title: Electrical in-situ characterisation of interface stabilised organic thin-film transistors.
abstract: We report on the electrical in-situ characterisation of organic thin film transistors under high vacuum conditions. Model devices in a bottom-gate/bottom-contact (coplanar) configuration are electrically characterised in-situ, monolayer by monolayer (ML), while the organic semiconductor (OSC) is evaporated by organic molecular beam epitaxy (OMBE). Thermal SiO2with an optional polymer interface stabilisation layer serves as the gate dielectric and pentacene is chosen as the organic semiconductor. The evolution of transistor parameters is studied on a bi-layer dielectric of a 150 nm of SiO2and 20 nm of poly((±)endo,exo-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, diphenylester) (PNDPE) and compared to the behaviour on a pure SiO2dielectric. The thin layer of PNDPE, which is an intrinsically photo-patternable organic dielectric, shows an excellent stabilisation performance, significantly reducing the calculated interface trap density at the OSC/dielectric interface up to two orders of magnitude, and thus remarkably improving the transistor performance.
authors.affiliation: Joanneum Research Forschungsgesellschaft mbH, MATERIALS-Institute for Surface Technologies and Photonics, Franz-Pichler Straße 30, 8160 Weiz, Austria.
authors.forename: Bernd
authors.initials: B
authors.lastname: Striedinger
authors.affiliation: Joanneum Research Forschungsgesellschaft mbH, MATERIALS-Institute for Surface Technologies and Photonics, Franz-Pichler Straße 30, 8160 Weiz, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Fian
authors.affiliation: Joanneum Research Forschungsgesellschaft mbH, MATERIALS-Institute for Surface Technologies and Photonics, Franz-Pichler Straße 30, 8160 Weiz, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Petritz
authors.affiliation: Graz University of Technology, Institute of Solid State Physics, Petersgasse 16, 8010 Graz, Austria.
authors.forename: Roman
authors.initials: R
authors.lastname: Lassnig
authors.affiliation: Graz University of Technology, Institute of Solid State Physics, Petersgasse 16, 8010 Graz, Austria.
authors.forename: Adolf
authors.initials: A
authors.lastname: Winkler
authors.affiliation: Joanneum Research Forschungsgesellschaft mbH, MATERIALS-Institute for Surface Technologies and Photonics, Franz-Pichler Straße 30, 8160 Weiz, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Stadlober
keywords: in-situ characterisation; norbornene; organic thin-film transistors; pentacene; polymer dielectric