Impact of side passivation on the electronic structures and optical properties of GeSe nanobelts

Abstract

The effects of side passivation with different functional groups (H, F and OH) on the electronic and optical properties of GeSe nanobelts (NBs) are investigated using density functional theory. The optimized structures of GeSe NBs are calculated by full optimization method. It is found that with side passivation of the terminators, pristine metallic GeSe NBs can be tuned to be p-typed semiconductors. Further analysis shows that the side terminators causes the shift of electronic bands and the modification of density of states (DOSs) of band edges of GeSe NBs, resulting in different effective masses of charge carriers depending on the terminator types. The study of optical properties of GeSe NBs shows that the main absorption peaks are modulated by side passivation of the terminators, and quantum yields of side passivated GeSe NBs are evidently bigger than those of pristine ones mainly because passivated ones have suitable band gap values. Our calculated results demonstrate that the electronic and optical properties of GeSe NBs can be effectively tuned by side passivation with functional groups.