高压下AlN的电子结构和光学性质

Electronic structure and optical properties of AIN under high pressure

基于密度泛函理论体系下的广义梯度近似(GGA)方法,利用第一性原理计算了不同压强下六方纤锌矿AlN的晶体结构、电子结构和光学性质.通过比较压力作用下能带结构的变化行为,得出AlN在16.7 GPa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.结合电子结构分析了高压对AlN光学性质的影响,发现在压力的作用下AlN吸收光谱有蓝移的趋势.

We have calculated the electronic structure and optical properties of Wurtzite structure A1N under different high pressure 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 are calculated. By comparing the changes of the energy band structure, we obtained A1N phase transition pressure for 16.7 GPa, which is a direct band structure transforming to an indirect band structure. Meanwhile, according to the density of states distribution and energy band structure, we ana~ lyzed the optical properties of A1N under high-pressure, the results showed that the absorotion Snootrn moved from from low-energy to high-energy.