Cobalt Doping Effects on Cu₂O Thin Films: A Sol-Gel Approach for Enhanced Conductivity and Crystallinity
Abstract
In this study, cobalt-doped Cu₂O thin films were synthesized using the sol-gel method and characterized to investigate the effects of cobalt doping on their structural, morphological, and electrical properties. Copper (II) and cobalt (II) nitrates were dissolved in ethanol, and glacial acetic acid was used as a stabilizing agent. The films were deposited onto quartz substrates by spin-coating and thermally annealed at 400°C for 2 hours to promote crystallization. The structural characteristics of the films were analysed using Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD). FTIR spectra showed that cobalt doping led to shifts in the Cu–O bond region and an increase in the intensity of certain peaks, indicating changes in bonding structures and lattice modifications. XRD patterns revealed that increasing cobalt concentrations caused peak broadening and slight shifts in the peak positions, suggesting lattice distortions and the formation of new phases at higher doping levels. Morphological studies using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) showed that cobalt doping improved surface uniformity and reduced surface roughness up to an optimal concentration of 3%, beyond which grain agglomeration occurred. Electrical conductivity measurements indicated a significant improvement in conductivity, with a two-order magnitude increase at 3% Co doping. The enhancement in conductivity is attributed to Co²⁺ ions acting as donor impurities, increasing carrier concentration and mobility. However, at 5% Co doping, a slight decrease in conductivity was observed due to dopant clustering and defect scattering. This study highlights the potential of cobalt-doped Cu₂O thin films for applications in optoelectronics, catalysis, and energy storage
How to Cite
Rinka Tuteja, Vikram Singh, "Cobalt Doping Effects on Cu₂O Thin Films: A Sol-Gel Approach for Enhanced Conductivity and Crystallinity", Vol. 3, Issue 2, 30-05-2025, pp. 33-49.
