Infrared spectroscopy on the charge accumulation layer in rubrene single crystals

To get access to the intrinsic properties of organic semiconductors, investigations on single crystals are essential. The authors report on far- and mid-infrared spectroscopies of the charge accumulation layer in an organic field-effect transistor fabricated on a rubrene single crystal. By charge modulation spectroscopy in the range between 70 and 4750 cm(-1), they were able to detect the Drude response of the accumulated charges in the channel. From this they can extract important intrinsic transport parameters such as the mobility, the plasma frequency, the effective mass, and the scattering rate. (c) 2006 American Institute of Physics.