Process optimization of organic thin-film transistor by ink-jet printing of DH4T on plastic

Abstract

The authors studied the organic thin-film transistor (OTFT) with a solution based dihexylquaterthiophene (DH4T) by ink-jet printing. The DH4T with 1.0wt% solution in dichlorobenzene was used for printing of an active layer of OTFTs. In order to obtain a smooth and uniform film of DH4T, the substrate temperature was elevated to 60°C and the printing was performed by an overlapping method. The OTFT on plastic exhibited an on/off current ratio of ∼107, a threshold voltage of −0.25V, a gate voltage swing of 0.45V/decade, and a field-effect mobility of 0.043cm2∕Vs in the saturation region.