Research On Interface Electron Transfer Characteristics Of Several Types Of Two-dimensional Semiconductor Composite Structural Materials

In recent years, the two-dimensional semiconductor materials have attracted widespread attention owing to their special properties and broad prospects for applying. It is a newly potential material in optics, electricity and magnetism, etc. Compared with the pure two-dimensional semiconductor materials, the composite material is superior. In order to obtain better and widely used new composite materials, we need to modify the two-dimensional materials. Therefor, it is an important method to explore new composite structures by applying the first-principles calculation. At the same time, the method lays the essential theoretical foundation on study of the two-dimensional semiconductor material.The characteristics of interfacial electron transfer of some composite two-dimensional semiconductor structures were investigated by using the first-principles calculation which is based on density functional theory in this article, and the same time, we selected three hot materials which are graphite, g-C3N4 and black phosphorus and studied three composite structures, including g-C3N4 and metal or non-metallic graphene composite structures and mono-black phosphorus defect and doped with sulfur structure. Through calculating and analyzing of the band, the density of states, the binding energy, the charge density difference,work function, bader charge and absorption spectrum of composite structures, some conclusions were as follow:Firstly, we studied g-C3N4 doped with metal. We found that composite structures enhanced the intensity of the visible and infrared light absorption of g-C3N4.Secondly, Graphene@g-C3N4 composite structure with S substituted N atom were investigated. The research showed that these composite structures opened different band gaps of graphene and different position of S which have different band gap. At the same time,compared with pure g-C3N4, this kind of composite structures enhanced the intensity of the visible and infrared light absorption of g-C3N4.Thirdly, We investigated the mono-black phosphorus defect and doped with sulfur. We found that different defects and doping structures had different affection on band gap,magnetic and absorption spectra.