高压下闪锌矿InN光电性质的密度泛函研究

 采用密度泛函理论，计算了闪锌矿型InN在压力下的结构、力学性质和光学性质，结果显示，随着压强的增大晶格常数减小。给出了零压下C₁₁、C₁₂、B、C_s、C₄₄的值及至70 GPa压力下弹性常数随压强的变化关系。结果表明，C₁₁、C₁₂、B随压强增大而增大，C_s、C₄₄随压强增大而减小，计算结果与现有实验和理论结果符合较好。在价带区，InN的分态密度（PDOS）有两个带，且在费米面附近密度很小，显示其倾向于形成稳定结构并且导电性较差。对闪锌矿型InN在高压下的光学性质研究发现，导带电子向高能方向偏移，而价带电子向低能方向偏移，结果导致能带间隙增大，光吸收谱在压力的作用发生了“蓝移”。研究结果对认识高压下闪锌矿型InN的结构、电学及光学性质具有重要意义。

Density Functional Theory Studies of the Electronic and Optical Properties of Zinc Blende InN under High Pressure

First-principles density functional studies of the properties of zinc blende InN are presented. We have employed density functional theory, as implemented in the CASTEP code, to investigate the electronic, elastic and optical properties of the material zinc blende InN under hydrostatic pressure range up to 70 GPa. The optimized geometrical lattice constant of InN in the ground state obtained by using generalized gradient approximation is in good agreement with existing results and the lattice constants with pressure increasing. The calculated partial densities of states (PDOS) of the material have two regions in the valence band of InN. It is shown that the PDOS is quite low in the vicinity of the Fermi level, implying that  it tends to form stable structure but has a poor conductivity. The elastic tensor components have linear scaling with pressure, C₁₁, C₁₂ and  B have a positive scaling with pressure. Whereas C₄₄ and C_s have a negative scaling. The absorption spectra move towards the shorter wavelength direction. The shape of the spectra has almost no change when pressure increases. The results presented in this work are helpful for re-evaluating much of the pressure dependence of the properties for the material InN.