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基于密度泛函理论第一性原理的平面波超软赝势,采用广义梯度近似及Heyd-Scuseria-Ernzerhof 03(HSE03)方法对能带及态密度进行修正,研究了AlN_(1-x)P_x(x=0,0.25,0.50,0.75,1)合金的晶体结构、电子结构和光学性质。结果表明,随P含量的增加,AlN_(1-x)P_x晶格常数呈线性递增趋势,AlN_(1-x)P_x(x=0,0.25,0.75,1)属于立方晶系,而AlN0.50P0.50属于四方晶系。AlN_(1-x)P_x带隙随P含量的增加呈先减后增趋势,AlN和AlP是间接带隙半导体,而AlN_(1-x)P_x(x=0.25,0.50,0.75)属于直接带隙半导体。P的存在破坏了AlN原本的本征值和简并态,改变了电子能带结构。随P含量的增加,AlN_(1-x)P_x的光学性质曲线向低能区移动,介电函数虚部的次强峰逐渐消失。AlN_(1-x)P_x合金对紫外光具有较强吸收,P的存在拓宽了可见光吸收范围。
Based on the first-principles density functional theory (PLFTP) plane-wave ultra-soft pseudopotential, the generalized gradient approximation and the Heyd-Scuseria-Ernzerhof 03 (HSE03) method were used to correct the band and state density. The effects of AlN_ (1-x) x = 0,0.25,0.50,0.75,1) crystal structure, electronic structure and optical properties of the alloy. The results show that the lattice constant of AlN_ (1-x) P_x increases linearly with the increase of P content. AlN_ (1-x) P_x (x = 0,0.25,0.75,1) belongs to the cubic system, 50P0.50 belongs to the tetragonal system. The bandgap of AlN_ (1-x) P_x decreases first and then increases with the increase of P content. AlN and AlP are indirect bandgap semiconductors, while AlN_ (1-x) P_x (x = 0.25,0.50,0.75) belongs to the direct band Slot Semiconductor. The existence of P destroys the original eigenvalues and degenerate states of AlN and changes the electronic band structure. With the increase of P content, the optical property curve of AlN_ (1-x) P_x moves to the low energy region, and the sub peak of the imaginary part of the dielectric function gradually disappears. AlN_ (1-x) P_x alloy has a strong absorption of UV light, and the presence of P broadens the visible absorption range.