Solution-processed organic thin-film transistors with vertical nanophase separation

We have found that spin coating a solution of 6,13-bis(triisopropyl-silylethynyl)-pentacene (TIPS-pentacene) blended with poly(alpha-methylstyrene) (P alpha MS) induces vertical nanophase separation, which results in a trilayer film: a TIPS-pentacene layer, a mixed layer of TIPS-pentacene/P alpha MS, and a TIPS-pentacene layer. Organic thin-film transistors (TFTs) made from this TIPS-pentacene/P alpha MS solution have remarkably improved uniformity and thermal stability without degradation of electrical characteristics compared to organic TFTs with a conventional TIPS-pentacene sole channel layer. (C) 2008 American Institute of Physics.