FAST PHOTOREFRACTIVE EFFECT IN PVK-C-60-DEANST POLYMER COMPOSITE

The photorefractive effect is observed and described in a polymeric co mposite consisting of poly [N-vinylcarbazole] charge transporting matr ix, fullerene C-60 photosensitizing molecules, and second-order active molecules of (diethylamino)nitrostyrene. The results of photoconducti vity, electrooptic modulation, degenerate four-wave mixing, and two-be am coupling experiments are reported. The composite shows relatively h igh field-dependent electrooptic coefficient and charge carrier photog eneration quantum efficiency. The observed photorefractive diffraction efficiencies compare well with those of well-known inorganic material s. Time-dependent measurements reveal very fast kinetics of light indu ced phase grating formation and erasure. A possibility of efficient sw itching of the photorefractive effect with an external electric field is shown.