CHALCOGENIDE LETTERS, cilt.9, sa.1, ss.27-40, 2012 (SCI-Expanded)
CdS thin films with different pH values changing from 9 to 12 were deposited on glass substrates using chemical bath deposition technique (CBD). The effect of pH on the structural, optical and electrical properties of CdS thin films is investigated. X-ray diffraction, Ultraviolet-visible absorption spectroscopy, Scanning electron microscopy, Energy dispersive X-ray analysis, and Raman spectroscopy were used to characterize the thin films. X-ray diffraction data reveal growth of the cubic phase with preferential orientation along (1 1 1) direction. Raman peaks appearing at 296 cm(-1) and 593 cm(-1) for all samples were attributed to 1LO and 2LO phonons of CdS, and they shifted to the blue region with increase in pH values. The band gap of the films increased from 2.29 to 2.40 eV with increasing pH values. Resistivity, carrier density and mobility of the films were determined using Hall effect measurements. After all investigations, it was concluded that the pH value of 11 is suitable for producing CdS thin films by chemical bath deposition technique. The formed film was transparent, uniform and with good adherence to the substrate. These results indicate that films obtained at pH 11 by CBD are good candidates for applications in different optoelectronic devices.