Solution processed OTFT circuits on plastic substrates

Solution-processed organic thin film transistors (OTFTs) may allow high volume, low cost manufacturing approaches such as ink-jet printing and roll-to-roll processing. Poly (3-hexylthiophene) (P3HT) based solution-processed 5-stage ring oscillators with frequency of several kHz and 7-stage ring oscillators using soluble rubrene with frequency of 1.5 kHz (for V_dd=-45 V) have been reported. We report here 7-stage and 15-stage ring oscillators using spin cast fluorinated 5,11-Bis(triethylsilylethynyl) anthradithiophene (F-TES ADT) on plastic substrates with maximum oscillation frequency of more than 22 kHz and minimum propagation delay less than 3.3 mus/stage (for 7-stage ring oscillators for V_dd=-80 V). These circuits also oscillate with supply voltage as low as -3 V and have stable operation at V_dd=-5 V with oscillation frequency of ~2.8 kHz.