Ultrasmall magnetic field-effect and sign reversal in transistors based on donor/acceptor systems.

ABSTRACT: We present magnetoresistive organic field-effect transistors featuring ultrasmall magnetic field-effects as well as a sign reversal. The employed material systems are coevaporated thin films with different compositions consisting of the electron donor 2,2',7,7'-tetrakis-(N,N-di-p-methylphenylamino)-9,9'-spirobifluorene (Spiro-TTB) and the electron acceptor 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile (HAT-CN). Intermolecular charge transfer between Spiro-TTB and HAT-CN results in a high intrinsic charge carrier density in the coevaporated films. This enhances the probability of bipolaron formation, which is the process responsible for magnetoresistance effects in our system. Thereby even ultrasmall magnetic fields as low as 0.7 mT can influence the resistance of t

SUBMITTER: Reichert T 

PROVIDER: S-EPMC5480331 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature