Computational discovery of In2XY2 (X, Y = S, Se, and Te; X ≠ Y) monolayers as multifunctional energy conversion materials†
Abstract
Two-dimensional group III chalcogenides have gained global interest on account of their excellent prospects for applications in multifunctional energy conversion. Herein, via density functional theory calculations, we systematically unravel the electronic structures of In2XY2 (X, Y = S, Se, and Te; X ≠ Y) monolayers for their applications in energy conversion areas. Interestingly, the characteristics of the efficient spatial separation of photo-generated charge carriers, suitable band edge positions, and outstanding light-harvesting abilities indicate that In2SSe2, In2STe2, In2SeS2, and In2SeTe2 monolayers are desirable photocatalysts for the overall water splitting. It is found that In2SSe2 and In2STe2 act as donor materials, while In2SeS2 and In2SeTe2 act as acceptor materials in solar cells made of In2SeS2/In2SSe2 and In2STe2/In2SeTe2 heterostructures. It is highlighted that the theoretical power conversion efficiency reached 15.5% and 22.5% for In2SeS2/In2SSe2 and In2STe2/In2SeTe2 heterostructures, respectively. In particular, the ZT value of the In2STe2 monolayer reaches 3.2 at 500 K, indicating its potential as an up-and-coming candidate for next generation thermoelectric materials. The present research will pave the way for the practical applications of In2XY2 monolayers in the field of multifunctional energy conversion.
- This article is part of the themed collection: Journal of Materials Chemistry C HOT Papers