Tin Oxide as a Protective Heterojunction with Silicon for Efficient Photoelectrochemical Water Oxidation in Strongly Acidic or Alkaline Electrolytes
Abstract
Photoelectrodes without a p–n junction are often limited in efficiency by charge recombination at semiconductor surfaces and slow charge transfer to electrocatalysts. This study reports that tin oxide (SnO_x) layers applied to n‐Si wafers after forming a thin chemically oxidized SiO_x layer can passivate the Si surface while producing ≈620 mV photovoltage under 100 mW cm^(−2) of simulated sunlight. The SnO_x layer makes ohmic contacts to Ni, Ir, or Pt films that act as precatalysts for the oxygen‐evolution reaction (OER) in 1.0 m KOH(aq) or 1.0 m H_2SO_4(aq). Ideal regenerative solar‐to‐O_2(g) efficiencies of 4.1% and 3.7%, respectively, are obtained in 1.0 m KOH(aq) with Ni or in 1.0 m H2_SO_4(aq) with Pt/IrO_x layers as OER catalysts. Stable photocurrents for >100 h are obtained for electrodes with patterned catalyst layers in both 1.0 m KOH(aq) and 1.0 m H_2SO_4(aq).
Additional Information
© 2018 WILEY‐VCH. Received: April 16, 2018. Revised: May 26, 2018. Version of Record online: 01 July 2018. This work was supported through the Office of Science of the U.S. Department of Energy (DOE) under award no. DE‐SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub. I.A.M.‐H. acknowledges a National Science Foundation Graduate Research Fellowship under Grant No. DGE‐1144469. The authors thank C. Garland for assistance with transmission‐electron microscopy. The authors declare no conflict of interest.Attached Files
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Additional details
- Eprint ID
- 87651
- DOI
- 10.1002/aenm.201801155
- Resolver ID
- CaltechAUTHORS:20180709-131016014
- Department of Energy (DOE)
- DE-SC0004993
- NSF Graduate Research Fellowship
- DGE‐1144469
- Created
-
2018-07-09Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- JCAP