Bi4Ti3O12/BiFeO3 (BTO/BFO) heterostructurebilayer film ispreparedon fluorine-doped tinoxide
conductiveglassbyasol–gel process.TheX-raydiffractionresultshowsthatnoadditionalphasecan
be foundbesidesthecharacteristicdiffractionpeaksofBTOandBFO.Piezoelectricforcemicroscopy
measurement confirms thecompletedomainswitchingandlocalferroelectricnature.Theopencircuit
voltageandshortcircuitcurrentdensityofthebilayer film aremeasuredtobeabout0.38Vand
56.24 mA cm2, respectively,higherthanthoseoftheBTO.TheBTO/BFO film exhibitsrepeatableand
stable instantaneousresponseofphotocurrent.Atheoreticalbanddiagrammodelcombining p–n
heterostructurewithferroelectricpolarizationisconstructedtodescribethemechanismofphotovoltaic
enhancement ofthe film.