Print Email Facebook Twitter Retention time and depolarization in organic nonvolatile memories based on ferroelectric semiconductor phase-separated blends Title Retention time and depolarization in organic nonvolatile memories based on ferroelectric semiconductor phase-separated blends Author Asadi, K. Wildeman, J. Blom, P.W.M. de Leeuw, D.M. TNO Industrie en Techniek Publication year 2010 Abstract Resistive switches have been fabricated using a phase-separated blend film of ferroelectric random copolymer poly(vinylidene fluoride-co-trifluoroethylene) with the organic semiconductor regio-irregular poly(3-hexylthiophene) (rir-P3HT). Spin-coated blend films have been contacted with symmetrical Ag top and Ag bottom electrodes, yielding switching diodes. The ferroelectric polarization modulates the injection barrier, yielding an injection-limited off-state and a space-charge-limited on -state. To study the effect of depolarization, an additional polyphenylenevinylene-type semiconductor layer with the highest occupied molecular orbital energy that is comparable to that of rir-P3HT has been inserted in the diode stack. When the ad-layer is the injecting contact, the current modulation ratio goes to unity. The origin is a decrease in the effective band bending at the contact with increasing ad-layer thickness. When the counter electrode at the blend interface is the injecting contact, the diode can be switched, but the on-state is only stable when an electric field that is larger than the coercive field is applied. Upon field removal, the ferroelectric depolarizes, and the current drops to that of an unpoled pristine diode. The depolarization is confirmed by capacitancevoltage and retention time measurements. To realize bistable diodes with excellent retention times, the thickness of the semiconducting wetting layer may not be at most 10 nm. © 2006 IEEE. Subject Mechatronics, Mechanics & MaterialsHOL - HolstTS - Technical SciencesHigh Tech Systems & MaterialsElectronicsIndustrial InnovationDepolarizationBandbendingBistablesBlend filmsBottom electrodesCapacitance voltageCoercive fieldCounter electrodesCurrent modulationDiode stacksFerroelectric polarizationFerroelectric semiconductorsHighest occupied molecular orbitalInjection barriersLayer thicknessNon-volatile memoriesOrganic nonvolatile memoriesOrganic semiconductorPoly (3-hexylthiophene)Random copolymerRetention timeSemiconductor layersSpace-charge-limitedSwitching diodesTrifluoroethyleneVinylidene fluorideWetting layerDepolarizationElectric fieldsFerroelectricityMolecular orbitalsOrganic polymersSwitching systemsTime measurementSemiconductor diodes To reference this document use: http://resolver.tudelft.nl/uuid:c1300edb-2fc3-4e9f-b9f6-fda89933ac57 TNO identifier 461515 ISSN 0018-9383 Source IEEE Transactions on Electron Devices, 57 (12), 3466-3471 Article number No.: 5582274 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.