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Title: Simultaneous enhancement of photovoltage and charge transfer in Cu{sub 2}O-based photocathode using buffer and protective layers

Abstract

Coating n-type buffer and protective layers on Cu{sub 2}O may be an effective means to improve the photoelectrochemical (PEC) water-splitting performance of Cu{sub 2}O-based photocathodes. In this letter, the functions of the buffer layer and protective layer on Cu{sub 2}O are examined. It is found that a Ga{sub 2}O{sub 3} buffer layer can form a buried junction with Cu{sub 2}O, which inhibits Cu{sub 2}O self-reduction as well as increases the photovoltage through a small conduction band offset between the two semiconductors. The introduction of a TiO{sub 2} thin protective layer not only improves the stability of the photocathode but also enhances the electron transfer from the photocathode surface into the electrolyte, thus resulting in an increase in photocurrent at positive potentials. These results show that the selection of overlayers with appropriate conduction band positions provides an effective strategy for obtaining a high photovoltage and high photocurrent in PEC systems.

Authors:
;  [1]; ; ;  [2]; ;  [3]
  1. School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)
  2. Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)
  3. Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)
Publication Date:
OSTI Identifier:
22594485
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BUFFERS; CONNECTORS; COPPER OXIDES; ELECTROLYTES; ELECTRON TRANSFER; GALLIUM OXIDES; LAYERS; N-TYPE CONDUCTORS; PHOTOCATHODES; PHOTOCURRENTS; SURFACES; TITANIUM OXIDES

Citation Formats

Li, Changli, Delaunay, Jean-Jacques, E-mail: jean@mech.t.u-tokyo.ac.jp, Hisatomi, Takashi, Watanabe, Osamu, Domen, Kazunari, Nakabayashi, Mamiko, and Shibata, Naoya. Simultaneous enhancement of photovoltage and charge transfer in Cu{sub 2}O-based photocathode using buffer and protective layers. United States: N. p., 2016. Web. doi:10.1063/1.4959098.
Li, Changli, Delaunay, Jean-Jacques, E-mail: jean@mech.t.u-tokyo.ac.jp, Hisatomi, Takashi, Watanabe, Osamu, Domen, Kazunari, Nakabayashi, Mamiko, & Shibata, Naoya. Simultaneous enhancement of photovoltage and charge transfer in Cu{sub 2}O-based photocathode using buffer and protective layers. United States. doi:10.1063/1.4959098.
Li, Changli, Delaunay, Jean-Jacques, E-mail: jean@mech.t.u-tokyo.ac.jp, Hisatomi, Takashi, Watanabe, Osamu, Domen, Kazunari, Nakabayashi, Mamiko, and Shibata, Naoya. 2016. "Simultaneous enhancement of photovoltage and charge transfer in Cu{sub 2}O-based photocathode using buffer and protective layers". United States. doi:10.1063/1.4959098.
@article{osti_22594485,
title = {Simultaneous enhancement of photovoltage and charge transfer in Cu{sub 2}O-based photocathode using buffer and protective layers},
author = {Li, Changli and Delaunay, Jean-Jacques, E-mail: jean@mech.t.u-tokyo.ac.jp and Hisatomi, Takashi and Watanabe, Osamu and Domen, Kazunari and Nakabayashi, Mamiko and Shibata, Naoya},
abstractNote = {Coating n-type buffer and protective layers on Cu{sub 2}O may be an effective means to improve the photoelectrochemical (PEC) water-splitting performance of Cu{sub 2}O-based photocathodes. In this letter, the functions of the buffer layer and protective layer on Cu{sub 2}O are examined. It is found that a Ga{sub 2}O{sub 3} buffer layer can form a buried junction with Cu{sub 2}O, which inhibits Cu{sub 2}O self-reduction as well as increases the photovoltage through a small conduction band offset between the two semiconductors. The introduction of a TiO{sub 2} thin protective layer not only improves the stability of the photocathode but also enhances the electron transfer from the photocathode surface into the electrolyte, thus resulting in an increase in photocurrent at positive potentials. These results show that the selection of overlayers with appropriate conduction band positions provides an effective strategy for obtaining a high photovoltage and high photocurrent in PEC systems.},
doi = {10.1063/1.4959098},
journal = {Applied Physics Letters},
number = 3,
volume = 109,
place = {United States},
year = 2016,
month = 7
}
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