570 mV photovoltage, stabilized n-Si/CoOx heterojunction photoanodes fabricated using atomic layer deposition
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis (JCAP); California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Engineering and Applied Science, Dept. of Applied Physics and Materials Science
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis (JCAP)
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis (JCAP); California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Chemistry and Chemical Engineering
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis (JCAP); California Inst. of Technology (CalTech), Pasadena, CA (United States). Kavli Nanoscience Inst.
- California Inst. of Technology (CalTech), Pasadena, CA (United States). Joint Center for Artificial Photosynthesis (JCAP); California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Chemistry and Chemical Engineering; California Inst. of Technology (CalTech), Pasadena, CA (United States). Beckman Inst. and Molecular Materials Research Center; California Inst. of Technology (CalTech), Pasadena, CA (United States). Kavli Nanoscience Inst.
Heterojunction photoanodes, consisting of n-type crystalline Si(100) substrates coated with a thin ~50 nm film of cobalt oxide fabricated using atomic-layer deposition (ALD), exhibited photocurrent-onset potentials of -205 ± 20 mV relative to the formal potential for the oxygen-evolution reaction (OER), ideal regenerative solar-to-O2(g) conversion efficiencies of 1.42 ± 0.20%, and operated continuously for over 100 days (~2500 h) in 1.0 M KOH(aq) under simulated solar illumination. The ALD CoOx thin film: (i) formed a heterojunction with the n-Si(100) that provided a photovoltage of 575 mV under 1 Sun of simulated solar illumination; (ii) stabilized Si photoanodes that are otherwise unstable when operated in aqueous alkaline electrolytes; and, (iii) catalyzed the oxidation of water, thereby reducing the kinetic overpotential required for the reaction and increasing the overall efficiency relative to electrodes that do not have an inherently electrocatalytic coating. The process provides a simple, effective method for enabling the use of planar n-Si(100) substrates as efficient and durable photoanodes in fully integrated, photovoltaic-biased solar fuels generators.
- Research Organization:
- California Institute of Technology (CalTech), Pasadena, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); Gordon and Betty Moore Foundation
- Grant/Contract Number:
- SC0004993
- OSTI ID:
- 1436118
- Journal Information:
- Energy & Environmental Science, Vol. 9, Issue 3; ISSN 1754-5692
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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