Pulse plated CdS xTe 1−x films and their properties

Abstract

CdS x Te 1− x films were deposited on titanium and conducting glass substrates at room temperature using 0.25 M cadmium sulphate, the concentration of sodium thiosulphate and TeO 2 dissolved in sodium hydroxide was varied in the range of 0.01–0.05 M. The as deposited films exhibited hexagonal structure irrespective of the composition. The FWHM maximum of the x-ray diffraction peaks were found to decrease with increase of duty cycle. The optical energy gap values are in the range of 1.54–2.32 eV for films of different composition, it is observed that the band gap shifts towards CdS side as the concentration of CdS in the films increase. XPS studies indicated the formation of CdSTe solid solution. The grain size increases from 11.54 to 99.40 nm as the value of x increases from 0.2 to 0.8. The surface roughness is found to increase from 0.22 to 2.50 nm as the value of ‘ x’ increases from 0.2 to 0.8. The resistivity is found to vary from 53 to 8 ohm cm as the ‘ x’ value decreases from 1 to 0.