Alloy engineering in mixed Sn–Ge perovskites for photovoltaic application
| Autor: | Jian Xu, Jian-Bo Liu, Baixin Liu, Yu-Qian Zhou |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Deep level Renewable Energy Sustainability and the Environment Photovoltaic system Alloy Energy conversion efficiency 02 engineering and technology General Chemistry engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Chemical physics engineering General Materials Science 0210 nano-technology Electronic band structure |
| Zdroj: | Journal of Materials Chemistry A. 9:6955-6961 |
| ISSN: | 2050-7496 2050-7488 |
| DOI: | 10.1039/d0ta11107d |
| Popis: | Recently, mixed Sn–Ge perovskites have been proposed as promising lead-free candidates in the photovoltaic (PV) field. However, as an important component of mixed Sn–Ge perovskites, the all-inorganic Sn-based perovskites have a dominant defect, SnI (Sn replacing I, anti-site), which induces a deep level in the band structure and limits the power conversion efficiency. Therefore, it is interesting to discover whether SnI and GeI (Ge replacing I, anti-site) can still act as non-radiative recombination centers in mixed Sn–Ge perovskites. Using first-principles calculations, we explored the effects of SnI and GeI in CsGe1−xSnxI3 (x = 0.25, 0.50, and 0.75) on the PV performances. It was shown that both SnI and GeI are benign only in CsGe0.5Sn0.5I3, and we suggest that CsGe0.5Sn0.5I3 is a promising light-absorbing material with benign defects (GeI and SnI), strong light absorption, and small carrier effective masses. Interestingly, the concerted action of alloying on both band edges and defect states was found to result in better defect properties in CsGe0.5Sn0.5I3, and this is different from results of previous studies where the modulation of introducing alloys on defects is mainly caused by regulating the band edges alone. Our work not only provides theoretical guidance for the experimental synthesis of mixed Sn–Ge perovskites with superior PV performances, but it also shows the potential of alloy engineering in regulating defect levels in perovskites. |
| Databáze: | OpenAIRE |
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