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.
Bibliographical noteFunding Information:
This work was supported by the Quantum Metamaterials Research Center (Grant No. 2009-0063324) and the Pioneer Research Center Program (Grant No. 2010-0002231) through the National Research Foundation of Korea Grant funded by the Ministry of Education, Science, and Technology, and the National Program for 0.1 Terabit NVM Devices sponsored by the Korean Ministry of Knowledge and Economy.