Ballistic hole transport in pentacene with a mean free path exceeding 30 mu m

Low temperature ballistic hole transport in high-quality pentacene single c rystals is studied using macroscopic gated four-terminal van-der-Pauw geome try and two-terminal conventional field-effect transistor structures. Well- pronounced magnetic focusing peaks are observed in the magnetoresistance of van-der-Pauw samples indicating ballistic transport up to at least 45 mum. At low temperature the field-effect transistors show saturation currents i ndependent of the channel length and proportional to the channel width. The transistor characteristics are consistently analyzed assuming ballistic tr ansport of holes throughout the whole length of the channel. (C) 2001 Ameri can Institute of Physics.