Furan-Containing Quinoidal Compounds for High-Performance Copper/Silver Electrode-Based n‑Channel Organic Transistors

Furan-containing quinoidal compounds FTzTzF-C10 and FTzTzF-C8
were
synthesized. These compounds have low lowest unoccupied molecular
orbital (LUMO) energy levels and can form a charge transfer complex
with Ag and Cu films, proved by cyclic voltammograms and Raman spectra.
Single crystal diffraction results reveal that they adopt a lamellar
layer structure with strong π–π interactions in
crystals. Thin film transistor characterization shows that FTzTzF-C10
and FTzTzF-C8 exhibit n-channel behavior with an electron mobility
of 1.18 cm2 V–1 s–1, one of the highest electron mobilities reported for thin film devices
based on furan-containing semiconductors. Notably, the performance
of FTzTzF-C10 and FTzTzF-C8 devices is nearly independent of the metals
(Au, Cu, and Ag) of source–drain electrodes, which is ascribed
to the ultrathin charge transfer layer formed by the spontaneous reaction
of FTzTzFs and electrodes (Ag, Cu). These results demonstrate that
furan is an excellent block for quinoidal semiconductors and promote
the development of Cu/Ag electrode-based organic transistors.