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

Abstract

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.