The effect of cyanine dyes on photorefractive properties of composites based on carbon nanotubes

Abstract

Photorefractive, nonlinear optical, and photoelectric characteristics at 1064 nm are discussed in the case of composites of polyvinyl carbazole (PVC) and closed single-walled carbon nanotubes with an additive of a visible-range cyanine dye with high electron affinity. Photorefractive properties are due to carbon nanotubes that are simultaneously spectral sensitizers toward laser irradiation at 1064 nm and responsible for the third-order dielectric susceptibility. Introduction of the dye leads to an increase in the photorefractive two-beam amplification factor of the laser bean and a significant increase in the quantum efficiency of free hole formation in PVC, but also a decrease in the third-order susceptibility. The dye plays the role of a super-sensitizer. It probably limits charge recombination in geminal pairs photogenerated in the range of bright interference fringes.