纤锌矿和亚稳岩盐矿结构氧化锌的电学光学特性

Comparative study on the electronic and optical properties of wurtzite and metastable rock-salt ZnO by density function pseudopotential method

利用密度泛函赝势法对纤锌矿结构和亚稳岩盐矿结构氧化锌电学和光学特性进行了对比研究,计算表明,亚稳岩盐矿结构氧化锌的电离度下降,对于亚稳岩盐矿结构氧化锌得到的GGA带隙略大于纤锌矿结构氧化锌,两种多形体电学结构的差别导致了光学特性的不同.预测了亚稳岩盐氧化锌具有负的微分电导效应,特别是在施主杂质重掺杂的情况下.强烈的电子-光子的耦合以及宽的光学响应区使它更适合于光学领域的应用,特别是在极短的波段,尽管它具有间接带隙的特性.

The electronic and optical characteristics of wurtzite and metastable rock -salt ZnO were given comparative study based on the density function pseudopotential method. Calculation results show that the ionicity of metastable rock - salt ZnO decrease. The GGA energy band gap of metastable rock - salt ZnO is a little bigger than the one of wurtzite ZnO. The differences of electronic structure between the two polymorphs lead to the different optical characteristics. It is predicted that metastable rock -salt ZnO possesses the negative differential conduction, especially when it is heavily doped. The stronger electron -photon coupling and the wider optical response region in the metastable rock - salt ZnO, which makes it more suitable for optical applications especially in the extremely short- wave region, in spite of an indirect band gap characteristic.