Electrode-dependent electrical properties of metal/Nb-doped SrTiO3 junctions

In this study, we discuss the electrical properties of junctions consisting of metal electrodes and Nb-doped SrTiO3(001) single crystals. The junctions formed with large work function metals (Ni, Au, Pd, and Pt) resulted in rectifying transport. A hysteretic feature was observed in the current (I)-voltage (V) and capacitance (C)-V characteristics of these junctions upon polarity reversal. The ideal Schottky-Mott rule could not explain the barrier height obtained from the I-V data, indicating the existence of interface states. Analyses of the C-V data revealed that a low dielectric constant layer existed at the interface. The interface states and layers affected the transport and the related resistance switching characteristics of the junctions. (c) 2008 American Institute of Physics.