The electronic structure of GeSe monolayer with light nonmetallic elements decoration

As a member of the binary group-Ⅳ monochalcogenide monolayer materials, GeSe monolayer possesses better property than most others due to its direct band-gap and small carrier effective mass. Hence, we chose GeSe monolayer as the object to embellish and modify. Using density functional theory calculations, we have investigated its tunable electronic and magnetic properties via absorbing light non-metallic atom (H, F, Cl). From our study, we can see that, in H adatom-decorated system, the electronic property of GeSe monolayer can be effectively manipulated, and keeps the direct band-gap in most situations. H adatom-decorated structures have dilute magnetic states. Most of them cause a bipolar semiconducting behavior, while the rest owns a spin-gapless-semiconducting feature. For most of the F and Cl adatom-decorated systems, they own p-type semiconducting feature. Meanwhile, the magnetism appears only in F adatom-decorated D-Se structure. These results demonstrate that the decoration for GeSe is an available approach to tune its electronic and magnetic properties. After the modification, the GeSe monolayer shows desirable potential in the application of spintronics and optoelectronic devices.