Numerical modeling of effect of annealing on nanostructured CuO/TiO₂ pn heterojunction solar cells using SCAPS

The problem of global warming has led to increased research on solar energy and other renewable energy. Solar cells are a building block of solar energy. Different materials for solar cells fabrication exist with silicon-based being commercially viable and common. The bulk of the alternate materials aimed at providing cheap, efficient and sustainable solar cells. Nanostructured Metal oxides solar cells goes a step further to providing a clean, affordable, sustainable solar cells although the efficiency is still low. This study examined the numerical modelling of the annealing effect on the efficiency of nanostructured CuO/TiO₂ pn heterojunction using SCAPS. The motivation for the study is to provide a basis for experimental design of affordable, non-toxic and efficient alternate material for silicon solar cells. The modelling was performed using Solar cells capacitance simulator (SCAPS). The input parameters, obtained from literature, include a working point of 300 K for the as-deposited CuO/TiO₂ which was compared with air and nitrogen annealed (423.15 K) nanostructured CuO/TiO₂ pn heterojunction. Other working condition included simulated sunlight using illumination of AM 1.5G with a 500 W Xenon lamp, silver was used as the electrode/contact. Film thickness of 2000 nm and 200 nm for absorber and buffer respectively. The results gave an optimum efficiency of 0.47 obtained from Nitrogen annealed CuO/TiO₂ pn heterojunction. Also, the optimum Fill Factor was obtained to be 64.01% from Nitrogen annealed. The annealed samples performed better than the as-deposited CuO/TiO₂ pn heterojunction. This result will help in the experimental fabrication of improved efficiency metal oxide-based solar cells.