Photovoltaic Properties of Aluminum Doped Zinc Oxide Electrodes Based on Variation of Aluminum Impurities in the Semiconductor

Abstract

Photoelectrochemical (PEC) solar cell studies of Al doped zinc oxide (AZO) thin film electrodes has been carried out by photocurrent-voltage (I-V) characteristic. The concentration of Al in ZnO was varied between 1-5 at.% in order to study the effect of the variation on the photovoltaic performance of the electrodes. The current-voltage (I-V) characteristics measured in the dark and under 80 W simulated illumination revealed enhanced PV performance for the AZO electrodes in contrast to the undoped electrode. The best response was achieved for AZO electrode with 2 at.% Al concentration thus, recording higher conversion efficiency and fill factor. This is a clear indication that AZO electrodes are superior to undoped ZnO in PV applications. The remarkable enhanced properties of Al doping on ZnO were carefully studied by means of thickness measurement, X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-Vis spectroscopy, and the results were in good agreement, and confirmed that AZO thin film electrodes are better for PV applications than undoped ZnO semiconductor in sodium sulphate (Na2SO4) electrolyte.