Influence of gate dielectrics on the performance of single-layered organic transistors and bi-layered organic light-emitting transistors prepared by the neutral cluster beam deposition method

The influence of two different SiO(2) and polymethylmethacrylate (PMMA) gate dielectrics on the performance of single-layered organic field-effect transistors and bi-layered organic light-emitting field-effect transistors was examined. Organic active layers of p-type alpha,omega-dihexylsexithiophene and n-type N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide were prepared using the neutral cluster beam deposition method. Characterization of surface morphology, contact angles, structural properties and temperature dependence of field-effect mobilities measured over the temperature range of 10-300 K revealed that compared to the SiO(2) dielectrics, the hydroxyl-free PMMA dielectrics provided better conditions for crystalline film growth. The PMMA-based device characteristics exhibited excellent field-effect mobilities, stress-free operational stability, and electroluminescence through efficient carrier transport and well-balanced ambipolarity under ambient conditions. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3573537]