Texture and Bandgap Tuning of Phase Pure Cu2O Thin Films Grown By a Simple Potentiostatic Electrodeposition Technique

Highly textured phase pure Cu2O thin films have been grown by a simple electrodeposition technique with varying deposition voltages (-0.3 to -1.0 V). The surface morphology characterized by Scanning Electron Microscopy (SEM) revealed that the deposited thin films coherently carpet the underlying substrate and composed of sharp faceted well-define grains of 0.5 – 1.0 µm sizes. XRD analyses showed that all films are composed of polycrystalline cubic Cu2O phase only and have average crystalline domain size in the range 30 – 73 nm. The preferred crystalline orientation of phase pure Cu2O films were found to be changing from (200) to (111) with increasing cathodic voltages and showed highest (111) and (200) crystalline texture coefficient while grown at -1.0 and -0.8 V respectively. Optical bandgap of the as-grown samples were calculated in the range (1.95 – 2.20) eV using UV-Vis Transmission data. The performance of copper oxide films was tested by estimating LED 'ON/OFF' modulated surface photovoltage into a photoelectrochemical cell at a zero bias.