All-Solution-Processed Low-Voltage Organic Thin-Film Transistor Inverter on Plastic Substrate

In this paper, all-solution-processed low-voltage organic thin-film transistor inverters on polyethylene naphthalate plastic substrate were achieved in the bottom-gate bottom-contact device configuration. In the devices, 6,13-bis(triisopropylsilylethynyl)-pentacene blended with polystyrene was used as the channel layer, and ultraviolet cross-linked polyvinyl alcohol was used as the gate dielectric layer. With optimized inkjet jetting process parameters and a proper polymer dielectric substrate surface, fine silver electrodes were formed as the source, drain, and gate electrodes. The maximum processing temperature was 150°C. The devices show promising performance with a mobility of 0.8 cm²/(V·s), a subthreshold swing of 100 mV/decade and an ON/OFF ratio of about 10⁴. The fabricated diode-load inverter has a high dc voltage gain up to 67.3 at a supply voltage of 3 V.