Synthesis and characterization of a fluorinated oligosiloxane-containing encapsulation material for organic field-effect transistors, prepared via a non-hydrolytic sol-gel process

Abstract

The operation of stable organic field-effect transistors (FETs) over long periods of time requires that organic FETs are encapsulated. We synthesized an inorganic-organic hybrid non-hydrolytic sol-gel material (TPDt) containing fluoroalkyl functional groups to encapsulate organic FETs. Fourier-transform infrared spectroscopy, atomic force microscopy, UV-Visible spectroscopy, and water contact angle measurements demonstrated that the TPDt films displayed smooth surfaces, good hydrophobicity, and optical transparency. The gas barrier properties of the TPDt films were tested by fabricating FETs using an organic semiconductor, poly[9,9-dioctylfluorenyl-2,7-diyl]-co-(bithiophene)]. The organic FETs were operated at 38 degrees C in the presence of a 90% relative humidity air atmosphere. The field-effect mobility of the organic FET decreased only negligibly, even after 2500 h operation under these conditions.