Enhanced ferroelectric and photoelectric properties in lead-free Bi1.07FeO3-modified K0.5Na0.5NbO3 thin films

Lead-free (K0.5Na0.5NbO3)0.97–(Bi1.07FeO3)0.03 (KNN–BFO) ferroelectric thin films were epitaxially grown on LaNiO3-buffered SrTiO3(STO) by the pulsed laser deposition. The influence of the BiFeO3 addition on the electrical, bandgap, and photoelectric properties in KNN thin films was investigated systematically. Interestingly, compared with KNN films, the KNN–BFO thin films exhibit a significant enhancement on the ferroelectric and photoelectric properties. The enhanced ferroelectric properties were due to the depression of the leakage current and the improvement of the ferroelectric domains. Moreover, the photoelectric effect in the visible region can be ascribed to the improved ferroelectric properties and the narrow bandgap of KNN film modified by BiFeO3 addition. Our results indicate that the lead-free KNN–BFO thin films with enhanced ferroelectric and photoelectric characterizers may own a potential for environmental-friendly informational storage and photoelectric devices.