“…Currently, various types of Janus 2D materials have been theoretically predicted, including Janus transition-metal dichalcogenides, , Janus M 2 XY (M = Ga and In; X/Y = S, Se, and Te), Janus MoSO, , and so on. Especially gallium or indium-based Janus monosulfide compounds have been explored theoretically and experimentally. − Liu et al proposed a class of Janus III group monosulfide compounds of monolayer M 2 OS (M = Ga, In) structure . They pose a low risk of environmental implications. , It is reported that the electron mobility of monolayer In 2 OS exceeds 3 × 10 3 cm 2 V –1 s –1 , , and monolayer Ga 2 OS has a direct band gap structure .…”