Ladder-Like Polysilsesquioxane Dielectrics for Organic Field-Effect Transistor Applications

초록

A series of trimethylsilyl-capped hybrid ladder-like polysilsesquioxane (LPSQ-TMS) derivatives were synthesized comprising of an inorganic backbone functionalized with various organic side moieties and compositional ratios with application for gate dielectrics or surface modifiers. The surface energy and roughness values of LPSQ-TMS coated SiO2 dielectrics were considerably affected by the side moieties. On smooth and semiconductor-compatible polymer-treated surfaces, pentacene developed terrace-like crystallites, a stark contrast to the three-dimensionally grown crystal islands formed on rough or extremely hydrophobic surfaces. For two kinds of surfaces, the average mobility values of the pentacene OFETs were varied by two orders of magnitude and reached 0.8 cm2 V-1 s-1. Moreover, a thermally cured 500 nm thick LPSQ-TMS layer on patterned flexible polyimide substrate could yield pentacene OFETs with mobility of 0.60 cm2 V-1 s-1, comparable to that of the LPSQ-TMS treated SiO2 system.