RESUMO
CdS thin films were prepared by chemical bath deposition (CBD) at 90 'C. The influence of annealing and CdCl2 treatment on CBD-CdS thin film was studied. XRD and SEM were used to study the crystal structure and surface morphology ofthe films. The untreated CBD-CdS films had poor crystallinity; the CdS thin film made with annealing treatment had cubic crystallinity but small grain size. After the CdCl2 treatment, these films recrystallized to the hexagonal phase, resulting in a better crystallinity, and smooth surface morphology. Optical properties were studied by absorption spectrum. The energy gap of the films was found to decrease by annealing, and the CBD-CdS made with CdCl2 treatment had a lower density of planar defects. In conclusion, the CdCl2 treatment can improve the properties of the CdS thin films.