PHOTOELECTROCHEMICAL CELL AND ENERGY SYSTEM USING SAME

摘要

A photoelectrochemical cell (100) includes: a semiconductor electrode (120) including a conductor (121) and semiconductor layers (122, 123) disposed on the conductor (121); a counter electrode (130) connected electrically to the conductor (121); an electrolyte (140) in contact with surfaces of the semiconductor layer (123) and the counter electrode (130); and a container (110) accommodating the semiconductor electrode (120), the counter electrode (130) and the electrolyte (140). A band edge level Ecs of a conduction band, a band edge level Evs of a valence band, and a Fermi level E FS in a surface near-field region of the semiconductor layer, and a band edge level E CJ of a conduction band, a band edge level E VJ of a valence band, and a Fermi level E FJ in a junction plane near-field region of the semiconductor layer with the conductor satisfy, relative to a vacuum level, E CS - E FS > E CJ - E FJ , E FS - Evs < E FJ - E VJ , E CJ > -4.44 eV, and Evs < -5.67 eV The Fermi level E FS in the surface near-field region of the semiconductor layer and the Fermi level E FJ in the junction plane near-field region of the semiconductor layer with the conductor satisfy, relative to the vacuum level, -5.67 eV < E FS < -4.44 eV and -5.67 eV < E FJ < -4.44 eV, respectively.