Spectroscopic characterization of red perylimide/surfactantnanocomposites

Abstract Novel photoluminescent materials formed bysome selected surfactants, metal derivatives of bis(2-ethylhexyl)sulfosuccinate (M(AOT)n; M = Na?, Co2?, Er3?and Yb3?), bis(2-ethylhexyl) amine (BEEA), bis(2-ethylhexy1)phosphoric acid (HDEHP) and a 1:1 BEEA/HDEHPmixture, doped with the red perylimide (ROT-300) havebeen prepared, and their optical properties have been testedby absorption spectroscopy and steady state and timeresolvedfluorescence. Experimental results show spectralshifts of the typical ROT-300 absorption and fluorescencebands with respect to that in apolar solvent medium. Dataanalysis leads consistently to attribute this feature mainly tothe freezing of the diffusive movement of the dye moleculesconfined in the nanodomains of the surfactant liquid crystals,whilst minor effects can be due to interaction with the surfactantpolar groups. Potentialities of these novel luminescentnanostructured composites as dye lasers, opticalamplifiers and solar concentrators have been highlighted. Inparticular, under optical pumping using a pulse laser,amplified spontaneous fluorescence emission of the ROT-300/HDEHP system above an excitation energy thresholdvalue of about 725 mJ cm-2 was observed.