Hydrothermally Grown CuO Thin Films for Optoelectronic Applications: Optical and Electrical Analysis

Abstract

Cupric oxide (CuO) thin films were deposited using a simple and cost-effective hydrothermal technique and examined for their optoelectronic suitability. The optical properties were studied using UV–Visible spectroscopy, which revealed significant absorption in the visible and near-infrared regions. The optical band gap, evaluated using the Tauc approach, was estimated to be 3.58 eV. The observed widening of the band gap compared to bulk CuO is attributed to nanoscale effects, defect-related localized states, and growth conditions associated with the hydrothermal process. Electrical characterization showed a linear current–voltage response, indicating ohmic conduction and good electrical contact. These findings demonstrate that hydrothermally synthesized CuO thin films possess favorable optical transparency and stable electrical transport, making them promising candidates for optoelectronic device applications.