Substantial reduction of leakage currents in La/Er/Zn/Ti multielement-doped BiFeO₃ multiferroic thin films

Multi-element doping is an effective method to suppress the leakage of BiFeO3 (BFO). A systematic study on the effect of various elements (La, Er, Zn, Ti) doping on the leakage performance, mechanism and other electrical properties of BFO films was performed As the kinds of doping elements increases, the leakage current density of the BFO film gradually decreases. The leakage current density is gradually reduced from 5.78 x 10(-2) A/cm(2) doped with one element (La) to 1.25 x 10(-2) A/cm(2) doped with two elements (La, Ti), 4.13 x 10(-3) A/cm(2) doped with three elements (La, Ti, Zn), and 4.53 x 10(-4) A/cm(2) doped with four elements (La, Er, Zn, Ti). Finally, compared with pure BFO films, the leakage current density in doped BFO films is reduced by two orders of magnitude. Moreover, the conduction mechanism in doped BFO films is gradually changed from space charge limited current to ohmic conduction. This work provides an effective method to ameliorate the leakage of ferroelectric materials and lays a foundation for the practical application of BFO-based films.