Transparent conducting ZnO-CdO mixed oxide thin films grown by the sol-gel method.
Mixed oxides of zinc and cadmium with different proportions were deposited on ordinary glass substrates using the sol-gel spin coating method under optimized deposition conditions using zinc acetate dihydrate and cadmium acetate dihydrate as precursors. X-ray diffraction patterns confirmed the polycrystalline nature of the films. A combination of cubic CdO and hexagonal wurtzite ZnO phases was observed. The oxidation states of Zn, Cd and O in the deposited films were determined by X-ray photoelectron spectroscopic studies. Surface morphology was studied by scanning electron microscopy and atomic force microscopy. The compositional analysis of the thin films was studied by secondary ion mass spectroscopy. The transmittance of the thin films was measured in the range 300-800nm and the optical bandgap was calculated using Tauc's plot method. The bandgap decreased from 3.15eV to 2.15eV with increasing CdO content. The light emission properties of the ZnO:CdO thin films were studied by photoluminescence spectra recorded at room temperature. The current-voltage characteristics were also assessed and showed ohmic behaviour. The resistance decreased with increasing CdO content.
Department of Physics, University of the Free State, Bloemfontein, South Africa; Semiconductor Physics Laboratory, Department of Physics, Gurukula Kangri University, Haridwar, India. Electronic address: tpathak01@gmail.com.
Trilok K
TK
Pathak
Semiconductor Physics Laboratory, Department of Physics, Gurukula Kangri University, Haridwar, India.
Jeevitesh K
JK
Rajput
Department of Physics, University of the Free State, Bloemfontein, South Africa; Photovoltaic Laboratory, Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi, India.
Vinod
V
Kumar
Semiconductor Physics Laboratory, Department of Physics, Gurukula Kangri University, Haridwar, India.
L P
LP
Purohit
Department of Physics, University of the Free State, Bloemfontein, South Africa.
H C
HC
Swart
Department of Physics, University of the Free State, Bloemfontein, South Africa. Electronic address: KroonRE@ufs.ac.za.
R E
RE
Kroon
Electrical properties; Optical properties; Sol-gel; Thin film; X-ray diffraction