The fabrication of organic field-effect transistors (OFET) of a vacuum-sublimed polycrystalline pentacene films and calcium source-drain electrodes, was analyzed in an oxygen-free condition. The FET exhibited ambipolar characteristics and field-effect hole mobility of 4.5×19 -4 cm2/Vs and field-effect electron mobility of 2.7×10-5 cm2/Vs were also estimated from saturation currents. The appearance of electron enhancement mode in pentacene FET was found to depend on lowering of barrier for electron injection at source-drain electrodes. The results show that effective elimination of electron traps is essential requirement for observation of ambipolar behavior in pentacene.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)