Fast photorefractive effect in PVK:C₆₀:DEANST polymer composite

The photorefractive effect is observed and described in a polymeric composite consisting of poly [N-vinylcarbazole] charge transporting matrix, fullerene C₆₀ photosensitizing molecules, and second-order active molecules of (diethylamino)nitrostyrene. The results of photoconductivity, electrooptic modulation, degenerate four-wave mixing, and two-beam coupling experiments are reported. The composite shows relatively high field-dependent electrooptic coefficient and charge carrier photogeneration quantum efficiency. The observed photorefractive diffraction efficiencies compare well with those of well-known inorganic materials. Time-dependent measurements reveal very fast kinetics of light induced phase grating formation and erasure. A possibility of efficient switching of the photorefractive effect with an external electric field is shown.