Fabrication and characterization of size-controlled CdS nanostructures by a modified chemical bath deposition method

CdS nanostructures have been grown on glass substrate by a modified chemical bath deposition method (MCBD) using CdCl2 (0.02 M), KOH (0.5 M), NH4NO3 (1.5 M) and HNCSNH (0.2 M) aqueous solutions at the bath temperature of 80°C and the pH of 10.40. Power adjustable Ar-Ion Laser beam with the powers of 150 mW, 250 mW, and 400 mW was irradiated to the glass substrates during the deposition. Optical properties of CdS nanostructures were performed by the UV-Visible spectrophotometer. Energy band gaps of CdS nanostructures have been determined using Tauc method for laser beam powers of 150, 250, and 400 mW, as 2.456, 2.477, and 2.502 eV, respectively. Structural properties of CdS nanostructures have been performed by x-ray diffraction (XRD). The XRD pattern of the CdS nanostructures has shown that their preferred orientation is in the <;111>; direction and they have a cubic structure. Surface morphology has been studied by atomic force microscopy (AFM). AFM results have shown that surface roughnesses of samples were 6.56, 7.52, and 6.21 nm for laser beam powers of 150, 250, and 400 mW, respectively. AFM results also have shown that grain sizes of CdS nanostructures were 50, 40, and 25 nm, for laser beam powers of 150, 250, and 400 mW, respectively.