Additive effect of poly(4-vinylphenol) gate dielectric in organic thin film transistor at low temperature process.

We fabricated pentacene-based organic thin film transistors (OTFTs) with formulated poly[4-vinylphenol] (PVP) gate dielectrics. The solution of gate dielectrics is prepared by adding methylated poly[melamine-co-formaldehyde] (MM F) and photo-initiator (PI) [1-phenyl-2-hydroxy-2-methylpropane-1-one, Darocur1173@Ciba] to PVP. By using a small amount (2.4 wt%) of PI, the cross-linking temperature is lowered to 90 degrees C, which is lower than general thermal curing reaction temperature for the cross-linked PVP (>180 degrees C). The hysteresis and the leakage current of the OTFTs are also decreased by adding the MMF and PI in the PVP gate dielectric.