β-Ga2O3 Single Crystal as a Photoelectrode for Water Splitting

• DOI: 10.7567/jjap.52.111102
• Publication Date: 2013-11-05T02:41:37Z
• Authors: Takayoshi Oshima; Kenichi Kaminaga; Hisanori Mashiko; Akira Mukai; Kohei Sasaki; Takekazu Masui; Akito Kuramata; Shigenobu Yamakoshi; Akira Ohtomo
• Keywords: Photocurrent; Photon energy; Crystal (programming language); Photoconductivity; Absorption edge; Stoichiometry; Photoelectrochemistry

We report the photoelectrode properties of an n-type β-Ga 2 O 3 single crystal in aqueous solutions. The conduction and valence band-edge potentials were found to be 1.1 V higher 2.5 lower than H + /H redox potentials, respectively. Photocurrent drastically increased as photogenerated carriers excited at a photon energy fundamental absorption edge 4.7 eV. incident photon-to-current conversion efficiency was 36% 5.2 Gaseous oxygen hydrogen evolved from Pt counter electrode, stoichiometric water splitting demonstrated by applying external bias 1 V.