Resistance state-dependent barrier inhomogeneity and transport mechanisms in resistive-switching Pt/SrTiO3 junctions

We investigated the current-voltage (I-V) and photocurrent characteristics of Pt/Nb-doped SrTiO3 (001) single-crystal junctions that exhibit resistive-switching behaviors. The temperature-dependent I-V data and the photocurrent spectra showed that the barrier height fluctuation depended on the resistance state but the mean barrier height was nearly constant regardless of the junctions' resistance state. In addition, local barrier height variations allowed transitions from thermionic to tunneling transport for the low-resistance state. (C) 2011 American Institute of Physics. [doi:10.1063/1.3567755]