A function of external doping: Characteristics of inorganic nanostructure based diode

Abstract

The present study has been related to synthesis and characterization of ZnO films growth by chemical spray pyrolysis technique. Variation in the characteristics of ZnO film has been evaluated as a function of Cobalt content. The influence of cobalt content on structural, morphological, optical and electrical features have been observed by XRD, SEM, AFM, UV–vis spectroscopy and I-V measurement, respectively. Structural measurements of the samples indicate that all samples have polycrystalline nature with (002) preferential orientation. SEM and AFM images have indicated that films have smooth and uniform morphology. Changes in the surface morphology of the samples have been explained by taking Cobalt incorporation into consideration. Optical studies reveal that the band gap values of the samples exhibit decreasing tendency with Cobalt content. Performance of ZnO films in Schottky diode application has been conducted by evaporation Au contact on ZnO:Co films. From I-V curves of the devices, it has been observed that all devices exhibit good rectifying properties. Also, some diode parameters such as ideality factor, barrier height have been calculated by considering thermionic emission theory (TE) and have been found in the range of 1.89–1.57 and 0.57–0.62 eV, respectively. Additionally, these results and series resistance values of the diodes have been checked and calculated by using Cheung's function. Results showed that all diode parameters highly depended on cobalt concentration. All results have been discussed in detail depending on cobalt incorporation.