Enhanced photogalvanic effect in MoSSe monolayer with grain boundaries

Abstract

The photogalvanic effect (PGE) in two-dimensional materials has emerged as a fascinating mechanism for generating photocurrent in non-centrosymmetric crystals without semiconductor p–n junction or bias voltage. In this paper, the impact of grain boundaries (GBs) on the performance of photogalvanic device with Janus MoSSe monolayer is theoretically investigated by quantum transport simulations. Two 4|8 GBs along armchair direction are taken into consideration. Under the illumination of linearly polarized light, we observe a significant enhancement of the PGE photocurrent in the visible light region, which can be attributed to the reduction of device's symmetry. The averaged enhancement ratios reach around 20 and 13 for two 4|8 GBs, respectively.