Synthesis and Photophysical Properties of Multichromic Nanocrystals of Polymethine Dyes

A unique method for the self-assembly of multilayer multichromic molecular crystals from three various polymethine dyes absorbing light in the broad spectral range has been developed. This method is based on the formation of an anionic platform of J-aggregates of magnesium complexes of thiamonomethinecyanines in an aqueous solution followed by the matrix synthesis of J-aggregates of two cationic trimethinecyanines on the surface of the platform. Spectral, luminescent, and photoelectric properties of the multichromic crystals of dyes have been studied. It has been shown that each multichromic organic crystal is a multilayer photoelement which possesses photoconductivity in three maxima of exciton absorption in the blue, green, and red spectral ranges with efficiency from 2.7 to 6.1%. The results form the basis for the technological development of high-organized molecular structures possessing unique optical and photoelectric properties with the aim of applying them in organic and hybrid organic/inorganic photonics and optoelectronics, including in the form of thin-film photoconverters in broad spectral ranges.