It has been found that bismuth ferrite (BiFeO 3 , BFO) is not only a promising multiferroic material but also shows optical response in visible wavelength. This enables BFO a probable application in optoelectronic device with visible light source. However, the high leakage current in BFO greatly impedes its practical application. BiFeO 3 -PbTiO 3 (BFO-PT), the derivative of BFO, has been proved exhibiting improved insulation. We have reported that the band gap of 0.7BFO-0.3PT thin film also locates in the visible green light. Nevertheless, the dependence of optical properties on composition in BFO-PT thin films is few documented. In this work, the electrical properties and optical response of xBFO-(1-x)PT (0.1 ≤ x ≤ 0.9) thin films are carefully examined and the band gap of the films are analyzed. The effect of composition on phase structure, electrical and optical properties in BFO-PT films will be investigated.
Keywords-BiFeO 3 -PbTiO 3 , thin film, optical band gapI.