Current-voltage behaviors of BiFeO3/poly(vinylidene fluoride-trifluoroethylene) composite films

Highlights: • BiFeO₃/P(VDF-TrFE) composite films of different mass ratios were fabricated. • Polycrystalline phases of BiFeO₃ and P(VDF-TrFE) were confirmed separately. • Space charge limited conduction mechanism contributed to its leakage behaviors. -- Abstract: BiFeO₃ (BFO) nanopowders (NPs) were synthesized using sol-gel method. BFO/P(VDF-TrFE) (poly(vinylidene fluoride-trifluoroethylene)) composite films were then fabricated on fluorine-doped tin oxide conductive glass substrates by solution spin-coating method. Polycrystalline phases of BFO and P(VDF-TrFE) were identified by X-ray diffraction. Field emission scanning electron microscopy showed that BFO NPs were uniformly dispersed in the P(VDF-TrFE) matrix. The conduction mechanism of BFO/P(VDF-TrFE) composite films was analyzed on account of various conduction mechanisms by analyzing the current-voltage (I-V) curves. As a result, the space charge limited conduction mechanism should be reasonable for the special I-V characteristics of the composite films. Furthermore, the space charge region of the curve mainly came from traps/defects that may be originated from imperfect crystallization of the copolymer matrix and high conductivity BFO NPs as well.