Abstract:

The photovoltage properties of a new type of porous TiO₂ (P-TiO₂) were investigated through surface photovoltage spectroscopy (SPS) and field induced surface photovoltage spectroscopy (FISPS). The abundant surface states, which were related to the special porous structure, extended the SPS response band of P-TiO₂ to visible light region (500 nm), and made the intensity of surface state transition equal to that of bandband transition. When an external electric field was added, the changes in the intensity of surface state transition were not so obvious compared with that of bandband transition. These results exhibit strong “localized effect”, induced by the surface states.

Key words: titanium dioxide, surface photovoltage, surface photovoltage spectroscopy (SPS), field induced surface photovoltage spectroscopy (FISPS)