Surface states at semiconductor-liquid junction

Abstract
Surface states at a junction of n-TiO2 and aqueous solution were studied by means of the capacitance measurement. It appeared that, from the relation between surface-state capacitance and electrode potential, surface states with state density of 8×1012 cm−2 were located at 0.5 eV below the bottom of the conduction band. The electron capture cross section of 2.0×10−19 cm2 was obtained from the frequency dependence of surface-state capacitance. The effect of the UV irradiation of TiO2 on the surface-state capacitance suggested that this surface state originated from adsorbates.