Mousumi Kundu, Mst. Halima Khatun, Sajal Khan, Md. Shahjahan
Abstract: Undoped and Pb-doped CdS (Pb: CdS) thin films were prepared by a spray pyrolysis technique on glass substrates at 3000C substrate temperature for different doping concentrations. The physical properties of the films were studied as a function of increasing lead dopant concentration. Structural, optical and electrical properties of these films have studied for photovoltaic applications. The structural and optical properties of the prepared films were characterized using XRD and UV-VIS spectroscopy. X-ray diffraction (XRD) patterns revealed that the samples have hexagonal crystal structure. The particle size of the crystallites was found to be in the range 20-62 nm for CdS film. The optical properties of the Pb: CdS thin films have been studied at room temperature in wavelength range 400 nm to 1100 nm. The variation of energy band gap for the films with different doping concentrations was studied. The resistivity decreases with increase of the temperature which confirms semiconductor behavior and it depends on the doping concentrations. Hall measurements were done in air ambient at room temperature and the samples are found n-type semiconductor.
Keywords: Spray pyrolysis, Dopant, Band gap, CdS