Performance analysis of Schottky diodes based on Bi doped p-ZnO thin films

In the present paper, Bismuth (Bi) doped ZnO thin film have been deposited using sol gel spin coating technique to produce p-type ZnO films on n-Si substrate. The deposited Bi doped ZnO thin films were characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), hot point probe and hall measurement. The XRD and AFM characterization results shows uniform growth of the film over the entire substrate having polycrystalline nature of the film and Hall measurement and hot point probe method shows p-type nature of the deposited Bi doped ZnO film. Further, Palladium (Pd) and Nickel (Ni) metal contacts have been deposited over separate Bi doped ZnO thin films using vacuum coating method to fabricate Schottky diodes. The current voltage characteristics have been analyzed by using conventional thermionic emission model, Cheung's method and Norde's technique to calculate the barrier height, ideality factor and series resistance of the fabricated Schottky diodes. From the calculations, it is observed that Cheung's method gives more realistic results for estimating diode parameters.