The Concentration Effect of Complexing Agent on the Morphology and Optoelectronic Properties of Electrochemically Deposited n-type Cu2O Thin Films

In this work, copper oxide (Cu2O) n-type semiconductors were synthesized on fluorine-doped tin oxide (FTO)-coated conducting glass substrates using copper acetate electrolyte through potentiostatic electrodeposition. The effect of the concentration of acetic acid (CH3COOH) as a complexing agent on the growth mechanism, structural, morphological, and optical properties of Cu2O thin films were studied. The obtained results showed that the concentration of acetic acid affects the structure, grain size, surface topography and optoelectronic properties of Cu2O films significantly. X-ray diffraction (XRD) revealed that all the Cu2O films are pure and crystallize in cubic structure with high crystanillity and preferred (111) orientation. Both Mott-Schottky (MS) and photocurrent (PC) measurements confirm the n-type conduction of the deposited films and the enhancement of their electrical properties with increasing acetic acid concentration. Atomic Force Microscopy (AFM) showed the variation in surface topography and roughness of the Cu2O films. The band gap (E-g) of the Cu2O films decreased slightly with increasing the acetic acid concentration. The Cu2O films deposited with 0.04 of acetic acid exhibited better overall properties and are suitable for Cu2O based homo-junction.