Preparation of nanostructured cuprous oxide (Cu₂O) absorber layer for photovoltaic application

Abstract

In this investigation, a nanostructured Cu2O thin film absorber layer is electrodeposited, exploring the impact of varying negative applied voltages and deposition time. Notably, the Cu2O thin film demonstrated optimal absorbance at −0.95 V, contrasting sharply with a minimum at −0.97 V. The authors' findings underscore that the peak absorbance was achieved at −0.95 V, coinciding with the lowest transmittance observed after 80 min of deposition, aligning with a maximal absorption coefficient of 21 × 103 cm−1. At a deposition time of 5 min, the Cu2O thin film exhibited a noteworthy maximum Urbach energy of 2.00 eV and a minimum steepness parameter of 0.013. In contrast, the lowest Urbach energy was recorded at 0.34 eV, with the highest steepness parameter occurring at an applied voltage of 0.93 V. Furthermore, this study revealed a gradual increase in the refractive index with higher applied voltages, reaching its pinnacle at −1.5 V. These results collectively emphasize the nuanced interplay between applied voltage, deposition time and the optical properties of the nanostructured Cu2O thin film. The observed trends hold significant implications for optimizing the performance of thin film absorber layers, particularly in the context of enhancing absorbance and tailoring optical characteristics for specific applications