Thiol-ene polymer based fast photo-curable gate insulator for organic field effect transistors

We report the synthesis and properties of fast photo-cured polymer dielectrics used as top gate insulators in organic field-effect transistors (OFETs). Two thiol functionalized compounds and a vinyl ether monomer were used to formulate thiol-ene polymers. The kinetic of the photo-curing of these formulations was determined by monitoring the curing process by FT-IR spectroscopy. Guided by measurements on metal-insulator-metal and metal-insulator-semiconductor structures, we determined the composition of the thiol-ene polymer and the optimal time of exposure to UV-irradiation to fabricate high performance poly(3-hexylthiophene)-based OFETs. We cured a mixture of a mercapto-functionalized polysiloxane produced with sol-gel process, 1,4-cyclohexanedimethanol divinyl ether and irgacure 127 in 15 s. The produced transistors have high on/off ratios of 10(5). The OFETs showed a field effect mobility of 10(-2) cm(2) V-1 s(-1) and low threshold voltage of -3 V. (C) 2013 Elsevier B.V. All rights reserved.