Ambipolar organic field-effect transistors based on rubrene single crystals

We herein report ambipolar organic field-effect transistors based on rubrene single crystals. The transistors operate in both the $p$- and $n$-channel regimes depending upon the bias conditions. Hole and electron mobilities of 1.8 and $1.1×10−2cm2∕Vs$⁠, respectively, were derived from saturated currents. The appearance of an electron enhancement mode in single crystals of wide-band-gap semiconductors $(∼2.6eV)$ is ascribed to the reduction of electron traps at the semiconductor-dielectric interface using a hydroxyl-free gate dielectric.