Hall-effect mobility of pentacene films prepared by the thermal evaporating method with different substrate temperature

We studied the Hall-effect mobility of pentacene films prepared by the thermal evaporating method with different substrate temperature. A crossover from coherent bandlike charge transport with mobilities up to several tens of cm(2)/V-s at low temperature to an incoherent hopping motion at high temperature is observed. The carrier mobilities of pentacene exhibit a hopping-to-band transition around room temperature. An exhibition of high mobility of pentacene films prepared with substrate temperature of 90 degrees C is attributed to the increased spacing between molecules. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4733293]