Strain modulation of the electronic, optical and photocatalytic properties of multi-layer SiC-GaN van der Waals heterostructure

Abstract

In this paper, effects of strain on electronic, optical and photocatalytic properties of SiC/GaN heterostructures are researched using first-principles approach. A double-layered Bi-SiC/Bi-GaN heterostructure with type-II band structure is found. Especially, the strain regulation (-4%∼6%) of SiC/GaN vdW heterostructures are studied for the first time. The results indicate that applied tensile strain does not change the type-II energy band arrangement of Bi-SiC/Bi-GaN heterostructure, but significantly reduces its band gap to 0.85 eV with 6% stretching. The 2% stretching satisfies the redox potential of splitting water at PH = 0 and PH = 7. In the Vis-UV region, the light absorption coefficient increases under tensile strain. This study are useful for designing of the SiC/GaN vdW heterostructure as optoelectronic devices and photocatalysts.