The electrical conduction mechanism within a resistive switching TiO 2 film in its bipolar high resistance state was examined by ac impedance spectroscopy and dc current-voltage measurements. Bipolar switching, which can be initiated from a unipolar high resistance state, was attributed to both modulation of the Schottky barrier height at the film-electrode interface and the electronic energy state in the film. Numerical fittings of the impedance data revealed two distinct RC domains in series, which were attributed to an interfacial barrier (activation energy ∼0.1 eV) and a nonconducting layer (activation energy ∼0.5 eV), respectively.
Bibliographical noteFunding Information:
The authors acknowledge the support of the National Research Program for the Nano Semiconductor Apparatus Development and 0.1 Terabit NVM Devices sponsored by the Korean Ministry of Knowledge and Economy, and World Class University program through the Korea Science and Engineering Foundation funded by the Ministry of Education, Science and Technology (Grant No. R31-2008-000-10075-0).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)