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In this paper, the effects of F, S, Se and Te doping on the interfacial interaction and electronic structure of ZnO/graphene heterojunctions were systematically studied based on first-principles. The results show that the ZnO/graphene heterojunction layers are bonded by van der Waals force to form a stable heterojunction and an n-type Schottky barrier. The differential charge density diagram shows that the electrons of the graphene layer transfer to the ZnO layer, making the surface of the graphene layer positively charged and the surface of the ZnO layer negatively charged, forming a built-in electric field at the interface. When F atoms are added, the heterojunction presents ohmic contact. When S, Se and Te atoms are added, the contact types of the heterojunction Schottky change from n type to p type, and the height of the Schottky barrier effectively reduces, especially after Te atom is added, the height of the p type Schottky barrier reduces to 0. 48 eV, which improves the electron injection efficiency. The research results of this paper will provide reference for the design and manufacture of related. [ABSTRACT FROM AUTHOR]

Based on the first-principles calculations of density functional theory, the stability, electronic structure, and optical properties of single layer GeC, N-doped, As doped, and N-As doped GeC systems were systematically studied. The results show that the single layer GeC is a direct bandgap semiconductor with the bandgap of 2. 10 eV. Compared with the single layer GeC, the bandgap and work function of the doped system decrease, indicating that the required energy for electronic transition is relatively small in our doped system. Moreover, the light absorption coefficient of the doped system improves, and the absorption band edge has also undergone a red shift, effectively expanding the response range of the system to light and improving the absorption ability of the system to photons. In addition, the As doped GeC system not only exhibits impurity levels near the Fermi level, but also shows the optimal optical properties such as absorption coefficient, static dielectric function, and extinction coefficient in the low energy region. The above research can provide a theoretical basis for the preparation of relevant GeC photoelectric experiments. [ABSTRACT FROM AUTHOR]