Tunable electronic and photoelectric properties of Janus group-III chalcogenide monolayers and based heterostructures

Janus group-III chalcogenide monolayers and based heterostructures with breaking vertical structural symmetry offer additional prospects in the upcoming high-performance photoelectric devices. We studied the geometrical, electronic, and photoelectric properties of Janus group-III chalcogenide monolayers and heterostructures. The most energy favorable stacking design of ten vertical heterostructures are considered. The results showed that the Janus Se-In-Ga-S and S-In-Ga-Se monolayers exhibit semiconducting characteristics with the band gaps of 1.295 eV and 1.752 eV, respectively. Furthermore, the different stacking configurations and surface termination at interface can realize the transition of band alignment between type I and type II due to the interlayer coupling. Moreover, we systematically investigated the photoelectric properties of Janus group-III chalcogenide heterostructures and predicated an optimized power conversion efficiency of 16.2%. These findings can aid in comprehending the customized characteristics of Janus group-III chalcogenide heterostructures, offering theoretical guidance for creating innovative photoelectric devices.