Chemical and electronic structure analysis of a SrTiO3 (001)/p-Ge (001) hydrogen evolution photocathode. (19th March 2018)

• Record Type: Journal Article
• Authors: Stoerzinger, Kelsey A.; Du, Yingge; Spurgeon, Steven R.; Wang, Le; Kepaptsoglou, Demie; Ramasse, Quentin M.; Crumlin, Ethan J.; Chambers, Scott A.
• Is Part Of: MRS communications. Volume 8:Number 2(2018)
• Page Start: 446
• Page End: 452
• Publication Date: 2018-03-19
• Subjects: Materials -- Periodicals; 620.11
• DOI: 10.1557/mrc.2018.38
• Languages: English
• ISSNs: 2159-6859

Abstract

Abstract: Abstract : Germanium is a small-gap semiconductor that efficiently absorbs visible light, resulting in photoexcited electrons predicted to be sufficiently energetic to reduce H2 O for H2 gas evolution. In order to protect the surface from corrosion and prevent surface charge recombination in contact with aqueous pH 7 electrolyte, we grew epitaxial SrTiO3 layers of different thicknesses on p -Ge (001) surfaces. Four-nanometer SrTiO3 allows photogenerated electrons to reach the surface and evolve H2 gas, while 13 nm SrTiO3 blocks these electrons. Ambient pressure x-ray photoelectron spectroscopy indicates that the surface readily dissociates H2 O to form OH species, which may impact surface band bending.