Resistance Switching in Organic Electronic Devices: Mechanism and Applications
Sebastian Nau
NanoTecCenter Weiz Forschungsgesellschaft mbH
14:00 - 14:20 Thursday 23 October 2014 Rechbauerstrasse 12, HSII Electrically tunable resistors (memristors) realized in two terminal structures seem to be one of the most versatile innovations in the semiconductor industry with many possible applications not only as non-volatile memory, but also in the field of logic circuitry or neuromorphic systems. Resistance switching was observed from a manifold of organic electronic devices, however despite vital academic interest a consistent explanation about their working mechanisms is missing. Different models are proposed in this relation, most commonly charging/discharging of metallic particles in an organic matrix and the related formation of a space charge field capable of influencing current injection or the formation of highly conductive and localized pathways.
We herein present a set of experiments (I/V characterization, photovoltaic measurements and impedance spectroscopy) to shed light on unipolar resistance switching in organic devices: For the first time, all charging based models which were held to be responsible for the switching can unambiguously ruled out. We show that the switching behavior can be interpreted as the formation and rupture of a conductive pathway (‘filament’). Therefore unipolar resistance switching can be considered as a fundamental property of electrode/organic/electrode systems, making this finding significant for researchers working on other typical organic thin film ‘sandwich’ devices like organic photovoltaic devices or organic light emitting diodes, where the formation of parasitic current pathways through the device is doubtless an undesired side-effect.[1]
Based on the advanced understanding of the working mechanism, we present unique and novel applications of organic resistive switching devices like organic image detector arrays and organic x-ray detectors. Further, alternative fabrication strategies as inkjet-printing or metal transfer lamination will be discussed. (Fig. 1)
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