Rational design of bismuth-based oxide double-perovskite semiconductors with large band-gap tunability
ORAL
Abstract
Bismuth-based halide double perovskites, such as Cs2AgBiBr6, have emerged as a new class of semiconductors with applications in solar-energy harvesting and optoelectronics. However, these halides suffer from long-term stability issues due to the weak metal-halogen bonds. We have explored Bi-based oxide double perovskites as an alternative class of semiconducting materials. The oxide framework improves stability due to stronger metal-oxygen bonds and the -2 charge of the oxide anion opens a vast cation composition space to tune the electronic structure of the material. We use a combination of high-throughput density-functional-theory calculations and machine learning to screen through the vast composition space of over 29,000 A'A"M'BiO6 hypothetical oxide double perovskites. We predict various stable compounds within the A'A"M'BiO6 composition space, where M' = V, Mo, W, Ta, Nb, Sb,and Te, which can find applications as stand-alone absorbers, absorbers in tandem solar cells and as photocatalysts.
*This work was supported by NSF DMR-1806147.
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Presenters
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Arashdeep Thind
- Institute of Materials Science & Engineering, Washington University in St. Louis
- Institute of Materials Science and Engineering, Washington University in St. Louis
- Institute of Materials Science & Engineering, Washington University, St. Louis