An efficient and clean method of doping transition metal oxides (TMOs) with hole carriers is presented. We have fabricated oxide heterostructures made of various TMO thin films grown on n-type titanium oxide substrates, and measured in-plane resistance under ultraviolet light irradiation. It is shown that the resistance of the insulating TMOs is reduced significantly with increasing light irradiance, as a result of photoinduced hole carrier injection from the titanium oxide substrates. A generic band structure for the heterojunctions is proposed, in which a large potential slope and a small barrier exist near the interface for photoinduced holes and electrons in the titanium oxides, respectively. This photocarrier injection (PCI) technique would provide us with a useful method to achieve the external control of hole carrier density in TMOs.
- Manganese perovskite
- Photocarrier injection
- Transition metal oxides
ASJC Scopus subject areas
- General Physics and Astronomy