In-depth study on structural, optical, photoluminescence and electrical properties of electrodeposited Cu2O thin films for optoelectronics: An effect of solution pH

Abstract

Cu2O thin films were deposited using electrodeposition method at different pH values of the solution (11, 12 and 13). The prepared films were analyzed by XRD, SEM, EDAX, UV-Vis absorption and Photocurrent-voltage measurements. The XRD study revealed that there is a increase of crystallite size as 33, 42 and 52 nm for films deposited at pH of 11, 12 and 13, respectively. SEM images revealed three-face pyramid shaped grains of increased size for the increase of solution pH. Among all grown films, high absorption is found for film grown at solution pH 13. The band gap values are found to be 2.02, 1.98 and 1.92 eV, respectively for different pH values. Photoluminescence spectra displayed sharp emission peak at 618 nm which confirms the formation of Cu2O structure. The Photo response studies revealed increase of photocurrent with increase of pH value. The observed low resistivity of the films grown at solution pH 13 confirms that the film is of better quality among the other films.