Solution-processed trilayer inorganic dielectric for high performance flexible organic field effect transistors

High performance organic field effect transistors using a solution-processable processed trilayer sol-gel silica gate dielectric architecture fabricated on plastic substrates exhibited low driving voltages of -3.0 V, high saturation mobilities of ∼3.5 cm2 V s, and on-off current ratio of 105. The enhancement in field effect mobility is attributed to improved dielectric-semiconductor interfacial morphology and increased capacitance of the tristratal dielectric. The pentacene devices displayed no signs of electrical degradation upon bending through a bending radius of 24 mm, 2.27% strain. The slight increase in the drain currents upon bending strain was investigated using Raman spectroscopy, which revealed enhanced in-phase intermolecular coupling.