Impurity induced formation of Sn2+ ions in SnO2 and the photoluminescence property

The photoluminescence properties of doped SnO2 have been investigated. In Eu3+, Sb3+ and Ca2+ doped SnO2, fine structure emissions in the range from 580 to 725 nm are clearly observed. These fine structure emissions have been ascribed to electronic transitions from the split D, C, B and A bands to the ground state under the famous Jahn-Teller effect and the spin-orbit interaction of the dopant induced Sn2+ ions in the doped SnO2. The formation of Sn2+ ions in the doped systems is ascribed to compensate for the discrepancy of the structure and the electronic charge between the host cation and the impurity.