【Device Papers】Solution-processed Ga₂O₃ overlayers for improved electron extraction in CuBi₂O₄ water-reduction photocathodes

      Researchers from the Jinling Institute of Technology have published a dissertation titled "Solution-processed Ga₂O₃ overlayers for improved electron extraction in CuBi₂O₄ water-reduction photocathodes" in Materials Science in Semiconductor Processing.

Abstract

      The establishment of p‒n junction is pivotal in enhancing the efficiency of solar water splitting. Nevertheless, the poor conductivity and inadequate charge separation frequently lead to a pronounced discrepancy between their actual photoelectrochemical (PEC) performance and their theoretically predicted potential. In this study, we develop a post-treatment strategy to construct a CuBi₂O₄/Ga₂O₃ buried p‒n junction. Through an integrated analysis of physical characterization and electrochemical testing, it has been established that the incorporation of Ga₂O₃ substantially mitigates carrier recombination at the CuBi₂O₄ surface, facilitates the transport of photogenerated electron-hole pairs, and enhances charge separation efficiency. Consequently, this approach leads to a marked improvement in the PEC water splitting performance. The optimized CuBi₂O₄/Ga₂O₃ photocathode achieves a photocurrent of −0.324 mA cm⁻², representing an 18.2 % enhancement compared to that of pure CuBi₂O₄.

DOI：

https://doi.org/10.1016/j.mssp.2025.110216