltaic devices due to their excellent properties. Understanding the phase segregation mechanism of mixed-halide perovskite has significance for suppressing the performance degradation of optoelectronic devices. Herein, we investigate the mixed-halide perovskite nanocrystals (NCs) in isolation from the external factors (oxygen, moisture, and pressure) using glass encapsulation, which shows excellent photostability against phase segregation. By monitoring the structural evolution of the NCs in glass matrices, the coexisting phase segregation and amorphization of mixed-halide perovskites are observed in real-time. The results show that thermal-induced local temperature increase plays a dominant role in the phase segregation of mixed-halide perovskite NCs. The recovery process is driven by the spontaneous crystallization of the amorphous mixed-halide phase. The clarified dynamic equilibrium process between the compositional segregation (mixing) and structural disorder (order) gives us a better insight into the reversible phase segregation mechanism of mixed-halide perovskite.
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Affiliation(s)
- Ruilin Zheng
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Jumpei Ueda
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
- School of Material Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| | - Kenji Shinozaki
- National Institute of Advanced Industrial Science and Technology, Osaka 563-8577, Japan
- Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Setsuhisa Tanabe
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
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8
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Bernhardt A, Ambagaspitiya TD, Kordesch ME, Cimatu KLA, Chen J. In-situ ellipsometry measurements on the halide phase segregation of mixed halide lead perovskites. Chemphyschem 2022; 23:e202200022. [PMID: 35472252 PMCID: PMC9401859 DOI: 10.1002/cphc.202200022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/19/2022] [Indexed: 11/08/2022]
Abstract
Methylammonium lead iodide bromides MAPb(BrxI1‐x)3 are a class of mixed halide lead perovskites, materials that offer high‐power conversion efficiencies and bandgap tunability. For these reasons, they are a promising absorber material for future solar cells, although their use is still limited due to several factors. The reversible phase segregation under even low light intensities is one of them, lowering the effective bandgap due to local segregation into iodide‐rich and bromide‐rich phases. While several studies have been done to illuminate the mechanism and suppression of phase segregation, challenges remain to understand its kinetics. We obtained dynamic ellipsometric measurements from x=0.5 mixed halide lead perovskite thin films protected by a polystyrene layer under green laser light with a power density of ∼11 W/cm2. Time constants between 1.7(±0.7)×10−3 s−1 for the segregation and 1.5(±0.6)×10−4 s−1 for recovery were calculated. The phase segregation rate constants are surprisingly two orders of magnitude slower than and the recovery rate is consistent with those measured using photoluminescence methods under similar conditions. These results confirm a concern in the literature about the complexity in the phase separation kinetics measured from photoluminescence. We expect ellipsometry to serve as a complementary technique to other spectroscopies in studying mixed‐halide lead perovskites phase segregation in the future.
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Affiliation(s)
- Annik Bernhardt
- Ohio University, Chemistry and Biochemistry, 133 University Terrace, 45701, Athens, UNITED STATES
| | - Tharushi D Ambagaspitiya
- Ohio University, Department of Chemistry and Biochemistry, 133 University Terrace, 45701, Athens, UNITED STATES
| | - Martin E Kordesch
- Ohio University, Department of Physics and Astronomy, 100 University Terrace, 45701, Athens, UNITED STATES
| | - Katherine Leslee A Cimatu
- Ohio University, Department of Chemistry and Biochemistry, 133 University Terrace, 45701, Athens, UNITED STATES
| | - Jixin Chen
- Ohio University, Department of Chemistry and Biochemistry, 100 University Terrace, 45701, Athens, UNITED STATES
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9
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Abstract
Photoinduced halide segregation in mixed halide perovskites is an intriguing phenomenon and simultaneously a stability issue. In-depth probing this effect and unveiling the underpinning mechanisms are of great interest and significance. This article reviews the progress in visualized investigation of halide segregation, especially light-induced, by means of spatially-resolved imaging techniques. Furthermore, the current understanding of photoinduced phase separation based on several possible mechanisms is summarized and discussed. Finally, the remained open questions and future outlook in this field are outlined.
