黄铜矿型半导体材料CuAlX2 (X=S,Se, Te)的电子结构和光学性质

采用基于赝势平面波基组的密度泛函理论方法,研究具有黄铜矿结构的CuAlX2(X=S,Se,Te)晶体的电子结构,并预测了它们的线性和非线性光学性质.结果表明:这些化合物具有相似的能带结构,带隙随X原子从S→Se→Te依次减小.三种晶体的静态介电常数、静态折射率和静态倍频系数d36的变化情况与带隙的变化相反,随着X原子自S→Se→Te改变依次递增,但静态双折射率依次递减.该系列化合物的倍频效应主要来源于价带顶附近的占据能带向以Al和X原子的p电子态为主要成分的空带之间的跃迁.在三种晶体中,CuAlTe2除静态双折射率偏小外,其它光学性能要优于CuAlS2和CuAlSe2.

Electronic Structures and Optical Properties of CuAlX2 (X=S, Se, Te) Semiconductors with a Chalcopyrite Structure

Density functional theory(DFT) based on the pseudo-potential plane wave basis set was used to investigate the electronic structures and optical properties of CuAlX2(X=S,Se,Te) crystals with a chalcopyrite structure.The results indicate that these compounds have a similar band structure and the bandgap decreases from S to Te.Except for the static birefringence,which is just opposite to a change in the bandgap,the static dielectric constant,refractive index and second harmonic generation(SHG) coefficient d36 ...