Abstract: 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 .

Key words: 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 .