Abstract: In terms of density functional theory , the electronic structure and optical properties of the Cu substitution doping and vacancy doping SnO 2 were tested , and also the combination of these two types of doping methods were researched .Considering the magnetism of SnO 2 , the magnetic properties after the SnO2 doped with Cu , S were investigated .Calculation shows that the two ways of doping both make the SnO2 have semimetal property and be a strong role in exchanging the Cu atom with the O atoms surrounding with it which contributes to the density of states mainly near the Fermi level .By contrast , the crystal cell volume after vacancy doped is slightly bigger than the substitution doped one .Meanwhile the light energy loss is lower too .The calculation results show that the mixed each Cu atoms will produce 0. 46 μB magnetic moment , and one S atom will introduce 0.36 μB, and the O atoms around the Cu atom also have a certain contribution to the magnetic moment . Through the analysis , the system of the magnetic source mainly comes from Cu-3d and S-3p, and the strong coupling effect between Cu-3d and O-2p.

Key words: In terms of density functional theory , the electronic structure and optical properties of the Cu substitution doping and vacancy doping SnO 2 were tested , and also the combination of these two types of doping methods were researched .Considering the magnetism of SnO 2 , the magnetic properties after the SnO2 doped with Cu , S were investigated .Calculation shows that the two ways of doping both make the SnO2 have semimetal property and be a strong role in exchanging the Cu atom with the O atoms surrounding with it which contributes to the density of states mainly near the Fermi level .By contrast , the crystal cell volume after vacancy doped is slightly bigger than the substitution doped one .Meanwhile the light energy loss is lower too .The calculation results show that the mixed each Cu atoms will produce 0. 46 μB magnetic moment , and one S atom will introduce 0.36 μB, and the O atoms around the Cu atom also have a certain contribution to the magnetic moment . Through the analysis , the system of the magnetic source mainly comes from Cu-3d and S-3p, and the strong coupling effect between Cu-3d and O-2p.