Structural, Optical and electrical properties of CdS annealed thin films

Recent advances in soft solution processing of inorganic materials offer an exciting opportunity to develop large area manufacturing technologies for solar cells. In the present work, cadmium sulphide (CdS) thin films were... [ view full abstract ]

Recent advances in soft solution processing of inorganic materials offer an exciting opportunity to develop large area manufacturing technologies for solar cells. In the present work, cadmium sulphide (CdS) thin films were prepared by chemical bath deposition technique under optimal conditions, and annealed in nitrogen atmosphere at 100, 150, 200, and 250°C. Structural properties of CdS semiconductor were characterized by X-ray diffraction and the XRD patterns indicated the presence of single-phase of hexagonal CdS. Annealing samples at 200°C exhibit compact and well-defined granular structures, containing 56 and 44 At. % of Cd and S, respectively. According to the optical characterization, films without annealing exhibit a band gap of 2.35 eV and after annealing treatment, the band gap of the films changes from 2.3 to 2.4 eV, when annealing temperature increase from 100 to 250 °C. Based on the obtained results through measurements in a 4 points equipment, CdS resistivity varies from 7E8 (annealed films) to the 2.6E9 Ωm2 (as deposited films), those values shows a good agreement with other experimental studies of CdS thin films