Simultaneous ultrafast probing of intramolecular vibrations and photoinduced charge carriers in rubrene using broadband time-domain THz spectroscopy

The ultrafast frequency- and time-resolved complex dielec. responses of photoexcited, single-crystal rubrene at n = 10-30 THz were detd. using ultrafast broadband far-IR spectra. In this frequency range, the responses of both photogenerated mobile charges and intramol. vibrational modes were obsd. simultaneously, both of which vary with time after excitation. The data in conjunction with a theor. model indicate a dynamic blueshift of the 15.5 THz phonon. [on SciFinder (R)]