Effect of cadmium incorporation on the properties of zinc oxide thin films

CdxZn1−xO (0 ≤ x ≤ 0.20) thin films are deposited on soda lime glass substrates using spray pyrolysis technique. To check the thermal stability, CdxZn1−xO thin films are subjected to annealing. Both the as-deposited and annealed CdxZn1−xO thin films are characterized using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive X-ray analysis (EDAX) to check the structural, surface morphological and compositional properties, respectively. XRD analysis reveals that the both as-deposited and annealed CdxZn1−xO thin films are (002) oriented with wurtzite structure. SEM studies confirm that as-deposited, as well as annealed CdxZn1−xO thin films are free from pinholes and cracks. Compositional analysis shows the deficiency in Cd content after annealing. Optical properties evaluated from UV–Vis spectroscopy shows red shift in the band gap for CdxZn1−xO thin films. Electrical property measured using two probe method shows a decrease in the resistance after Cd incorporation. The results indicate that cadmium can be successfully incorporated in zinc oxide thin films to achieve structural changes in the properties of films.