Comparative Analysis of the Photovoltaic Properties of Copper (I) Oxide/Copper (I) Sulphide [N-Cu2O/P-Cu2S] Heterojunction Solar Cells Fabricated by Immersion and Heating Techniques

Cuprous oxide (Cu2O) is a promising semiconductor material for photovoltaic devices due to its low cost, non-toxicity, and high absorption coefficient. This study successfully deposited n-type Cu2O layers using two electroless methods: immersion and heating. The heating method involved annealing the sample in a copper sulfate solution at 800 for one hour. As the second layer, the p-type copper (I) sulphide was formed on an n-Cu2O substrate by sulfidation using 0.05M Na2S to form the desired n-Cu2O/p-Cu2S heterojunction solar cell. The morphological and structural analyses of the materials were carried out using a Scanning Electron Microscope (SEM) and X-ray diffractometer (XRD), respectively. The SEM shows that the n-Cu2O layer is composed of grains of different sizes, which were improved by annealing the sample at 300oC. The results showed that the immersion method produced a solar cell with improved photoresponse, yielding an open-circuit voltage (Voc) of 77 mV and a short-circuit (Isc) of 16 µA, compared to the heating method, which gives a response of: Voc = 40 mV and Isc = 8 µA.