“…Recently, due to the large band gap, good carrier mobility, high stability, and ease of manufacturing, 12 group III–VI monolayers with the chemical formula of MX (M = In, Ga; X = Se, S, Te) have attracted great interest in nanodevices, 13,14 spintronics, 15,16 thermoelectricity, 17,18 optoelectronics, 19,20 photodetectors, 21,22 as well as catalysts. 23,24 Recently, the GaSe monolayer has been experimentally fabricated from the exfoliation of its bulk phase, 25,26 which exhibits excellent infrared-to-ultraviolet tunable optical activity and tunable electronic character.…”