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 $-3.0\mathrm{V}$ , high saturation mobilities of $\sim 3.5{\mathrm{cm}}^2∕\mathrm{V}\mathrm{s}$ , and on-off current ratio of ${10}^5$ . 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 $24\mathrm{mm}$ , 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.