Synthesis, Structure, and Physical Properties of Hybrid Nanocomposites for Solid-State Dye Lasers

摘要

We report on the synthesis, structural characterization, physical properties, and lasing action of two organicuddyes, Rhodamine 6G (Rh6G) and Pyrromethene 597 (PM597), incorporated into new hybrid organic-inorganicudmaterials, where the organic component was either poly(2-hydroxyethyl-methacrylate) (PHEMA) or copolymersudof HEMA with methyl methacrylate (MMA), and the inorganic counterpart consisted of silica derived fromudhydrolysis-condensation of methyltriethoxysilane (TRIEOS) in weight proportion of up to 30%. Lasingudefficiencies of up 23% and high photostabilities, with no sign of degradation in the initial laser output afterud100 000 pump pulses at 10 Hz, were demonstrated when pumping the samples transversely at 534 nm withud5.5 mJ/pulse. A direct relationship could be established between the structure of the hybrid materials, analyzedudby solid-state NMR, and their laser behavior. An inorganic network dominated by di-/tri- substituted silicatesudin a proportion 35:65, corresponding to samples of HEMA with 15 and 20 wt % proportion of TRIEOS,udoptimizes the lasing photostability. The thermal properties of these materials, together with the high homogeneityudrevealed by atomic force microscopy (AFM) images, even in compounds with high silica content, indicateudtheir microstructure to be a continuous phase, corresponding to the polymer matrix, which “traps” the silicaudcomponents at molecular level via covalent bonding, with few or no silica islands.