2D Janus MoSSe/MoGeSiN4 vdW heterostructures for photovoltaic and photocatalysis applications

Photoelectric catalytic and solar cells are two effective ways to solve the global energy shortage and en-vironmental pollution problems. However, low carrier separation efficiency has been becoming a common problem of current photocatalytic water decomposition and solar cells. In this work, both the electronic structures and optical properties of Janus MoSSe/MoGeSiN4 vdW heterostructures were systematically studied by density functional theory. The results show that the Janus MoSSe/MoGeSiN4 vdW hetero-structure with Se/Ge interfacial contact (Se/Ge heterostructure) is a direct band gap semiconductor. Interestingly, for the Se/Ge heterostructure, spatial separation of the photo-generated electrons and holes is expected, due to the conduction band minimum (CBM) and the valence band maximum (VBM) separately locating on the MoGeSiN4 and MoSSe layer. Besides, the Se/Ge heterostructure not only exhibits con-siderable absorption index in the visible light range but also maximum theoretical photoelectric conversion efficiency approaches 26.4 %, which can be furthermore enhanced by varying the layer distance and biaxial strain. The Se/Ge heterostructure shows high carrier mobility, obvious carrier separation, notably visible light absorption and tunable photoelectric properties, making it promising candidates for novel two di-mensional photocatalysis devices and solar cells.(c) 2023 Elsevier B.V. All rights reserved.