All jet-printed polymer thin-film transistor active-matrix backplanes

Thin-film transistor (TFT) backplanes fabricated by using jet printing as the only patterning method are reported. Additive and subtractive printing processes are combined to make 128 × 128 pixel active matrix arrays with 340 μ m pixel size. The semiconductor used, a regioregular polythiophene, poly [ 5 , 5 ′ - bis ( 3 - dodecyl - 2 - thienyl ) - 2 , 2 ′ - bithiophene ] ; (PQT-12) is deposited by inkjet printing and exhibits average TFT mobility of 0.06 cm 2 ∕ Vs , on/off ratios of 10 6 , and minimal bias stress. The printed TFTs have high yield with a narrow performance distribution. The pixel design benefits from the registration accuracy of jet printing and it is shown that the electrical performance is suitable for addressing capacitive media displays.