Solar Hydrogen Production with Metal/III–V Semiconductor Junction Monolithically Integrated on Si
GaAs is an excellent candidate for high‐performance photoelectrochemical water splitting due to its appropriate band‐edge and bandgap energies, as well as its excellent transport properties. The most significant limitations of GaAs for photoelectrochemical applications are its instability against corrosion, the high substrate cost, and the huge overpotentials required for triggering water electrolysis. The monolithic epitaxial integration of GaAs thin films directly on the Earth‐abundant Si fundamentally limits the costs associated with the substrate fabrication. Herein, photocathodes made of 1 µm thick GaAs layers epitaxially grown on p‐doped Si substrates are developed and their performances are compared to those of bare p‐doped GaAs electrodes. Sulfur passivation and standard interfacing with Pt catalyst are applied and analyzed for both series of photocathodes. A massive onset potential shift of 0.63 V is demonstrated for GaAs/Si photocathodes after electroless Pt deposition and sulfur passivation, reaching an onset potential of 0.4 V versus the reversible hydrogen electrode. The stability of the Pt/GaAs/Si photocathode is finally assessed over more than 112 h. These findings are essential for further development toward the fabrication of cost‐efficient and stable unassisted photoelectrochemical cells for green hydrogen production.
Authors
- Ludovic Largeau (ORCID: https://orcid.org/0000-0002-8566-9648)
- Angus Rockett (ORCID: https://orcid.org/0000-0001-9759-8421)
- Bruno Fabre (ORCID: https://orcid.org/0000-0002-0488-7812)
- Yoan Léger (ORCID: https://orcid.org/0000-0003-0807-0049)
- Sylvie Harel (ORCID: https://orcid.org/0000-0002-1427-9378)
- K. Xerxes Steirer (ORCID: https://orcid.org/0000-0001-6137-2105)
- G. Patriarche (ORCID: https://orcid.org/0000-0002-3917-2470)
- Nicolas Bertru (ORCID: https://orcid.org/0000-0002-4378-260X)
- Gabriel Loget (ORCID: https://orcid.org/0000-0003-4809-5013)
- Christophe Levallois (ORCID: https://orcid.org/0000-0001-5832-0769)
- Charles Cornet (ORCID: https://orcid.org/0000-0002-1363-7401)
- Hanh Vi Le
- Rozenn Bernard (ORCID: https://orcid.org/0000-0001-9312-5037)
- Antoine Létoublon (ORCID: https://orcid.org/0000-0002-3655-5943)
- Fauzia Jabeen (ORCID: https://orcid.org/0000-0002-5918-9405)
- Sylvain Febvre
- Karine Tavernier
- Tony Rohel
- Julie Le Pouliquen
- Bienvenu Boulingui Koumba
- Fatima Merhi (ORCID: https://orcid.org/0009-0003-4854-8323)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Université de Bordeaux (FR)
- Colorado School of Mines (US)
- Université Paris-Saclay (FR)
- Institut National des Sciences Appliquées de Rennes (FR)
- Institut des Sciences Moléculaires (FR)
- Institut des Sciences Chimiques de Rennes (FR)
- Institut des Matériaux Jean Rouxel (FR)
- Centre de Nanosciences et de Nanotechnologies (FR)
- Institut de Physique de Rennes (FR)
- Institut Polytechnique de Bordeaux (FR)
- Université de Rennes (FR)
Publication Details
- Journal
- ChemElectroChem
- Published
- 2025-10-10
- DOI
- https://doi.org/10.1002/celc.202500251
- Primary Topic
- Silicon and Solar Cell Technologies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Equipex
- Agence Nationale de la Recherche
- Région Bretagne