High charge carrier densities and conductance maxima in single-crystal organic field-effect transistors with a polymer electrolyte gate dielectric

Abstract

High charge carrier densities have been realized in organic field-effect transistors based on single crystals of the organic semiconductors rubrene and tetracene using a high capacitance polymer electrolyte gate dielectric. The source-drain current was modulated by five orders of magnitude in a rubrene single-crystalorganic field-effect transistor (SC-OFET) with gate voltages ranging from 0 to − 3 V . A peak in the field-effect conductance was also observed in SC-OFETs at induced carrier densities of ∼ 10 15 charges ∕ cm 2 . Key to successful devicefabrication was the introduction of a thin, insulating spacer layer between the organic single crystal (OSC) and the polymer electrolyte gate dielectric. Further improvement of the devicefabrication procedure may eliminate suspected solvent-related degradation effects and raise mobility values in these SC-OFETs, opening the door to a wide spectrum of experiments on OSCs at high charge carrier densities.