Patent ID: 9551077
Date: 2017-01-24
CPC Classifications: B01J,C07C,C25B,Y02P

Claim:
1. A photoelectrode used to reduce carbon dioxide by light energy, comprising a region including a nitride semiconductor layer in which a first aluminum gallium nitride layer, composition formula of which is Al x Ga l-x N, where a value of x representing a composition ratio of Al is a fixed value that satisfies 0<x≦0.25, a second aluminum gallium nitride layer, composition formula of which is Al y Ga l-y N, where a value of y representing a composition ratio of Al is a variable value that satisfies 0≦y≦x, and a gallium nitride layer, composition formula of which is GaN, are laminated in this order from a surface of the photoelectrode to be irradiated with light, wherein the value of y in the second aluminum gallium nitride layer changes, without any increase, from an interface with the first aluminum gallium nitride layer toward an interface with the gallium nitride layer.