n-channel organic thin film transistors and complementary inverters

Abstract

n-channel organic thin film transistors (OTFTs) with field-effect mobility comparable to that typically reported for p-channel pentacene TFTs were fabricated on oxidized silicon wafers using N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C₁₃H₂₇) as the semiconductor. Au, Cr, Al, and LiF/Al source and drain contacts were studied. Accumulation mode n-channel transistor operation was demonstrated for all contact metals despite the large differences in their work functions. High field effect mobility near 0.6 cm²/Vs and large I_on/I_off of 10⁷ were achieved for the best device which compares favorably with the best reported performance for OTFTs fabricated using this class of material. Despite the impressive performance significant device instability was observed. n-channel TFT performance was sufficient to demonstrate pentacene/PTCDI-C₁₃H₂₇ TFT complementary inverters with a high gain of 140.