Enhancing rectification of Nb:SrTiO3/ZnO heterojunctions by magnetic field

(100)Nb:SrTiO3/(110)ZnO heterojunction were epitaxially grown by RF magnetron sputtering. A typical rectification characteristic was observed before and after applying a magnetic field, but the rectifying effect was significantly enhanced after applying a magnetic field. From high and low frequency capacitance-voltage measurement, the interface state density is found to increase from 3.8 × 1012 to 8.2 × 1012 eV−1 cm−2 after applying a magnetic field of 0.55 T at room temperature. Furthermore, both the rectification ratio and interface state density increase after applying a magnetic field at temperatures from 90 to 300 K. The magnetic field enhanced rectifying effect can be understood by the increase of interface state density. This result is promising for magnetoelectric applications.