Simultaneous enhancement of photovoltage and charge transfer in Cu{sub 2}O-based photocathode using buffer and protective layers
- School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)
- Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)
- Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)
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.
- OSTI ID:
- 22594485
- Journal Information:
- Applied Physics Letters, Vol. 109, Issue 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Wide Band Gap Chalcopyrite Photoelectrodes for Direct Water Splitting (Final Technical Report)
Investigation of Electron Extraction and Protection Layers on Cu2O Photocathodes