TY - JOUR
T1 - Tin Oxide as a Protective Heterojunction with Silicon for Efficient Photoelectrochemical Water Oxidation in Strongly Acidic or Alkaline Electrolytes
AU - Moreno-Hernandez, Ivan A.
AU - Brunschwig, Bruce S.
AU - Lewis, Nathan S.
N1 - Funding Information:
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.
Publisher Copyright:
© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/8/27
Y1 - 2018/8/27
N2 - 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 (SnOx) layers applied to n-Si wafers after forming a thin chemically oxidized SiOx layer can passivate the Si surface while producing ≈620 mV photovoltage under 100 mW cm−2 of simulated sunlight. The SnOx 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 H2SO4(aq). Ideal regenerative solar-to-O2(g) efficiencies of 4.1% and 3.7%, respectively, are obtained in 1.0 m KOH(aq) with Ni or in 1.0 m H2SO4(aq) with Pt/IrOx 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 H2SO4(aq).
AB - 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 (SnOx) layers applied to n-Si wafers after forming a thin chemically oxidized SiOx layer can passivate the Si surface while producing ≈620 mV photovoltage under 100 mW cm−2 of simulated sunlight. The SnOx 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 H2SO4(aq). Ideal regenerative solar-to-O2(g) efficiencies of 4.1% and 3.7%, respectively, are obtained in 1.0 m KOH(aq) with Ni or in 1.0 m H2SO4(aq) with Pt/IrOx 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 H2SO4(aq).
KW - heterojunctions
KW - photoanodes
KW - photoelectrochemistry
KW - water oxidation
KW - water splitting
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U2 - 10.1002/aenm.201801155
DO - 10.1002/aenm.201801155
M3 - Article
AN - SCOPUS:85050873377
VL - 8
JO - Advanced Energy Materials
JF - Advanced Energy Materials
SN - 1614-6832
IS - 24
M1 - 1801155
ER -