(河北工业大学 电磁场与电器可靠性省部共建重点实验室，天津 300130)
摘 要: AgSnO2是一种较为理想的AgCdO替代材料，但由于其中SnO2近乎绝缘，使得触头材料的接触电阻增大，故改善SnO2的导电性是急需解决的重大难题。采用基于密度泛函理论的第一性原理赝势法，通过建模的方法，分别建立不同比例(50%、25%、16.67%、12.5%、8.34%)La掺杂的SnO2晶胞模型，并计算分析其晶格常数、电荷布居、能带结构和态密度等性质。结果表明，La掺杂后触头材料中的SnO2仍属于直接带隙半导体材料，但其禁带宽度变小，载流子浓度变大，使得材料的导电性增强。当La掺杂比为16.67%时导电性最佳。
关键字: La掺杂SnO2；第一性原理；电子结构；电学性质
（Province-Ministry Joint Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability Hebei University of Technology, Tianjin 300130, China）
Abstract:AgSnO2 is an ideal substitute material for AgCdO electrical contact material. However, due to the near insulation of SnO2, the contact resistance of this material increases, so improving the electrical conductivity of SnO2 is an important problem to be solved. By using the first-principle method based on the density functional theory, different proportions (50%, 25%, 16.67%, 12.5%, 8.34%) of La doped SnO2 were established respectively, then lattice constant, Mulliken population, band structure and density of states were calculated. The results show that La doped SnO2 is also direct band gap semiconductor material, the band gap becomes smaller, the carrier concentration becomes larger, and the conductivity is enhanced. The doping ratio is 16.67% when the conductivity is the best.
Key words: La-doped SnO2; first-principle; electronic structure; electrical property
