Enhancement of photocatalytic activity of a two-dimensional GeH/graphene heterobilayer under visible light

Searching for novel photocatalysts is one of the most important topics in photocatalytic fields. For this purpose, in the present work, the structural, electronic, and optical properties of GeH as well as a GeH/graphene heterointerface are studied based on hybrid density functional calculations including the nonlocal van der Waals correction. Our results show that the strain-engineered GeH monolayer captures a broad range of the solar spectrum. Moreover, photogenerated electron-hole pairs can be efficiently separated in the GeH/graphene heterojunction by formation of a Schottky barrier. Comparing to a pure GeH monolayer, the hybrid GeH/graphene complex displays an enhanced optical absorption in the visible region, suggesting powerful potential in energy and environmental applications.