A study of Tin doping effects on physical properties of CdO thin films prepared by sol–gel spin coating method

•Sn doped CdO thin films prepared by sol–gel spin coating method.•SEM images show uniform surface morphology.•The contact angle measurement indicates reduction of the surface roughness.•The band gap is widened with increasing Sn doping concentrations.

Transparent conducting Tin doped Cadmium oxide thin films were prepared by sol–gel spin coating method with different Sn concentrations. X-ray diffraction analysis reveals the polycrystalline nature of the Cadmium oxide (CdO) with cubic structure and show preferential orientation along (111) plane. The surface morphology of prepared films was analyzed by SEM and surface roughness variations analyzed by water contact angle measurement. The EDX spectra confirmed the presence of Cd, Sn and O elements in the films. The blue shift of energy gap from 2.42 to 2.96 eV is explained by Burstein–Moss effect. The presents of functional groups and the chemical bonding are confirmed by FTIR spectra. The minimum electrical resistivity (1.12 × 10−4 Ω cm) and maximum carrier concentration (9.94 × 1021 cm−3) was obtained for 5% of Sn doped CdO thin film.