The investigation of the annealing temperature for CdS cauliflower-like thin films grown by using CBD

The Cadmium Sulfide (CdS) cauliflower-like thin films were prepared on glass substrates by using chemical bath deposition at 80 A degrees C. The films were annealed at different temperatures (373, 473, 573, 673 and 773 K) for 1 h at ambient air. The XRD results showed that these films were both in cubic and hexagonal structure and there was no structural alteration among films at different annealing temperatures. The SEM images depicted that the as-deposited film and the film annealed at 373 K had a conifer-like structure; at higher annealing temperatures, the conifer-like structures combined and formed cauliflower-like structures. Also, it was found that the optical band gap decreased from 2.42 to 2.39 eV, with the increase of annealing temperature. The electrical measurements (resistivity, carrier concentration and mobility) of the CdS films were carried out by means of Hall Effect at room temperatures.