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MM: Fachverband Metall- und Materialphysik
MM 33: Transport II - charge transport
MM 33.2: Talk
Tuesday, March 21, 2017, 12:15–12:30, IFW D
Temperature dependence and lateral distribution of bias voltage driven charge transport through thin tantalum oxide films — •Jan Philipp Meyburg1, Detlef Diesing1, and Achim Walter Hassel2 — 1Institut für Physikalische Chemie, Universität Duisburg-Essen — 2Johannes Kepler Universität Linz, 4040 Linz, Austria
The temperature dependence and the lateral distribution of currents in tantalum oxide (3–4 nm) based metal–insulator–metal devices induced by an applied voltage bias is studied from 80 K to 500 K. The sensitivity of the devices to a temperature change strongly depends on the polarity of the applied bias voltage. When the bias voltage weakens the internal field, the current increases by 4 orders of magnitude (Temperature increased from 400 K to 500 K). With bias voltages strengthening the internal field the current increases only by several 10 %. This asymmetry of the temperature dependence is strongly correlated with the asymmetry of the tunnel barrier and cannot be understood within the established Poole–Frenkel conduction or Schottky emission models. A new model presented here which fully includes the carrier transmission through a tilted barrier shows that tunnel emission explains the temperature dependences at different bias voltages.