Ambipolar organic thin film transistors based on a soluble pentacene derivative

We report on ambipolar thin film transistors based on solution-deposited films of a pentacene derivative, 2,3-dicyano-6,13-bis-(triisopropylsilylethynyl)pentacene (2,3-CN2-TIPS-Pn). The ambipolar charge transport observed in this material is well balanced; the values of the hole and electron mobility are both about 2 x 10(-3) cm(2)/Vs. The position of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of 2,3-CN2-TIPS-Pn with respect to the work function of the Au charge-injecting electrode and the arrangement of the molecules in the film, as deduced by grazing incidence x-ray diffraction analysis, contributes to explain the charge transport properties of 2,3-CN2-TIPS-Pn films.