Air-stable ambipolar organic transistors

The authors report on ambipolar organic transistors based on the soluble dithiolene derivative (diphenylethylenedithiolato)(1,3-dithiol-2-thione-4,5-dithiolato)nickel Ni(dpedt)(dmit). Due to its small band gap, efficient injection of holes and electrons from gold source/drain electrodes is possible. Both carrier mobilities are estimated to be approximately equal with maximum value on the order of 10−4cm2∕Vs. The transistors exhibit excellent ambient stability with a shelve lifetime exceeding 3months. The pronounced stability of Ni(dpedt)(dmit) as well as of several other molecules studied here is correlated to their redox potential. The present findings can be used as a general guide towards design and synthesis of air-stable ambipolar/n-channel molecules.