Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility
Mixed halide perovskites can provide optimal bandgaps for tandem solar cells which are key to improved cost-efficiencies, but can still suffer from detrimental illumination-induced phase segregation. Here we employ optical-pump terahertz-probe spectroscopy to investigate the impact of halide segrega...
| Главные авторы: | , , , , , |
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| Формат: | Journal article |
| Язык: | English |
| Опубликовано: |
Springer Nature
2021
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| _version_ | 1826265362246664192 |
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| author | Motti, SG Patel, JB Oliver, RDJ Snaith, HJ Johnston, MB Herz, LM |
| author_facet | Motti, SG Patel, JB Oliver, RDJ Snaith, HJ Johnston, MB Herz, LM |
| author_sort | Motti, SG |
| collection | OXFORD |
| description | Mixed halide perovskites can provide optimal bandgaps for tandem solar cells which are key to improved cost-efficiencies, but can still suffer from detrimental illumination-induced phase segregation. Here we employ optical-pump terahertz-probe spectroscopy to investigate the impact of halide segregation on the charge-carrier dynamics and transport properties of mixed halide perovskite films. We reveal that, surprisingly, halide segregation results in negligible impact to the THz charge-carrier mobilities, and that charge carriers within the I-rich phase are not strongly localised. We further demonstrate enhanced lattice anharmonicity in the segregated I-rich domains, which is likely to support ionic migration. These phonon anharmonicity effects also serve as evidence of a remarkably fast, picosecond charge funnelling into the narrow-bandgap I-rich domains. Our analysis demonstrates how minimal structural transformations during phase segregation have a dramatic effect on the charge-carrier dynamics as a result of charge funnelling. We suggest that because such enhanced recombination is radiative, performance losses may be mitigated by deployment of careful light management strategies in solar cells. |
| first_indexed | 2024-03-06T20:22:30Z |
| format | Journal article |
| id | oxford-uuid:2e4fc582-ff5b-4468-acad-f289ccf3740e |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:22:30Z |
| publishDate | 2021 |
| publisher | Springer Nature |
| record_format | dspace |
| spelling | oxford-uuid:2e4fc582-ff5b-4468-acad-f289ccf3740e2022-03-26T12:48:14ZPhase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobilityJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2e4fc582-ff5b-4468-acad-f289ccf3740eEnglishSymplectic ElementsSpringer Nature2021Motti, SGPatel, JBOliver, RDJSnaith, HJJohnston, MBHerz, LMMixed halide perovskites can provide optimal bandgaps for tandem solar cells which are key to improved cost-efficiencies, but can still suffer from detrimental illumination-induced phase segregation. Here we employ optical-pump terahertz-probe spectroscopy to investigate the impact of halide segregation on the charge-carrier dynamics and transport properties of mixed halide perovskite films. We reveal that, surprisingly, halide segregation results in negligible impact to the THz charge-carrier mobilities, and that charge carriers within the I-rich phase are not strongly localised. We further demonstrate enhanced lattice anharmonicity in the segregated I-rich domains, which is likely to support ionic migration. These phonon anharmonicity effects also serve as evidence of a remarkably fast, picosecond charge funnelling into the narrow-bandgap I-rich domains. Our analysis demonstrates how minimal structural transformations during phase segregation have a dramatic effect on the charge-carrier dynamics as a result of charge funnelling. We suggest that because such enhanced recombination is radiative, performance losses may be mitigated by deployment of careful light management strategies in solar cells. |
| spellingShingle | Motti, SG Patel, JB Oliver, RDJ Snaith, HJ Johnston, MB Herz, LM Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility |
| title | Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility |
| title_full | Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility |
| title_fullStr | Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility |
| title_full_unstemmed | Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility |
| title_short | Phase segregation in mixed-halide perovskites affects charge-carrier dynamics while preserving mobility |
| title_sort | phase segregation in mixed halide perovskites affects charge carrier dynamics while preserving mobility |
| work_keys_str_mv | AT mottisg phasesegregationinmixedhalideperovskitesaffectschargecarrierdynamicswhilepreservingmobility AT pateljb phasesegregationinmixedhalideperovskitesaffectschargecarrierdynamicswhilepreservingmobility AT oliverrdj phasesegregationinmixedhalideperovskitesaffectschargecarrierdynamicswhilepreservingmobility AT snaithhj phasesegregationinmixedhalideperovskitesaffectschargecarrierdynamicswhilepreservingmobility AT johnstonmb phasesegregationinmixedhalideperovskitesaffectschargecarrierdynamicswhilepreservingmobility AT herzlm phasesegregationinmixedhalideperovskitesaffectschargecarrierdynamicswhilepreservingmobility |