Fabrication and Characterization of Poly(3-hexylthiophene)-Based Field-Effect Transistors with Silsesquioxane Gate Insulators

Abstract

The preparation of organic–inorganic hybrid gate dielectrics of poly(methyl silsesquioxane) (PMSQ) at a low processing temperature has been studied for use in organic field-effect transistors (OFETs) by the solution process. It is found that the electrical resistivity of a PMSQ film synthesized by a sol–gel method is significantly influenced by the synthesis conditions such as the type of organic solvent used and water content. PMSQ films prepared in toluene show a high resistivity of over 1014 Ω cm even at a low thermal treatment of 150 °C, which is attributed to the decrease in the silanol concentration of the PMSQ films. Top-contact OFET fabricated on a PMSQ-coated SiO2 gate dielectric using poly(3-hexylthiophene) exhibits mobility improvement similarly to devices with self-assembled monolayer-modified SiO2 dielectrics.