Hierarchically Structured CdO/por-CdS/CdS Heterojunctions via Electrochemical Processing for Enhanced Solar Conversion

This poster reports the fabrication and characterization of CdO/por-CdS/CdS heterostructures designed to improve charge separation and light management for solar-energy and photocatalytic applications. A two-step electrochemical route is employed: (i) anodic electrochemical etching of CdS (5% HCl, 5 V, Xe lamp illumination) to form a porous buffer layer that mitigates lattice-mismatch and increases internal surface area; (ii) cathodic deposition in an aqueous electrolyte followed by oxygen annealing (150 °C, 20 min) to obtain a CdO top layer. Morphology (SEM) reveals a three-dimensional globular/porous architecture; EDX confirms Cd, S, and O elemental composition; XRD indicates predominantly crystalline wurtzite CdS with minor cadmium-oxide phases; Raman spectra show the characteristic CdS phonon modes with additional low-intensity features attributed to defects/surface effects. The hierarchical interface is argued to reduce recombination through light trapping and improved charge transport. The method is scalable and industry-friendly, offering a viable pathway to integrate the heterostructures into photovoltaic and photocatalytic devices. Funding: Supported by the National Research Foundation of Ukraine (Project No. 0124U002023 “Design and research of oxide heterostructures for portable solar cells”). Notes: Poster includes representative SEM images, EDX spectrum, XRD and Raman analyses. Underlying measurement data are available upon reasonable request