Field-Effect Studies on Rubrene and Impurities of Rubrene
24 January 2006
Rubrene single crystals have been grown by a vapor phase process. Two additional molecules, which contaminate rubrene have been identified and their structures determined. Single crystals of Rubrene show excellent crystallinity and very small rocking curve width. Field effect transistors based on pure rubrene single crystals with colloidal graphite electrodes and parylene as a dielectric demonstrate a maximal mobility of 13 cm2/Vs. A strong anisotropy of the mobility has been measured. The mobility increases very slightly with cooling but decreases significantly at low temperatures.