High-density electrostatic carrier doping in organic single-crystal transistors with polymer gel electrolyte

High-density carrier accumulation in organic semiconductors is demonstrated in Au/polymer gel electrolyte/rubrene crystal/SiO2/doped Si dual-gate transistors, forming electric double layers in the polymer gel. Application of only 1.2 V across the polymer gel electrolyte drastically enhances the conductance of the rubrene single crystal with the field-induced carrier density up to similar to 5x10(13) cm(-2). Directly comparing the transfer characteristics of the same device channel in the dual-gate transistors revealed that the achieved doping level is beyond the maximum of the SiO2-based transistor on the opposite side of the organic crystal. (c) 2006 American Institute of Physics.