Enhancing Photon Trapping for Optoelectronic Applications Through Controlled Surface Morphology of Electrochemically Deposited CuO Thin Films Using Cyclic Voltammetry

This study demonstrates the significant enhancement of CuO thin film surface morphology through controlled cyclic voltammetry (CV) for optoelectronic applications. Three trials with different numbers of CV sweeps (10, 20, and 30) were conducted. X-ray diffraction (XRD) analysis confirmed a monoclinic structure. It revealed a decrease in crystallite size from 29.6 nm to 23.9 nm as the number of CV sweeps increased, accompanied by an increase in XRD intensity. Scanning Electron Microscopy (SEM) showed groups of spheres with nanosized vacancies as the number of CV sweeps increased. UV-Vis spectrophotometry demonstrated a 20% increase in transmission and a decrease in bandgap energy from 2.5 eV to 2.2 eV. Photoluminescence (PL) analysis indicated a reduction in PL emission intensity with increasing CV sweeps, highlighting the effectiveness of morphology control for targeted photon trapping. The Cu doublet state 2p 1/2 and 2p 3/2 and the oxygen at 1s state could be confirmed using XPS analysis. Also, the surface study of the CuO thin film strengthened the interpretation of the low emission in the thickest films. It reinforced the idea behind the study of surface morphology. These findings provide valuable insights for optimizing CuO thin film surface morphology in optoelectronic devices.