The effect of deposition cycles on structural, morphological, optical and gas detection properties of Mg doped ZnO thin films

Abstract

In this study, Mg doped ZnO thin films were successfully prepared using the modified SILAR approach throughout various numbers of deposition cycles. XRD data shows the prepared films have a ZnO wurtzite hexagonal structure. The crystalline size and crystallinity were found to be increased by increasing the number of deposition cycles. FESEM showed there are nanoparticles and nanorods on the surface, with random distribution in the case of the sample synthesized with 30 cycles, while the agglomeration of nanoparticles to form a maize-like structure and flower-like morphology was predominant in the case of the sample with 40 cycles. The UV-VIS transmittance spectra showed a decrease in transmittance by increasing the number of deposition cycles, and the increment of energy band gap by increasing the number of deposition cycles was found. The response of the samples towards NO2 gas at 200 °C operating temperature was found to be enhanced in the case of the sample prepared at 40 cycles as compared to the sample prepared at 30 cycles.