Effects of Samarium Doping on Optical Properties of Zn0.9 (Co1-xSmx)0.1O Diluted Magnetic Semiconductor

Transparent ZnO and Zn0.9(Co1-xSmx)0.1O (x = 0.0, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.0) films were prepared by sol-gel method. For the prepared Zn0.9(Co1-xSmx)0.1O systems, the influences of dopant concentration of Sm on the structural and optical properties were investigated. Three additional absorption peaks around 570, 620, and 660 nm wavelengths were observed in low Sm content films, which is attributed to the d-d transitions of Co2+ ions in tetrahedral crystalline. The redshift of band gap in doped samples was discussed in detail.