The vast majority of conjugated-polymer-based light emitting field-effect transistors (LEFETs) are characterized by low charge-carrier mobilities typically in the 10−5 to 10−3 cm2 V−1 s−1 range. Fast carrier transport is a highly desirable characteristic for high-frequency LEFET operation and, potentially, for use in electrically pumped lasers. Unfortunately, high-mobility organic semiconductors are often characterized by strong intermolecular π–π interactions that reduce luminescence. Development of new materials and/or device concepts that overcome this hurdle are therefore required. Single organic semiconductor layer based LEFETs that combine high hole mobilities with encouraging light emission characteristics are reported. This is achieved in a single polymer layer LEFET, which is further enhanced through the use of a small-molecule/conjugated polymer blend system that possesses a film microstructure which supports enhanced charge-carrier mobility (3.2 cm2 V−1 s−1) and promising light-emission characteristics (1600 cd m−2) as compared to polymer-only based LEFETs. This simple approach represents an attractive strategy to further advance the performance of solution-processed LEFETs.
KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This work was supported by a Durham Junior Research Fellowship COFUNDed by Durham University and the European Union (Grant Agreement no. 609412). J.P. and T.D.A. acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC Grant number EP/G037515/1) and from the European Research Council (ERC) AMPRO project no. 280221. D.D.C.B. thanks the University of Oxford for start-up funding, including a postdoctoral research fellowship for S.N. The authors also thank Merck Chemicals Ltd for providing the polymer for this study and Nathan Cheetham for assistance with PLQE analysis. A.S. and J. L. thank Nathan Cheetham for his support with PLQE analysis Henry Snaith for the access to the facilities. T.D.A. acknowledges King Abdullah University of Science and Technology (KAUST) for financial support. Authors also acknowledge Christina Kaiser and Ardalan Armin (Swansea University) for their help in calculation of outcoupling efficiency for anisotropic indices.