In the quest for nontoxic and stable perovskites for solar cells, we have conducted a systematic study of the effect of chalcogen content in oxychalcogenide perovskite by using DFT and quasi-particle perturbation theory. We explored the changes in the electronic structure due to the substitution of O atoms in NaNbO3 and NaTaO3 perovskite structures with various chalcogens (S, Se, Te) at different concentrations. Interestingly, the introduction of the chalcogen atoms resulted in a drastic reduction in the electronic band gap, which made some of the compounds fall within the visible range of the solar spectrum. In addition, our analysis of the electronic structure shows that the optical transition becomes direct as a result of the strong hybridization between the orbitals of the transition metal and those of the chalcogen ion, in contrast to the indirect band feature of NaNbO3 and NaTaO3. We identified candidates with a high theoretical solar conversion efficiency that approached the Shockley–Queisser limit, which makes them suitable for thin-film solar cell applications. The present work serves as a guideline for experimental efforts by identifying the chalcogen content that should be targeted during the synthetic route of thermodynamically stable and strongly photoactive absorbers for oxychalcogenide perovskites in thin-film solar cells.
|Original language||English (US)|
|Number of pages||12|
|State||Published - Nov 16 2017|
Bibliographical noteKAUST Repository Item: Exported on 2022-06-03
Acknowledgements: This work was sponsored by the Qatar Environment and Energy Research Institute (F.E., F.H.A., and N.T.). Computational resources were provided by the research computing group at Texas A&M University at Qatar. We are grateful to SHAHEEN Supercomputer at King Abdullah University of Science and Technology (KAUST), Saudi Arabia, where some of the calculations were conducted. This work was supported by the Qatar National Research Fund (QNRF) through the National Priorities Research Program (NPRP8-090-2-047).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry