Pentacene is a promising molecule for application as an organic semiconductor.(1-5) Because of its high degree of crystallinity in the solid state, pentacene has high charge carrier mobility in thin films, and therefore it is an ideal p-type semiconductor in organic thin-film transistors (OTFT).(1-5) Thin films of pentacene show mobilities greater than 1.5 cm 2 /(V s),(6) and even values greater than 5 cm 2 /(V s)(7) have been reported. The mobility depends critically ...