Fast organic circuits on flexible polymeric substrates

We have fabricated the fastest organic circuits on flexible substrates yet reported. These circuits use the small-molecule hydrocarbon pentacene as the active semiconductor material and 75 /spl mu/m thick flexible, transparent, colorless, polyethylene naphthalate (PEN) film as the substrate. Transistor arrays, inverters, ring oscillators, and other circuits with good electrical performance, yield, and uniformity were obtained. A field-effect mobility of 1 cm/sup 2// V-s was extracted from OTFT saturation characteristics, and ring oscillators had minimum propagation delay <40 /spl mu/sec per stage and <50 /spl mu/sec per stage at bias levels below 8 V.