Photoelectrochemical cell and energy system using same

Abstract

A photoelectrochemical cell () includes: a semiconductor electrode () including a conductor () and semiconductor layers () disposed on the conductor (); a counter electrode () connected electrically to the conductor (); an electrolyte () in contact with surfaces of the semiconductor layer () and the counter electrode (); and a container () accommodating the semiconductor electrode (), the counter electrode () and the electrolyte (). A band edge level Eof a conduction band, a band edge level Eof a valence band, and a Fermi level Ein a surface near-field region of the semiconductor layer, and a band edge level Eof a conduction band, a band edge level Eof a valence band, and a Fermi level Ein a junction plane near-field region of the semiconductor layer with the conductor satisfy, relative to a vacuum level, E−E>E−E, E−E<E−E, E>−4.44 eV, and E<−5.67 eV. The Fermi level Ein the surface near-field region of the semiconductor layer and the Fermi level Ein the junction plane near-field region of the semiconductor layer with the conductor satisfy, relative to the vacuum level, −5.67 eV<E<−4.44 eV and −5.67 eV<E<−4.44 eV, respectively.