Optimizing CuSe Thin Film Morphology and Performance in Water Splitting Applications Using Chemical Vapor Deposition Techniques

Abstract

The global quest for sustainable and clean energy has heightened research efforts in photoelectrochemical (PEC) water splitting for hydrogen production. Among semiconductor materials, copper selenide (CuSe) has emerged as a promising photocathode candidate due to its narrow direct bandgap (1.5–1.7 eV), high photoconductivity, and composition that is both earth-abundant and non-toxic. The efficiency of CuSe in PEC systems is significantly affected by its thin film morphology, crystal quality, and interface properties, which are particularly sensitive to synthesis routes and growth parameters. Chemical vapor deposition (CVD) provides distinct advantages, including atomic-level control over film thickness, stoichiometry, and crystalline orientation, rendering it an optimal method for engineering CuSe thin films with superior optoelectronic properties.

This review systematically examines recent developments (2020–2025) in the synthesis, morphological tuning, and performance enhancement of CuSe thin films for water splitting applications, with an emphasis on CVD techniques. This paper initially delineates the essential physical and chemical properties of CuSe that support its photocatalytic behavior. This evaluation examines different deposition methods, highlighting the mechanistic and structural benefits of CVD in comparison to solution-based techniques. A review of key literature highlights the impact of various CVD parameters, specifically precursor type, deposition temperature, and ambient pressure, on the nucleation, growth, and final architecture of CuSe thin films.

The relationship between morphology and PEC performance is critically examined, focusing on the impact of nanostructured features such as nanorods, porous layers, and heterojunction interfaces on charge transport and light absorption. The discussion encompasses characterization techniques, including XRD, UV-Vis spectroscopy, PL, and EIS, focusing on their relevance to material quality and catalytic activity. The review identifies significant challenges, including surface oxidation, carrier recombination, and the absence of scalable, high-purity CVD processes for CuSe. Future directions include the integration synthesis, hybrid tandem systems, and scalable reactor designs. This review consolidates and analyzes current findings to establish a research roadmap for the development of CuSe-based photoelectrodes in next-generation hydrogen fuel technologies.