Investigation of the resistance switching in Au/SrTiO3:Nb heterojunctions

The electric properties of as-prepared and annealed Au/SrTiO3:Nb heterojunctions are comparatively investigated. The former junction has hysteretic current-voltage and apparent capacitance-voltage characteristics, showing significant resistance switching effects. The latter behaves like a conventional semiconductor Schottky contact with negligible resistance switching phenomena. Based on the equivalent circuit analysis, we demonstrated that the hysteresis of the measured apparent capacitance-voltage relation of the as-prepared junction is caused by the leakage resistance. Its real junction capacitance is not hysteretic and independent on the resistance states, following the ideal Schottky model. Our results suggest that during the resistance switching, the Schottky barrier profile is kept unchanged, and the conductive filaments play a vital role. (C) 2013 AIP Publishing LLC.