High-throughput computational screening of novel MA2Z4-type Janus structures with excellent photovoltaic and photocatalytic properties

Abstract

Two-dimensional (2D) MA₂Z₄-based materials exhibit immense application potential in the fields of photocatalysis and optoelectronics due to their novel properties and interesting behaviors. But the practical applications of these 2D materials are limited by their undesirable recombination of photoexcited electrons and holes, poor optical absorption, low photoelectric conversion efficiency and redox driving force. Herein, we present material screening and design by using high-throughput first-principles calculations to accelerate the discovery of promising photovoltaic and photocatalytic candidates in the MA₂Z₄ family and their Janus structures. First of all, 61 thermodynamically, dynamically, and mechanically stable structures are screened out from 720 candidate structures. Thereafter, 37 of them exhibit semiconductor properties, and 14 of them have high carrier mobility and absorption performance. Moreover, for further application-driven screening, 10 and 2 potential candidates with high photovoltaic conversion efficiencies (PCE) and photocatalytic hydrogen evolution reaction (HER) activities are selected, respectively. Finally, the regulation law and intrinsic mechanism of asymmetric Janus structures on physicochemical properties of MA₂Z₄ are elucidated. We believe that our study will provide a theoretical foundation and innovative insights for the design of novel Janus structures and their applications in the fields of optoelectronics and photocatalysis.