This title appears in the Scientific Report : 2016 

High-Efficiency InP-Based Photocathode for Hydrogen Production by Interface Energetics Design and Photon Management
Gao, Lu (Corresponding author)
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. (Corresponding author) / Hensen, Emiel J. M. (Corresponding author)
Grundlagen der Elektrochemie; IEK-9
Advanced functional materials, 26 (2016) 5, S. 679–686
Weinheim Wiley-VCH 2016
10.1002/adfm.201503575
Journal Article
Electrochemical Storage
Please use the identifier: http://dx.doi.org/10.1002/adfm.201503575 in citations.
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 TiO2 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.