Covalent bonding effects on spectral, photophysical and generation properties of indocarbocyanine dyes in polyurethanes

Abstract Spectral, photophysical and generation properties of symmetrical cationic cyanine dyes have been investigated in the polyurethane matrices, similar by the structure, but different by the polymerization method. The cyanine dye doped polyurethane, synthesized by a polycondensation reaction, provides laser active elements with significantly improved photostability, efficiency and operation lifetime, compared to those for the polyurethane acrylate matrix, hardened by a radical photopolymerization method. Changing the liquid (ethanol) medium to polymers causes an increase of fluorescence quantum yield and efficiency. For the first time, covalent bonding between a cyanine dye and a polyurethane has been studied, and high fluorescence quantum yield and generation efficiency have been observed.