ひずみ制御が可能にする高圧相半導体材料の実現

抄録

The large band gap of most metal oxides restricts their photocatalytic activity to the ultraviolet (UV) range of the solar spectrum. Almost 5% UV is present in the whole solar spectrum so that designing metal oxide semiconductors with the capability of absorbing visible light is long attempted. The large band gap of metal oxides can be reduced by methods like doping, however, photocatalytic activity is not necessarily enhanced due to the defect-induced carrier recombination losses. In recent years, we have focused on the high-pressure phases of wide band gap semiconductors, which theoretically possess narrow band gaps, being able to absorb visible light. In this review, high-pressure phases of well-known semiconductors like TiO₂, ZnO, and Y₂O₃ have been stabilized by applying a severe plastic deformation method, and their photocatalytic properties are evaluated.