Investigating the CsAuX3[X = Cl, Br, I] perovskite materials properties responsible for photovoltaic applications: A first-principles study

Perovskite materials have generated research attention in recent times owing to their potential to be deployed as photovoltaic materials. In this study, an examination of the structural, mechanical, electronic, and optical properties of CsAuX3(X = Cl, Br, andI) perovskite materials was conducted using the Density Functional Theory to determine their suitability in photovoltaic applications. The findings revealed they were both thermodynamically and mechanically stable. The perovskites were also found to be elastically anisotropic. Suitable semiconducting indirect bandgaps of 1.38 eV, 1.17 eV, and 1.07 eV were predicted for CsAuCl3, CsAuBr3, and CsAuI3 respectively using hybrid HSE06 functional. The absorption coefficient decreased from ultraviolet through the visible to the infrared region for all the perovskite materials. The static dielectric constants increased as Cl was replaced with Br and I suggesting improved photovoltaic properties. The effective masses of holes and electrons together with the exciton binding energy were computed to demonstrate the ease of generating electron-hole pair for the studied perovskites. These perovskite materials, based on the findings of this study may be considered as having potential for applications in the photovoltaic industry.