Comparison of optical properties of CdS thin films synthesized by spray pyrolysis and thermal evaporation method

Cadmium sulfide (CdS) thin films were deposited on glass and silicon (100) substrates by thermal evaporation method. The structure and microstructure of the CdS thin films were investigated by X-ray diffraction and scanning electron microscopy and Raman spectra. The optical properties were studied using transmittance spectra. The optical band gap energy was estimated at different annealing temperatures by Tauc's method. The refractive index of the films was estimated by the envelope method. The optical band gap energy was found to be 2.427 eV for films deposited on glass at room temperature. CdS thin films were also prepared by the spray pyrolysis method and the optical properties of the films were compared.