Electronic, optical and photocatalytic properties of fully hydrogenated GeC monolayer

Abstract

In this work, we study the electronic, optical, and photocatalytic properties of fully hydrogenated GeC monolayer under strain engineering and external electric field using first-principles investigations. Our calculations demonstrate that at the equilibrium state, fully hydrogenated GeC monolayer is a indirect-semiconductor with band gap of 3.493 eV and it possesses photocatalytic characteristics for water splitting and in particular, photocatalytic activities can be enhanced by a negative electric field under ultraviolet light. We can control the band gap of fully hydrogenated GeC monolayer by biaxial strain or external electric field and semiconductor–metal phase transition happens at certain elongation of biaxial strain. Compared to pure monolayer GeC, the fully hydrogenation causes optical absorption peaks of GeC shifting to a higher energy region. While the optical spectra of the fully hydrogenated GeC monolayer are strongly dependent on the strain, the effect of the electric field on them is negligible. Our findings can provide useful information for the applicability of fully hydrogenated GeC monolayer in nanoelectronic devices and photocatalytic water splitting. • Fully hydrogenated GeC monolayer is a semiconductor with indirect bandgap of 3.493 eV. • Semiconductor–metal phase transition happens in H–GeC–H at certain elongation of biaxial strain. • Full hydrogenation causes optical absorption peaks of GeC shifting to a higher energy region. • H–GeC–H possesses photocatalytic characteristics for water splitting at equilibrium. • Photocatalytic activities in H–GeC–H can be enhanced by a negative electric field under ultraviolet light.