Berlin 2008 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 11: Dielectric and ferroelectric thin films and nanostructures I

DF 11.6: Talk

Wednesday, February 27, 2008, 15:40–16:00, EB 107

Field effect transistor of graphitized polyimide with P(VDF-TrFE) as gate insulator — •I. Lazareva¹, Y. Koval¹, P. Müller¹, I. Paloumpa², K. Müller², and D. Schmeisser² — ¹Institut für Physik der Kondensierten Materie, Universität Erlangen-Nürnberg, Erwin-Rommel Str. 1, 91058 Erlangen, Germany — ²Lehrstuhl Angewandte Physik/Sensorik, Brandenburgische Technische Universität Cottbus, Konrad-Wachsmann-Allee 1, 03046 Cottbus, Germany

Surfaces of polyimide films were graphitized by low-energy ion irradiation. The conductivity was between 10⁻⁵ to 200 S/cm [1]. We prepared field effect transistors using this material. Ferroelectric P(VDF-TrFE) was used as gate insulator. The thickness of P(VDF-TrFE) varied from 120 nm to 1200 nm. Properties of P(VDF-TrFE) were investigated by current-voltage measurements of metal/ P(VDF-TrFE)/metal capacitors. We have found that at room temperature, the coercive field of P(VDF-TrFE) does not depend on the film thickness. At lower temperatures the coercive field increases proportionally to the reciprocal temperature. Remnant polarization is  9.5 µC/cm². It slightly rises with decreasing temperature. Our recent results of field effect mobility, carrier concentration and threshold voltage are presented.

[1] I. Lazareva, Y. Koval, M. Alam, S. Strömsdörfer, P. Müller, Appl. Phys. Lett. 90, 262108 (2007)