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

Abstract

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.

Keywords

• Sn doped CdO thin films
• Sol–gel method
• X-ray diffraction
• Contact angle
• Electrical properties