Theoretical evaluation of oxynitride, oxyfluoride and nitrofluoride perovskites with promising photon absorption properties for solar water splitting

TL;DR

This paper uses advanced first-principles computational methods to evaluate the electronic and optical properties of a wide range of ABX$_2$Y perovskites, identifying promising candidates for photocatalytic water splitting.

Contribution

It systematically applies hybrid DFT, G$_0$W$_0$, and DFPT to analyze ABX$_2$Y perovskites, providing insights into their potential as visible-light photocatalysts.

Findings

Perovskites exhibit direct band gaps from 1.6 to 3.3 eV.

Identified BaInO$_2$F, InSnO$_2$N, CsPbO$_2$F, LaNbN$_2$O as promising photocatalysts.

Provided detailed electronic and optical property data for various compositions.

Abstract

Photocatalytic water splitting represents a very promising but at the same time very challenging contribution to a clean and renewable route to produce hydrogen fuel. Developing efficient and cost-effective photocatalysts for water splitting is a growing need. For this purpose, semiconductor photocatalysts have attracted much more attention due to their stability and low manufacturing cost. Here, we have systematically applied several state-of-the-art advanced first-principles-based methodologies, viz., hybrid density functional theory, many-body perturbation theory (G$_0$W$_0$) and density functional perturbation theory (DFPT), to understand the electronic structure properties of ABX$_2$Y perovskites. We have chosen the vast composition space of ABX$_2$Y type perovskites where A and B are cations and X and Y can be nitrogen, oxygen, or fluorine. These perovskites exhibit direct band gaps ranging from 1.6 to 3.3 eV. Further, to evaluate the feasibility of the visible light catalytic performance, we calculate the structural, electronic, and optical properties of ABX$_2$Y perovskites. In addition, from hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) mechanism, BaInO$_2$F, InSnO$_2$N, CsPbO$_2$F and LaNbN$_2$O are found as probable photocatalysts.