Nonvolatile memory elements based on organic materials

Many organic electronic devices exhibit switching behavior, and have therefore been proposed as the basis for a nonvolatile memory (NVM) technology. This Review summarizes the materials that have been used in switching devices, and describes the variety of device behavior observed in their charge-voltage (capacitive) or current-voltage (resistive) response. A critical summary of the proposed charge-transport mechanisms for resistive switching is given, focusing particularly on the role of filamentary conduction and of deliberately introduced or accidental nanoparticles. The reported device parameters (on-off ratio, on-state current, switching time, retention time, cycling endurance, and rectification) are compared with those that would be necessary for a viable memory technology. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA.