APPLIED JOURNAL OF PHYSICAL SCIENCE
Integrity Research Journals
ISSN: 2756-6684
Model: Open Access/Peer Reviewed
DOI: 10.31248/AJPS
Start Year: 2018
Email: ajps@integrityresjournals.org
Cuprous oxide (Cu₂O) photoelectrodes for photoelectrochemical solar cells: Materials properties, fabrication techniques and device architectures: A Review
https://doi.org/10.31248/AJPS2026.139 | Article Number: DA1EE6FC1 | Vol.7 (4) - August 2026
Received Date: 21 March 2026 | Accepted Date: 08 May 2026 | Published Date: 30 August 2026
Authors: I. Aliyu* , Ayuba M. , I. M. Murtala , I. I. Idowu , A. A. Safana , U. M. Dankawu and N. Yunusa
Keywords: morphology, Electrodeposition, photoelectrochemical (PEC), photoelectrode, solar cells, sputtering, thermal oxidation.
The increasing global demand for sustainable energy has intensified research into solar-driven fuel generation technologies. Photoelectrochemical (PEC) solar cells represent a promising pathway for direct conversion of solar energy into chemical fuels such as hydrogen through water splitting. Among various semiconductor materials investigated for PEC applications, cuprous oxide (Cu₂O) has attracted significant attention owing to its suitable direct band gap (~2.0 eV), high absorption coefficient in the visible spectrum, earth abundance, and low toxicity. However, the practical deployment of Cu₂O-based PEC devices remains limited by challenges including photocorrosion, short minority-carrier diffusion lengths, and defect-mediated recombination. This review provides a comprehensive overview of Cu₂O as a photoelectrode material for PEC solar cells. The fundamental electronic and optical properties of Cu₂O are discussed together with intrinsic defect chemistry and charge transport characteristics relevant to PEC operation. Various fabrication techniques for Cu₂O thin films such as immersion deposition, boiling-assisted deposition, electrodeposition, thermal oxidation, and sputtering are critically reviewed with emphasis on their influence on film morphology, crystallinity, and electronic properties. In addition, different PEC device architectures such as regenerative PEC cells, photocatalytic PEC cells, single-photoelectrode systems, and tandem configurations are examined. Finally, key strategies for improving the performance and stability of Cu₂O photoelectrodes, including surface passivation, catalyst integration, and heterojunction engineering, are highlighted. The review concludes with perspectives on future research directions aimed at enabling efficient and durable Cu₂O-based PEC solar energy conversion systems.
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