Functionalized p-dopants as self-assembled monolayers for enhanced charge carrier injection in organic electronic devices

We demonstrate that electrical dopants can be modified with self-assembling groups to form injection layers in organic electronic devices. A strong p-type dopant has been modified in a one-step synthesis to form self-assembled monolayers on gold electrodes from solution. F(4)TCNQ was functionalized with sulfur-containing triazole anchor groups via nucleophilic substitution in a simple substitution reaction. Assembly of functionalized dopants on gold surfaces was verified by ATR-FT-IR measurements. Pentacene-based bottom gate, bottom contact organic thin film transistors show a strongly improved performance. The effective mobility could be increased by a factor of three when electrodes were covered with a SAM of functionalized dopant. (C) 2013 Elsevier B. V. All rights reserved.