Photocarrier-injected electronic structure of v O₂/Ti O ₂: Nb

We study the effect of photocarrier injection on the electronic structure of V O2 Ti O2: Nb thin films using photoemission spectroscopy. The results indicate that the valence band and core electronic states of V O2 shift systematically to lower binding energy upon photocarrier injection, consistent with doping in a rigid-band picture. The shift in binding energy, and its saturation, follows the known photovoltage behavior. In addition, the V 3d states near EF exhibit a redistribution/transfer of spectral weight, similar to the temperature dependent insulator to metal transition in V O2. The study provides evidence for hole-doping induced electronic structure changes due to the photocarriers in V O2.