https://doi.org/10.1140/epjs/s11734-026-02274-2
Regular Article
Structural, optical, and photoelectrochemical characterization of magnetron-sputtered GaN films on p-Si for solar water splitting
1
State Key Laboratory of Crystal Materials, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, 300384, Tianjin, China
2
Tianjin Zhongtian Haisheng Environmental Protection Technology Co., LTD, 300384, Tianjin, China
a
This email address is being protected from spambots. You need JavaScript enabled to view it.
b
This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
29
December
2025
Accepted:
13
March
2026
Published online:
30
March
2026
Abstract
This work demonstrates the deposition of GaN thin films on p-type Si substrate via magnetron sputtering for photoelectrochemical (PEC) water splitting. By varying the N2/Ar flow ratio, we systematically investigated its effects on microstructure, composition, and PEC performance. The results indicate that lower N2/Ar ratios promote larger grain sizes due to enhanced adatom surface mobility and limited nucleation sites. Film stoichiometry exhibits a non-monotonic trend: Ar-rich conditions yield Ga-rich films (Ga 64.61%), balanced plasma produces near-stoichiometric GaN (Ga 58.64%), while N2-rich conditions lead to slight Ga enrichment (Ga 61.74%). The sample deposited at a balanced N2/Ar ratio (1:1) achieves the highest photocurrent density, reaching − 42 mA/cm2 at − 2.5 V vs RHE. This corresponds to a 3.2‑fold improvement compared to the bare p‑Si substrate, which can be attributed to the sample’s enhanced light absorption and the built‑in electric field formed at the GaN/Si interface that promotes the separation of photogenerated charge carriers. Besides, the optimized electrode also shows excellent stability over 11,000 s. These findings highlight magnetron sputtering as a scalable approach for efficient GaN-based photoelectrodes, with reactive gas atmosphere as a key tuning parameter.
Copyright comment Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
© The Author(s), under exclusive licence to EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature 2026
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
