Abstract: In order to improve the electrical properties of the AgSnO2 contact materials,the La,Ce,Y and In co-doped methods of rare earth materials are proposed because SnO2 is close to insulation.Based on the first-principles of density functional theory,SnO2,rare earth elements doped and rare earth elements,In co-doping with SnO2 are used to calculated band structure and density of states,the results show that the doped material is still a direct band gap semiconductor material and thermal stability,the co-doped can further move the conduction band bottom and valence band top near the Fermi level to narrow the band gap,Co-doped than the single-doped electrons with low mass and high conductivity,the conductivity of Y and In co-doped with SnO2 is the best.The co-doping is better than rare earth elements doped about electrical conductivity,which provides the theoretical basis for the development of contact materials.

Key words: In order to improve the electrical properties of the AgSnO2 contact materials,the La,Ce,Y and In co-doped methods of rare earth materials are proposed because SnO2 is close to insulation.Based on the first-principles of density functional theory,SnO2,rare earth elements doped and rare earth elements,In co-doping with SnO2 are used to calculated band structure and density of states,the results show that the doped material is still a direct band gap semiconductor material and thermal stability,the co-doped can further move the conduction band bottom and valence band top near the Fermi level to narrow the band gap,Co-doped than the single-doped electrons with low mass and high conductivity,the conductivity of Y and In co-doped with SnO2 is the best.The co-doping is better than rare earth elements doped about electrical conductivity,which provides the theoretical basis for the development of contact materials.