摘要
近年来,p型透明导电非氧化物材料受到了诸多研究者的广泛关注.基于密度泛函理论的第一性原理方法,优化了六方非氧化物CaCuCh(Ch=N、P、As、Sb、Bi)的几何结构,并计算分析了其电子结构和光学性质.计算结果表明,CaCuP、CaCuAs和CaCuSb属于间接带隙半导体,其带隙分别为0.155、0.247和0.065 eV,而Ca-CuN和CaCuBi的能带穿过费米面,呈现金属性.态密度分析表明,导带主要由Ca-4s和Ch-p态构成,费米面附近的价带主要由Cu-3d态构成,同时杂化了 Ch-p态.最后,得到了六方CaCuCh在(100)和(001)方向上的光学性质随光子能量的变化关系,包括复介电函数、复折射率、反射光谱、吸收光谱、损失函数和光电导谱.结果表明,六方CaCuCh在(100)和(001)方向上具有光学各向异性,这为六方CaCuCh的应用提供了理论依据.
Abstract
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 Ca-CuSb 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 Ca-CuCh.
维普
万方数据