High mobilities in organic semiconductors: basic science and technology

High quality single crystals of a variety of molecular organic semiconductors have been investigated in the temperature range from 1.7 to 500 K in order to study the charge transport anti to reveal the intrinsic limits for electronic applications. Room temperature (RT) mobilities are typically in the range of 1 cm(2)/Vs increasing with decreasing temperatures. At lowest temperatures, however, electron as well as hole mobilities exceeding 10(3) cm(2)/Vs can be observed. Hence, it is possible to observe the Fractional Quantum Hall effect in two-dimensional electron or hole gases in materials such as tetracene or pentacene. Moreover, we were able to transform these materials into a superconducting state below 2 K by applying a high gate bias. In addition, the intrinsic performance limits of organic field-effect transistors (FETs) were investigated. Single crystal devices exhibited mobilities up to 5 cm(2)/Vs, on/off-ratios exceeding 10(8), and sub-threshold slopes below 200 mV per decade. (C) 2001 Elsevier Science B.V. All rights reserved.