Biosynthesis and Fabrication of Copper Oxide Thin Films as a P-Type Semiconductor for Solar Cell Applications

Abstract

This study aimed to synthesize copper oxide (CuO) thin films using an eco-friendly green synthetic approach. A sol-gel spin coating technique was employed for the synthesis of the CuO thin film using Allium cepa as a reducing agent. The fabricated CuO thin film was investigated using the Fourier Transform-Infrared (FTIR) spectroscopy, Ultraviolet-visible spectra studies (UV-Vis), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and the Four-Point Probe measurement. The SEM micrographs revealed that the particles were spherically shaped, while the EDX analysis revealed that the CuO thin film was composed of copper and oxygen elements. Furthermore, the XRD analysis confirmed the monoclinic crystalline structure of the CuO thin film, while the FTIR spectroscopy investigated the chemical bonds formed during the production process. Contrarily, the UV-Vis spectroscopy reported a strong absorption of the film at the visible spectra with an estimated optical energy band gap of 1.48 eV. The electrical analysis, however, disclosed that the synthesized thin film portrayed good semiconducting behaviors.