纳米AgSnO2/Bi2O3触头材料的性能及导电机理研究

添加少量第三种元素的AgSnO2触头材料的电性能研究均处在试验阶段而未深入到理论研究阶段.本文采用溶胶-凝胶法制备纳米级AgSnO2/Bi2 O3触头材料,材料的密度为9.73 g/cm3、硬度为105.35HV、电导率为70.22;IACS,并且接触电阻较小.在掺杂Bi元素提高触头材料性能的基础上,进行导电机理的研究.从微观原子角度采用第一性原理的计算方法,计算了Bi掺杂SnO2的电子结构、能带图、态密度及电荷密度分布.结果表明,Bi掺杂后带隙减小,电子跃迁容易,同时费米面附近载流子浓度增大,增强了材料的导电性.最终得出添加少量Bi元素能够使得AgSnO2触头材料的导电性增强的机理.

Study on Properties and Conductive Mechanism of Nano AgSnO2/Bi2O3 Contact Materials

The electrical properties of AgSnO2 contact material with a small amount of the third element are in the experimental stage , but no theoretical reports were reported .Nano AgSnO2/Bi2O3 contact materials were prepared by sol-gel method.The density of the contact material is 9.73 g/cm3 , hardness is 105.35HV, conductivity is 70.22;IACS, and the contact resistance is smaller .On the basis of doping Bi can improve the properties of contact materials , the conductive mechanism was studied .The results show that the band gap becomes smaller , the electronic transitions easily , and the carrier concentration near Fermi level increases after Bi doping , which made the conductivity of the material enhanced.Finally, the mechanism of enhancing the electrical conductivity of AgSnO2 contact materials by adding a small amount of Bi elements was obtained .