CdO及CdxZn1-xO化合物的结构、能量和电子性能分析

采用基于密度泛函理论的第一性原理的平面波超软赝势计算方法, 研究了纤锌矿结构的CdxZn1-xO化合物以及CdO在纤锌矿结构、岩盐结构和闪锌矿结构的基态电子特性和体结构, 分析了CdO的稳定性. 通过对比纤锌矿结构、岩盐结构和闪锌矿结构CdO的内聚能, 发现岩盐结构和纤锌矿结构CdO的稳定性好, 闪锌矿结构相对较差; 通过对CdxZn1-xO化合物在不同Cd组分下的电子结构计算, 得到了较好的禁带宽度拟合结果, 能带弯曲参量B=1.02 eV; 通过形成能与组分关系的分析, 我们认为当Cd的组分x=0.4左右时, CdxZn1-xO化合物最不稳定, 容易出现相分离现象.

Structural,Energetical and Electronic Properties of CdO and CdxZn1-xO Compounds

We have studied the structural, energetical, and electronic properties of CdxZn1 -xO films in wurtzite structure and CdO in rocksalt, zinc blende, and wurtzite structures by the method of total energy plane-wave expansion with first-principles ultrasoft pseudo-potential technology based on the density functional theory (DFT). Stabilities of CdO in different structures were analyzed and it was concluded that rocksalt and wurtzite structures of CdO almost had the same stability, but the zinc blende structure was not so stable. From the simulation of CdxZn1-xO films, we obtained the equilibrium lattice constants, the formation energies, and the band gap energy bowing parameter. The results of formation energies revealed that the CdxZn1-xOfilms were unstable at the composition of about x=0.4. Phase segregation between ZnO and CdO might occur at this point.