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High‐Efficiency InP‐Based Photocathode for Hydrogen Production by Interface Energetics Design and Photon Management
Author(s) -
Gao Lu,
Cui Yingchao,
Vervuurt Rene H. J.,
van Dam Dick,
van Veldhoven Rene P. J.,
Hofmann Jan P.,
Bol Ageeth A.,
Haverkort Jos E. M.,
Notten Peter H. L.,
Bakkers Erik P. A. M.,
Hensen Emiel J. M.
Publication year - 2016
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201503575
Subject(s) - photocathode , materials science , energetics , interface (matter) , photon , hydrogen production , optoelectronics , production (economics) , hydrogen , nanotechnology , engineering physics , photochemistry , optics , nuclear physics , physics , thermodynamics , composite material , chemistry , quantum mechanics , electron , macroeconomics , capillary number , capillary action , economics
The solar energy conversion efficiency of photoelectrochemical (PEC) devices is usually limited by poor interface energetics, limiting the onset potential, and light reflection losses. Here, a three‐pronged approach to obtain excellent performance of an InP‐based photoelectrode for water reduction is presented. First, a buried p–n + junction is fabricated, which shifts the valence band edge favorably with respect to the hydrogen redox potential. Photoelectron spectroscopy substantiates that the shift of the surface photovoltage is mainly determined by the buried junction. Second, a periodic array of InP nanopillars is created at the surface of the photoelectrode to substantially reduce the optical reflection losses. This device displays an unprecedented photocathodic power‐saved efficiency of 15.8% for single junction water reduction. Third, a thin TiO 2 protection layer significantly increases the stability of the InP‐based photoelectrode. Careful design of the interface energetics based on surface photovoltage spectroscopy allows obtaining a PEC cell with stable record performance in water reduction.