利用第一性原理模拟计算铜铟硒(CIS)太阳能电池CIS吸收层,及CIS中普遍存在的有序缺陷化合物（ordered defect compound，ODC）CuIn₅Se₈的性质.依据CuIn₅Se₈形成的方式，结合对称性越高、能量越低的原则，建立CuInS₂中的ODC CuIn₅S₈结构，并从态密度角度讨论CuInS₂与CuIn₅S₈的差异.分别选用ZnSe和CuI半导体作为CIS和CuInS₂电池的缓冲层，利用第一性原理计算得到价带偏移（valence band offset，VBO）.在ZnSe/CIS界面处，CIS的价带顶（valence band maximum，VBM）比ZnSe高0.52 eV；在CuI/ CuInS₂界面处，CuI的价带顶比CuInS₂低0.37 eV，表明CuI非常适合应用于CuInS₂电池缓冲层.ODC中由于Cu的缺失，其d轨道电子和阴离子p轨道电子的p-d排斥力减小，使ODC材料的价带顶相对于自身本征材料有所下降.

The crystal structure of the ordered defect compound (ODC) CuIn₅S₈ was established and its properties were studied and compared with CuInS₂. Further, ZnSe and CuI were chosen as the buffer layers of CuInSe₂ and CuInS₂ solar cells respectively. The valence band offset （VBO） was calculated based on the first principle calculation. On the ZnSe/CIS interface, the valence band maximum (VBM) of CIS was higher than that of ZnS with a VBO by about 0.52 eV due to a larger p-d repulsion in CIS. On the CuI/CuInS₂ interface, VBM of CuI was lower than that of CuInS₂ with a VBO of about 0.37 eV. The p-d repulsion was much weaker in ODC compared with CuInSe₂ and CuInS₂, resulting in a lower VBM.