GROUP III/V NITRIDE SEMICONDUCTOR, PHOTOCATALYST SEMICONDUCTOR ELEMENT, PHOTOCATALYTIC REDOX REACTION APPARATUS, AND PHOTOELECTROCHEMICAL REACTION EXECUTION METHOD

摘要

This invention provides a group III/V nitride semiconductor, which causes a redox reaction with high phototransformation efficiency upon light irradiation, a photocatalyst semiconductor element, a photocatalytic redox reaction apparatus, and a photoelectrochemical reaction execution method. The group III/V nitride semiconductor is characterized in that the full width at half maximum of an X-ray rocking curve for the catalytic reaction face is not more than 400 arcsec and the carrier concentration in a surface layer part having the catalytic reaction face is not less than 1.5 × 10<SUP>16</SUP> cm<SUP>-3</SUP> and not more than 3.0 × 10<SUP>18</SUP> cm<SUP>-3</SUP>. The photocatalyst semiconductor element is characterized in that the above group III/V nitride semiconductor is stacked on a substrate. The photocatalytic redox reaction apparatus is characterized in that one of a pair of electrolysis electrodes which are in contact with an electrolysis solution for electrical connection to each other is formed of the above group III/V nitride semiconductor, and, upon exposure of light to the catalytic reaction face constituting the group III/V nitride semiconductor, an oxidation reaction or a reduction reaction takes place in the catalytic reaction face.