All ink-jet printed low-voltage organic field-effect transistors on flexible substrate

In this work, all ink-jet printed (IJP) low-voltage organic field-effect transistors (OFETs) on flexible substrate are reported. The OFETs use IJP silver (Ag) for source/drain/gate electrodes, poly(4-vinylphenol) (PVP) for gate dielectric, 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) blended with polystyrene (PS) as the semiconducting layer and CYTOP for encapsulation layer. All the printing processes were carried out in ambient air environment using a single laboratory ink-jet printer Dimatix DMP-2831. The all IJP device presents state-of-the-art performance with low operation voltage down to 3 V, small subthreshold swing (SS) of 0.155 V/decade, mobility of 0.26 cm2 V−1s−1, threshold voltage (Vth) of −0.17 V and on/off ratio of 3.1 × 105, along with a yield of 62.5%. Through interface engineering and proper process optimization, this work demonstrates a promising low-voltage all IJP device platform for low-cost flexible printed electronics.