Selectively patterned highly conductive poly(3,4-ethylenedioxythiophene)-tosylate electrodes for high performance organic field-effect transistors

We have improved the performance of pentacene field-effect transistors by using highly conductive poly(3,4-ethylenedioxythiophene)-tosylate (PEDOT-Tos) source-drain electrodes (similar to 10(3) S/cm) formed by a simple solution-based process. A high field-effect mobility of 0.25 cm(2)/Vs and an ON/OFF current ratio of 10(7) were obtained in pentacene-based bottom contact organic field-effect transistors (OFETs), which constitutes an improvement over OFETs based on Au and PEDOT:PSS electrodes. Two-dimensional grazing incidence x-ray diffraction and ultraviolet photoemission spectroscopy results confirmed that the crystalline properties of the pentacene film and the hole injection from the PEDOT-Tos electrode to the pentacene layer are more efficient than those from Au and PEDOT: PSS electrodes. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3273862]