论文部分内容阅读
采用密度泛函理论框架下的第一性原理平面波超软赝势方法,研究In掺杂对纤锌矿In_xGa_(1-x)N合金的晶格常数、能带结构、态密度和光学性质的影响。计算结果表明:随着In掺杂浓度的增加,晶格常数逐渐增大,导带向低能方向移动,带隙变窄;与此同时,介电函数向低能方向发生了漂移,发生了红移现象。在2.0 eV附近出现了第一个介电峰,在4.76 eV附近出现了最大的介电峰。在大约5.6 eV和9.2 eV处有两个交叉点,当光子能量低于5.6或者高于9.2 eV,低掺杂浓度(小于50%)的吸收系数小于高掺杂浓度的吸收系数;当光子能量在5.6到9.2 eV之间,低掺杂浓度的吸收系数高于高掺杂浓度的吸收系数。研究结果表明In_xGa_(1-x)N合金可以作为太阳能电池以及透明导电薄膜的材料。
The first-principle plane-wave ultra-soft pseudopotential method in density functional theory (DFT) was used to study the effects of In doping on the lattice constant, band structure, density of states and optical properties of wurtzite In_xGa_ (1-x) N alloys influences. The calculated results show that as the doping concentration of In increases, the lattice constant increases and the conduction band moves to lower energy and the band gap becomes narrower. At the same time, the dielectric function drifts toward the low energy direction and a red shift phenomenon. The first dielectric peak appeared near 2.0 eV and the largest dielectric peak appeared near 4.76 eV. There are two intersections at about 5.6 eV and 9.2 eV. When the photon energy is lower than 5.6 or higher than 9.2 eV, the absorption coefficient of the low doping concentration (less than 50%) is less than the absorption coefficient of the high doping concentration. When the photon energy Between 5.6 and 9.2 eV, the absorption coefficient of the low doping concentration is higher than the absorption coefficient of the high doping concentration. The results show that In_xGa_ (1-x) N alloy can be used as a material for solar cells and transparent conductive films.