Photogalvanic effect in two-dimensional BGe photodetector by vacancy- and substitution-doping

Abstract

In this paper, based on a graphene-like BGe monolayer (Appl. Mater. Interfaces 2021, 13, 29,764–29769), we built the armchair and zigzag photodetectors and studied linear and circular photogalvanic effects (PGEs) in two devices. It was found that the produced photocurrents in the armchair and zigzag BGe photodetectors show the cosine and sine relations on double times of polarized angle for the incident light, respectively. Moreover, the vacancy- and substitution-doping can enlarge the generated PGE in two BGe photodetectors by 10–100 times due to the decreasing of symmetry from D3h to C2v. Furthermore, the armchair and zigzag BGe photodetectors are all polarization-sensitive for their high extinction ratios, which are larger than those of photodetectors based on multiple two-dimensional materials. This work manifests great potential applications of the BGe monolayer on PGE-driven photodetectors in high performance and low energy-consumption optoelectronics and nanoelectronic devices.