硫钒铜矿化合物电子结构和电致变色特性的第一原理研究

基于密度泛函的第一原理赝势平面波方法，计算晶体结构、电子结构和光学性质，研究硫钒铜矿化合物Cu₃VS₄、Cu₃NbS₄和Cu₃TaS₄的电子输运及电致变色特性，探讨作为透明半导体材料应用于太阳能电池和电致变色器件的可能性.电子结构的计算表明这类化合物是间接带隙半导体，其电子能带的导带底和价带顶分别位于布里渊区的X点和R点.价带顶的电子本征态主要来自于Cu原子的d电子轨道，而导带底电子态主要来源于VB族元素原子的d电子轨道.能带结构、电荷布居分析、电子局域化函数和光吸收及反射谱的计算表明这些硫钒铜矿化合物属于极性共价半导体，具有较高的电荷迁移率和优良的电致变色特性，可应用于高效电致变色器件.

Electronic Structure and Electrochromic Property of Sulvanite Compounds: A First-principles Study

With first-principles pseudo-potential plane-wave method, crystal structures, electronic structures and optical properties of sulvanite compounds:Cu₃VS₄, Cu₃NbS₄ and Cu₃TaS₄ are calculated to investigate their electrical conductivity and electrochromic performance. They are potentially applied in solar cells and electrochromic devices as transparent semiconductors. Electronic structures indicate that the secompounds are indirect band-gap semiconductors, with conduction band minimum and valence band maximum located at X and R points, respectively, in Brillouin zone. Electronic states of conduction band minimum and valence band maximum are dominated by d-orbitals of Cu and Ⅴ-group elements, respectively. From band structure, atomic charge population analysis, electron localization function and optical adsorption/reflectivity spectrum it is suggested that these sulvanite compounds are polar covalent semiconductors with high charge transport mobility and extraordinary electrochromic characteristics. They could be applied to electrochromic devices.