Electronic Structure Modulation of GaAs Nanowires by Surface Modification

Abstract

The electronic structure tailoring of GaAs nanowires through surface modification was investigated by first-principles calculations. The effect of different surface-passivation materials (H, F, Cl, Br, and I) on the electronic structure of the GaAs nanowires was studied. The results show that for different atoms, the tailoring of the electronic structure is mainly determined by their passivation ability. The surface modification tunes the bandgap and also the bandgap types. The electronic structure of the GaAs nanowires was determined by the surface states and the quantum-confinement effect jointly. The amplitude of the bandgap variation on the diameter is different for the GaAs nanowires modified with different materials. Surface modification offers a new way to tailor the bandgap of GaAs nanowires without changing their diameter or crystal structure.