Study on the photoelectric properties of series heterojunctions based on g-GaN

Abstract

The series heterojunctions such as the GeC/GaN, SiC/GaN, and ZnO/GaN heterojunctions, MoS₂/GaN, MoSe₂/GaN, MoSSe/GaN, WS₂/GaN, WSe₂/GaN, and WSSe/GaN heterojunctions are designed and systematically researched based on first-principles calculations, and the electronic properties and photocurrent characteristics are studied in this paper. The results indicate that the band gaps of the heterojunctions are larger than those of the individual monolayers, except for the SiC/GaN heterojunction. The results of Crystal Orbital Hamilton Population (COHP) and Integrated COHP reveal the bonding states in each heterojunction, the Ga-N bonds in the atomic structures play a dominant role in stabilizing the heterojunctions. The final photodetector simulation results show that the photocurrent peaks of the MoS₂/GaN, MoSSe/GaN and WSe₂/GaN heterojunctions exceed 0.1$a_0^2$/photon. Notably, the MoSSe/GaN heterojunction exhibits a high Extinction Ratio (8.202) and a remarkable photocurrent peak (2.610$a_0^2$/photon), indicating that the MoSSe/GaN heterojunction is a promising candidate for novel photodetector.