高压下AlN的电子结构和光学性质

运用密度泛函理论体系下的平面波赝势(PWP)和广义梯度近似(GGA)方法，利用第一性原理计算了不同压强下六方纤锌矿结构AlN晶体的晶格常数、总能量、电子态密度、能带结构、光反射系数与吸收系数。通过比较能带结构的变化行为，得出 AlN在16.7Gpa附近存在等结构相变，即由直接带隙结构转变为间接带隙结构。同时，结合高压下的态密度分布图和能级移动情况，分析了AlN在高压下的光学性质，吸收谱有向高能端移动(蓝移) 的趋势。

Electronic structure and optical properties of AlN under high pressure

We have calculated the electronic structure and optical properties of Wurtzite structure AlN under different high pressure by means of plane wave pseudo-potential method (PWP) with generalized gradient approximation (GGA) in this paper. The total energy, density of state , energy band structure , and optical absorption and reflection properties under high pressure arecalculated. By comparing the changes of the energy band structure obtained in the 16.7Gpa AlN phase transition exists, that is a direct band structure transforms to an indirect band structure. Meanwhile, We analyzed the optical properties of AlN under high-pressure, according to density of states distribution and energy movement.The absorption spectra mobile (blueshift) from low-energy to high-energy.