为了研究外压调制对半导体材料 ZnO 晶体结构和光学性质的影响, 采用基于密度泛函理论 (DFT) 的第一性原理 对不同外压条件下 ZnO 晶体的晶格常数、介电函数、复折射率、吸收系数、反射率等的变化特性进行了模拟计算研究。 计算结果表明:随着压力的增大, 晶体的晶格常数、晶胞体积缓慢变小, 内坐标u值逐渐增大, Zn-O 键长缩短, 共价性增强, 带隙Eg明显展宽。光学特性谱显示不同外压对低能段光学性质的影响并不明显, 而在高能段, 随着压力的增大光学性质发生明显的蓝移。

The effect of pressures to ZnO structures and optical properties was studied. All the work was performed by adopting the first-principles based on the density function theory(DFT). The electronic structures were optimized under different pressures. The dielectric function, complex refractive index, absorption coefficient and reflectivity for ZnO were calculated and analysed at 0, 2, 4, …, 12 GPa. The results indicate that, with pressure increasing, the lattice constants and cell volume become smaller, the internal parameter u increases, bond of Zn-O becomes shorter, the covalency is enhanced and the band gap becomes wider. The spectral graphs show that pressures have little effect on optical properties in low energy region, but all the optical properties have obvious blue shift with the increase of pressures in high energy region.