Organic Crystal Gate Insulators for High-mobility Organic Single-crystal Transistors

摘要

High-mobility organic transistors are fabricated on both surfaces of approximately 1-μm thick rubrene crystals with molecularly flat region over the area of 10 × 10 μm~2. A thin platelet of 9,10-diphenylanthracene (DPA) single crystals with equally flat surfaces and a surface-passivated SiO_2 are used for the gate insulators. Because of minimized densities of hole-trapping levels at the interfaces and in the rubrene crystal, the carrier mobility of more than 20 cm~2/Vs is realized for the independent operation of the double-gate OFETs. Moreover, Best-tuning the two gate voltages with the opposite signs, even higher mobility of 43 cm~2/Vs has been realized for the double-gate rubrene transistor, as the result of mutual exchange of the carriers between the top and the bottom surfaces of the thin rubrene crystals.