Inkjetted crystalline single monolayer oligothiophene OTFTs

Crystalline monolayer films of a novel organic semiconducting material were deposited as the active layer for organic thin-film transistors (OTFTs) via inkjet printing. Devices exhibited field-effect mobilities up to 0.07 cm/sup 2//V/spl middot/s and on/off ratios >10/sup 8/, surpassing values measured for devices cast with thicker films of the same material. The printed monolayer devices exhibited superior subthreshold characteristics with less hysteresis, and defect and trap densities are improved over thicker film analogs. These results show that solution deposition techniques such as inkjet printing can result in the monolayer crystalline thin films that are requisite for near-ideal electrostatics in OTFTs.