First Principles Simulation Of Two-dimensional Semiconductor Material

2D materials have become the most popular research field due to ultrashort characterize channel length which is decided by their ultrathin thickness. Researchers studied 2D graphene-like inorganic materials as well as the hottest material graphene. In this paper, we simulated the application of germanene and phosphorene in microelectronic and optoelectronic field.Firstly, we investigated electronic properties of halogenated germanene. The delocalized π bond characterize was broken by halogen element via combination of covalent bonds. Thus, germanene open an adjustable bandgap. F, Cl, and Br can open an obvious bandgap, but I element only broke Dirac cones due to small interaction. Moreover, the electronic properties of halogenated germanene can be further modulated by strain and stacking. Bandgap of halogenated germanenes can be continuously modulated by compressive and tensile strains. Even, GeI can open a bandgap. Bandgaps of halogenated germanene present parabola with the increasing strain from -10% to 10%. And the maximum values were located between -8% to-5%. The bandgaps were influenced by strain and layer stacked while bilayer structure was stacked by monolayer. And the bandgap was increased through the competition of strain and stacking. Interestingly, GeX has no direct-indirect bandgap transition in this research. Hence, GeX may have great potential in microelectronic and optoelectronic field.Then, we investigated the properties of a antimonide-phosphorene. The bandgap of phosphorene was reasonable for microelectronic devices and the mobility was not unusable. However, the mobility was lower than modern silicon materials. The band structure went through direct-indirect-direct transition. And the monolayer Sb1-xPx can satisfy the requirement of direct bandgap, reasonable bandgap, and superior mobilities. Thus, Sb1-xPx can be a new 2D channel material in post-silicon era.