Annealing temperature assisted microstructural and optoelectrical properties of CdSe thin film grown by RF magnetron sputtering

Cadmium selenide (CdSe) thin films are widely used in electronic devices as well as a potential window material in solar cell applications. In this study, 100 nm CdSe thin films were grown on borosilicate glass substrates by using Radio Frequency (RF) magnetron sputtering technique at room temperature (25 degrees C). Deposited films were annealed in a vacuum furnace at 100 degrees C, 200 degrees C, 300 degrees C, 400 degrees C and 500 degrees C for 10 min, respectively. In-depth analysis of the microstructural and optoelectrical properties of annealed films were performed using X-ray diffraction (XRD), UV-Vis spectrometry and Hall Effect measurements. From XRD results, the films illustrated hexagonal structure with preferred orientation (002) at 2 theta = 24.12 degrees. UV-Vis study indicated that the transmission ranges were from 75% to over 85% for annealed samples and the calculated optical band gap was in the range 1.65 eV-1.73 eV. Optical properties demonstrated that CdSe had the potential to be incorporated as a window layer in solar cells. Meanwhile, the electrical measurements showed n-type conductivity with the carrier concentration of 10(14) cm(-3) for all the annealed films. The optimized results recommend sputtered CdSe thin films annealed at 400 degrees C as a possible window layer to the Cd-based solar cells.