Cd_(1-x)Zn_xTe材料电子结构和光学性质的第一性原理研究

First-principle Calculations of Electronic Structure and Optical Properties of Cd_(1-x)Zn_xTe

采用基于第一性原理密度泛函理论的CASTEP程序软件包,运用LDA+U的方法,计算了Cd1-xZnxTe的电子结构和光学性质。计算结果表明:通过LDA+U的修正计算,得到的Cd1-xZnxTe禁带宽度与实验值接近,消除了Cd1-xZnxTe材料在电子结构计算中禁带宽度被低估的问题;赝势U的加入增加了轨道电子数目,电子的能级发生分裂,吸收谱图和折射谱图中的峰强增加,峰数减少。

Electronic structure and optical properties of Cd1-xZnxTe have been analyzed using LDA＋U scheme based on the density functional theory of the first principles method with the Cambridge Serial Total Energy Package （CASTEP） code. By using LDA＋U calculations , the band gaps are in good agreement with the experimental results, and the underestimation problem of Cd1-xZnxTe band structure have been solved. The introduction of the U value can not only increase the population of electrons in orbit but also make the electron energy levels split. The intensity of absorption and refractive spectrum peaks increase with the number of peaks decrease.