Very high-mobility organic single-crystal transistors with in-crystal conduction channels

Very high-mobility organic transistors are fabricated with purified rubrene single crystals and high-density organosilane self-assembled monolayers. The interface with minimized surface levels allows carriers to distribute deep into the crystals by more than a few molecular layers under weak gate electric fields, so that the inner channel plays a significant part in the transfer performance. With the in-crystal carriers less affected by scattering mechanisms at the interface, the maximum transistor mobility reaches 18cm2∕Vs and the contact-free intrinsic mobility turned out to be 40cm2∕Vs as the result of four-terminal measurement. These are the highest values ever reported for organic transistors.