Photovoltaic effects in Bi4Ti3O12 thin film prepared by a sol-gel method

Bi4Ti3O12 (BTO) film has been successfully fabricated on fluorine-doped tin oxide conductive glass substrate by the sol-gel technique. The optical band gap of 3.37 eV can be estimated from the UV-vis absorption spectrum. Piezoelectric force microscopy measurement confirms the local ferroelecitity of the BTO film. Seen from the J-V curve, the short circuit photocurrent density is about -75 nA/cm(2) and the open circuit voltage is about 0.13 V under the incident light intensity of 100 mW/cm(2). The time dependence of the zero bias photocurrent density with light ON/OFF demonstrates stable and repeatable instantaneous photocurrent. It is suggested that the interfacial Schottky barriers are responsible for the separation of electron-hole pairs in the BTO film. (C) 2014 Elsevier B.V. All rights reserved.