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10
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Halford GC, Deng Q, Gomez A, Green T, Mankoff JM, Belisle RA. Structural Dynamics of Metal Halide Perovskites during Photoinduced Halide Segregation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:4335-4343. [PMID: 35023337 DOI: 10.1021/acsami.1c22854] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Despite substantial research effort, photoinduced halide segregation in mixed halide perovskites continues to limit the available perovskite chemistries for use in optoelectronic applications. In this study, we present new insights into halide-segregation process through in situ X-ray diffraction measurements that reveal substantial structural changes in mixed-halide perovskites under excitation. We observe that photoinduced halide segregation leads to the formation of one iodide-rich and one bromide-rich perovskite composition whose Br:I ratios are the same (at 20 and 93% bromine, respectively), for a range of compositions of the pristine initial perovskite phase. This segregation reverses in the dark to re-form a mixed halide perovskite with the same lattice spacing as the pristine perovskite. From these results, we determine a kinetic rate for the formation and dissolution of these new crystalline phases and observe that the crystalline orientation is preserved through the light-segregation and dark-relaxation processes. Our results are consistent with a model of halide segregation where excitation causes changes in the free energy of mixing and ultimately the formation of a miscibility gap in the MAPb(IxBr1-x)3 phase diagram and should inform future works to model and manipulate the halide-segregation process in mixed-halide perovskites.
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Affiliation(s)
- Gabriel C Halford
- Chemistry Department, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Qingmu Deng
- Olin College of Engineering, Needham, Massachusetts 02492, United States
| | - Annie Gomez
- Physics Department, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Tianna Green
- Physics Department, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Jill M Mankoff
- Chemistry Department, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Rebecca A Belisle
- Physics Department, Wellesley College, Wellesley, Massachusetts 02481, United States
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11
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Vicente JR, Kordesch ME, Chen J. Stabilization of Mixed-Halide Lead Perovskites Under Light by Photothermal Effects. JOURNAL OF ENERGY CHEMISTRY 2021; 63:8-11. [PMID: 35450060 PMCID: PMC9017715 DOI: 10.1016/j.jechem.2021.08.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mixed-halide lead perovskites (MHLPs) are semiconductor materials with bandgaps that are tunable across the visible spectrum and have seen promising applications in photovoltaics and optoelectronics. However, their segregation into phases with enriched halide components, under resonant light illumination and/or electric field, have hindered their practical applications. Herein, we demonstrate the stabilization of the MHLP photoluminescence (PL) peak as a function of their excitation intensities. This effect is associated with the phase segregation of MHLPs and their subsequent remixing by photothermal heating. We conclude that the balance between these opposing processes dictates the equilibrium PL peak of the MHLPs. The findings in this work could serve as a potential approach to obtain MHLP with stable emission peaks under operating conditions.
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Affiliation(s)
- Juvinch R. Vicente
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
- Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701, USA
- Department of Chemistry, University of the Philippines Visayas, Miagao, Iloilo 5023, Philippines
| | - Martin E. Kordesch
- Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701, USA
- Department of Physics and Astronomy, Ohio University, Athens, OH 45701, USA
| | - Jixin Chen
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA
- Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701, USA
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12
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DuBose JT, Mathew PS, Cho J, Kuno M, Kamat PV. Modulation of Photoinduced Iodine Expulsion in Mixed Halide Perovskites with Electrochemical Bias. J Phys Chem Lett 2021; 12:2615-2621. [PMID: 33689371 DOI: 10.1021/acs.jpclett.1c00367] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Hole trapping at iodine (I) sites in MAPbBr1.5I1.5 mixed halide perovskites (MHP) is responsible for iodine migration and its eventual expulsion into solution. We have now modulated the photoinduced iodine expulsion in MHP through an externally applied electrochemical bias. At positive potentials, electron extraction at TiO2/MHP interfaces becomes efficient, leading to hole buildup within MHP films. This improved charge separation, in turn, favors iodine migration as evident from the increased apparent rate constant of iodine expulsion (kexpulsion = 0.0030 s-1). Conversely, at negative potentials (-0.3 V vs Ag/AgCl) electron-hole recombination is facilitated within MHP, slowing down iodine expulsion by an order of magnitude (kexpulsion = 0.00018 s-1). The tuning of the EFermi level through external bias modulates electron extraction at the TiO2/MHP interface and indirectly controls the buildup of holes, ultimately inducing iodine migration/expulsion. Suppressing iodine migration in perovskite solar cells is important for attaining greater stability since they operate under internal electrical bias.
