六方 CaCuCh(Ch= N、P、As、Sb、Bi)电子结构和光学性质的第一性原理计算

In recent years, p-type transparent conducting non-oxide materials have attracted extensive attention from many researchers. In this paper,based on the first principles of density functional theory, the geometric structure of hexagonal non-oxide CaCuCh (Ch=N, P, As, Sb, Bi) are optimized, and its electronic structure and optical properties are calculated and analyzed. The calculated results show that CaCuP, CaCuAs and CaCuSb belong to indirect bandgap semiconductors with bandgaps of 0.155, 0.247 and 0.065 eV, respectively, while the energy bands of CaCuN and CaCuBi pass through the Fermi surface and exhibit metallic properties. The analysis of state density shows that the conduction band is mainly composed of Ca-4s and Ch-p states, and the valence band near the Fermi plane is mainly composed of Cu-3d states, and Ch-p states are hybrid. Finally, the optical properties of hexagon CaCuCh in the direction of (100) and (001) with the change of photon energy are obtained, including complex dielectric function, complex refractive index, reflection spectrum, absorption spectrum, loss function and photoconductivity spectrum. The results show that hexagonal CaCuCh has optical anisotropy in (100) and (001) directions, which provides a theoretical basis for the application of hexagonal CaCuCh.