Thermally stimulated current analysis of Zn sub(1-x)Cd sub(x)O alloy films

We have studied the structural and electrical properties of Zn sub(1-x)Cd sub(x)O alloy films deposited by ultrasonic spray pyrolysis technique. XRD measurement indicated that pure ZnO and CdO samples had single phases with hexagonal wurtzite and cubic structures, respectively. However, Zn sub(1-x)Cd sub(x)O alloy films with x = 0.59 and 0.78 exhibited mixtures of a hexagonal wurtzite ZnO phase and a cubic CdO phase. Analysis of thermally stimulated current spectra of Zn sub(1-x)Cd sub(x)O alloy films revealed the existence of a number of overlapped peaks each characterized by different trap energy levels located in the range of 0.033-0.215 eV below the conduction band. We have used curve fitting method for the evaluation of the trap parameters of the alloy films. The values of attempt-to-escape frequency [nu], capture cross-section S and concentration of the traps N sub(t) have been determined.