LAUSR

Abstract The effect of Sn codoping on the local Co structural environments of the (In 0.95-x Sn x Co 0.05 ) 2 O 3 (x = 0, 0.02, 0.05, 0.08) films has been investigated in detail by x-ray absorption spectroscopy at Co K-edge and L-edge. The results show that the Sn codoping can remarkably influence the local Co structures of the films. For the films with low Sn concentration (x ≤ 0.02), most Co 2+ atoms substitute for In 3+ sites of In 2 O 3 lattices, while a part of Co atoms form the precipitate of Co metal clusters. With further increasing Sn concentration (x > 0.02), the doped Co atoms are completely substitutionally incorporated into the In 2 O 3 lattices. It can be concluded that the codoping of Co and Sn atoms forms p-n pairs of electronics and holes with opposite charge state, which can activate the substitution of Co atoms in In 2 O 3 lattice and suppress the forming of metallic Co clusters. The p-n codoping method can provide a powerful guiding principle in designing the oxides based diluted magnetic semiconductors.