Investigation of charge injection characteristics in diketopyrrolopyrrole ambipolar semiconducting polymers

A semiconducting polymers with conjugated diketopyrrolopyrrole (DPP) unit was developed for high performance ambipolar organic field-effect transistors (OFETs). We report electrical characteristics of DPP OFETs in various ways which measured transistor and inverter performance with various bias conditions and self-assembled monolayers (SAMs) treatment. Ambipolar DPP conjugated polymer OFETs showed high hole and electron mobility of μh=0.57 cm2V-1s-1 and μe=0.51 cm2V-1s-1 with O2 plasma treatment and 1-decanethiol SAMs treatment, respectively with annealing at 100°C. Contact resistance effect on mobilities was investigated by measuring contact resistance during device operation through gated four-point probe (gFPP) and simultaneous contact resistance extraction model directly from current voltage characteristics.