Herein is presented systematic analysis of air-stable, ambipolar heterojunction-based organic light-emitting field-effect transistors (OLEFETs). Top-contact OLEFETs with multidigitated, long channel-width geometry were produced by the successive deposition of electron-transporting N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13) and hole-transporting tetracene layers, using the neutral cluster beam deposition (NCBD) method. The morphological, structural, and photoluminescence properties of the untreated and thermally post-treated P13/tetracene active layers were examined by atomic force microscopy, X-ray diffraction, and laser scanning confocal microscopy. From the comparative analysis of the NCBD thin films, the neutral cluster beams led to the preparation of smooth, uniform bilayer films consisting of well-packed grain crystallites. The OLEFETs demonstrated good field-effect characteristics, stress-free operational stability, and electroluminescence under ambient conditions. The operating conduction mechanism that accounts for the observed light emission is also discussed.

No abstract

In this paper, we report on the fabrication and electrical characterization of top-contact, ambipolar organic field-effect transistors (OFETs) and inverters based upon a heterostructure of p-type pentacene on n-type N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic di-imide (P13), using the neutral cluster beam deposition (NCBD) method. The device characteristics measured as a function of both P13 and pentacene layer thicknesses revealed that OFETs with thicknesses of P13 (300 Å) and pentacene (200 Å) showed high air-stability and well-balanced ambipolarity with hole and electron mobilities of 0.12 and 0.08 cm2/V s. The complementary inverters, comprising two identical ambipolar OFETs, were found to operate both in the first and third quadrants of the transfer curves and exhibited a high voltage inversion gain of 13, good noise margins, and little hysteresis under ambient conditions. The results presented demonstrate that the NCBD-based ambipolar transistors and inverters qualify them as promising potential candidates for the construction of high-performance, organic thin film-based integrated circuits.

The influence of two different SiO2 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 α,ω-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 SiO2 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.

No abstract