PHOTOLUMINESCENCE STUDY OF C-60 DOPED POLYSTYRENE

We report here a new phenomenon in photoluminescence of C-60 doped in polystyrene. Under 488 nm cw laser radiation, the PL intensity of the sample was found to increase with time. With 10 h of irradiation, the PL signal strength increased by 10 times, comparable to that from poro us Si. The peak of the PL was found to shift to high frequency as well . More detailed studies showed that such an irreversible change of the sample might be a result of the lowering symmetry of oxidized C-60 fu llerene in the polystyrene. (C) 1996 American Institute of Physics.