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13
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Cho J, DuBose JT, Mathew PS, Kamat PV. Electrochemically induced iodine migration in mixed halide perovskites: suppression through chloride insertion. Chem Commun (Camb) 2021; 57:235-238. [PMID: 33305300 DOI: 10.1039/d0cc06217k] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The role of chloride in improving the stability of mixed halide perovskites (MAPbClxBr0.5(1-x)I0.5(1-x))3 is probed using spectroelectrochemistry. The injection of holes into mixed halide perovskite films through applied anodic bias results in the selective migration of iodine with ultimate expulsion into the electrolyte. Increasing the Cl content (x = 0 to 0.1) in the mixed halide perovskite suppresses the iodine mobility and thus decreases the rate of its expulsion into the solution. Implications of iodine mobility induced by hole accumulation and its impact on overall stability is discussed.
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Affiliation(s)
- Junsang Cho
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA.
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14
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Chen W, Gan Z, Green MA, Jia B, Wen X. Revealing Dynamic Effects of Mobile Ions in Halide Perovskite Solar Cells Using Time-Resolved Microspectroscopy. SMALL METHODS 2021; 5:e2000731. [PMID: 34927806 DOI: 10.1002/smtd.202000731] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/21/2020] [Indexed: 06/14/2023]
Abstract
Halide perovskites are promising candidate materials for the next generation high-efficiency optoelectronic devices. Since perovskites are electronic-ionic mixed conductors, ion dynamics have a critical impact on the performance and stability of perovskite-based applications. However, comprehensively understanding ionic dynamics is challenging, particularly on nanoscale imaging of ionic dynamics in perovskites. In this review, mobile ion dynamics in halide perovskites investigated via luminescence spectroscopy combined with confocal microscopy are discussed, including mobile ion induced fluorescence quenching, phase segregation in mixed halide hybrid perovskite, and mobile ion accumulation at the interface in perovskite devices. Steady-state and time-resolved luminescence imaging techniques, combined with confocal microscopy, are unique tools for probing ionic dynamics in perovskites, providing invaluable insights on ionic dynamics in nanoscale resolution, along with a wide temporal range from picoseconds to hours. The works in this review are not only for understanding mobile ions to improve the design of perovskite-based devices but also foster the development of microspectroscopic methodologies in a broader solid-state physics context of investigating ionic transports in polycrystalline materials.
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Affiliation(s)
- Weijian Chen
- Centre for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
- Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, University of New South Wales (UNSW), Kensington, NSW, 2052, Australia
| | - Zhixing Gan
- Center for Future Optoelectronic Functional Materials, School of Computer and Electronic Information/School of Artificial Intelligence, Nanjing Normal University, Nanjing, 210023, P. R. China
- College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao, 266042, P. R. China
| | - Martin A Green
- Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, University of New South Wales (UNSW), Kensington, NSW, 2052, Australia
| | - Baohua Jia
- Centre for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
| | - Xiaoming Wen
- Centre for Translational Atomaterials, Swinburne University of Technology, Hawthorn, VIC, 3122, Australia
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