Structural, Optical, and Electrical Properties of Gd‐Doped CuO/Cu ₂ O/n‐Si Heterojunctions

In this study, undoped and Gd‐doped CuO/Cu ₂ O thin films were fabricated on soda–lime glass and n‐type Si substrates using the spin‐coating technique to investigate the influence of Gd incorporation on the structural, optical, and electrical behavior of CuO/Cu ₂ O‐based heterojunction devices. Different Gd concentrations were employed to evaluate the role of rare‐earth doping on phase formation, optical response, and charge transport characteristics of the resulting thin films and heterojunction diodes. The structural properties of the films were examined by X‐ray diffraction analysis, while the optical behavior was investigated using UV–vis spectroscopy. In addition, the electrical characteristics of the fabricated heterojunctions were analyzed through current–voltage ( I – V ) and capacitance–voltage ( C – V ) measurements under dark and illuminated conditions. The study aims to provide a comprehensive understanding of how Gd incorporation modifies the interfacial and electronic properties of CuO/Cu ₂ O/n‐Si heterojunction structures for potential optoelectronic device applications.