Effect of films morphology on the performance of Cu₂O PEC solar cells

Copper oxide, a p-type semiconductor, offers multiple device applications due to the lower band gap, non-toxic nature and perfect band alignment necessary for solar water splitting. We report the synthesis of copper oxide thin films on ITO glass substrates via electrodeposition technique. The results of this study manifest variation in particle size, crystallite orientation, shape and crystallinity of the films as a function of current density. We further conclude that significant variations in the efficiency of Photoelectrochemical (PEC) solar cell are attributed to the particle size and crystals faces exposed at the junction interface. The optimized parameters relevant to the efficient PEC solar cell are experimental identified as; open circuit voltage (V_OC) = 0.370 V, short circuit current density(I_SC) = 1.48 mA/cm², fill factor (FF) = 0.50 and η = 0.28%, with high shunt resistance and lower series resistance corresponding to a current density of −1.0 mA/cm². Mott–Schottky plots illustrate that the flat-band potential and charge carrier concentration increase with the particle size, crystallinity, and orientation of crystal faces.