"Enhancing structural and optical properties of CuO thin films through gallium doping: A pathway to enhanced photoluminescence and predict for solar cells applications"

Abstract

This study explores the transformative impact of gallium (Ga) doping on the structural and optical properties of copper oxide (CuO) thin films synthesized via chemical bath deposition (CBD) to Enhanced Photoluminescence. Structural analysis using X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that moderate Ga doping significantly enhanced crystallinity, improved grain connectivity, and minimized defects. However, excessive doping levels led to phase segregation and structural inconsistencies. The crystalline size (D) was meticulously analyzed using Williamson-Hall (W-H) and Scherrer methods based on XRD data. Optical characterization through UV–Vis spectroscopy demonstrated a remarkable redshift in the absorption edge, attributed to Ga-induced bandgap modifications at the optimal doping concentration of 0.4 M decreased from 2.60 eV to 1.95 eV This modification notably enhanced the material's light-harvesting capabilities, making it more effective for photovoltaic applications. Fourier-transform infrared (FTIR) spectroscopy highlighted distinct Cu-O vibrations and notable changes in hydroxyl and CO bonding, signifying alterations in surface chemistry and bonding structures. These structural and chemical modifications contribute to the material's enhanced performance. Photoluminescence (PL) analysis revealed a pronounced green emission at 530 nm under 0.4 M Ga doping, linked to changes in radiative and non-radiative recombination processes. Indeed, Ga doping enhances the structural and optical properties of CuO thin films, including tailored bandgap energy, improved crystallinity, and superior optical absorption. These improvements make Ga-doped CuO thin films promising to predict solar cells and photocatalytic applications technologies, boosting the efficiency of photovoltaic and photoluminescence systems.