(河北工業(yè)大學(xué) 電磁場與電器可靠性省部共建重點(diǎn)實(shí)驗(yàn)室，天津 300130)
摘 要: AgSnO2是一種較為理想的AgCdO替代材料，但由于其中SnO2近乎絕緣，使得觸頭材料的接觸電阻增大，故改善SnO2的導(dǎo)電性是急需解決的重大難題。采用基于密度泛函理論的第一性原理贗勢法，通過建模的方法，分別建立不同比例(50%、25%、16.67%、12.5%、8.34%)La摻雜的SnO2晶胞模型，并計(jì)算分析其晶格常數(shù)、電荷布居、能帶結(jié)構(gòu)和態(tài)密度等性質(zhì)。結(jié)果表明，La摻雜后觸頭材料中的SnO2仍屬于直接帶隙半導(dǎo)體材料，但其禁帶寬度變小，載流子濃度變大，使得材料的導(dǎo)電性增強(qiáng)。當(dāng)La摻雜比為16.67%時(shí)導(dǎo)電性最佳。
關(guān)鍵字: La摻雜SnO2；第一性原理；電子結(jié)構(gòu)；電學(xué)性質(zhì)
（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
