Potentiostat Electro-Deposited Cuprous Oxide and Cupric Oxide Thin Films for Photovoltaic Use

Abstract

To withstand the rising demand for energy while fuel and chemical energy are becoming rare, the development in the production of solar energy has become a necessity. There is a variety of solar cells; among them, thin-film photovoltaics is more popular because of low-cost production and good-efficiency. Nowadays, copper oxide has become popular to make thin film layers like CZTS, CIGS, etc. Unfortunately, the efficiency of these thin films is less than 20%. In order to obtain better efficacy, an investigation of the layers of thin films is needed. This research discussed the properties of copper and its oxides. In case of making the thin film layers, potentiostat electro-deposition was the chosen method where bath composition of CuSO₄.5H₂O solution, temperature, time, potential difference were the variable parameters. The best-deposited layers were obtained in 0.2 M concentration, 40 minutes, -0.5 V potential difference and 65^oC. Hence, physical properties like thickness and hardness, and characterisation properties like X-ray diffractometry (XRD), scanning electron microscopy (SEM), UV-Vis spectrometry are observed to compare cupric oxide (CuO) and cuprous oxide (Cu₂O) thin films. CuO thin film shows better stability and rigidity than the Cu₂O thin film. But the thin film layer of cuprous oxide illustrates good homogeneity and nodular form. From the test mentioned above data, band gap has been measured for each deposited film, and the CuO thin film layer is raked out having a better band energy gap than the Cu₂O thin film layer.