Efect of Ag incorporation on structural and opto‑electric properties of pyrolized CdO thin flms

We have investigated the structure, morphology and opto-electric properties of CdO and Ag-incorporated CdO thin flms prepared by chemical spray pyrolysis (CSP) method. The X-ray difraction (GIXRD) study confrms that CdO samples are highly polycrystalline with cubic structure. The AFM study shows smooth surfaces both for CdO and Ag-CdO thin flms. The direct band gap energy varies from 2.25 to 2.50 eV depending on Ag content in the flms. Urbach energy reversal in optical band gap indicates that several localized states are present above Fermi level or near at the conduction band. The optical properties, such as refractive index, optical conductivity and nonlinear optical susceptibility, are found dependent on Ag content. A combined efect on the transport properties has been observed with the incorporation of Ag in CdO. The metal-like electric conduction of CdO flm has been removed up to a temperature Tc for Ag doping. The n-type carrier concentration of CdO is reduced with increasing Ag content and the concentration is of the order of~1020 cm−3.