Focusing on charge-surface interfacial effects to enhance the laser properties of dye-doped nanoparticles

The synthesis of nanoparticles (NPs) for which only a single property is modified in a controlled manner is a challenge due to the fact that several physicochemical parameters are entangled. This letter assesses, from both experimental and theoretical points of view, the critical dependence on the charged-surface interfacial effect of the laser behavior in photonic nanomaterials based on dye-doped latexes without interference from other physicochemical parameters. When the dye and the NPs have similar charge nature, strong electrostatic repulsion prevents the dye molecules from being directly adsorbed in the surface and maintains the dye homogeneously distributed inside the NP, thus reducing deleterious interfacial effects. The highly homogeneous inner morphology leads to at least two-fold laser behavior enhancement of Rh6G in cationic NPs as compared with their anionic counterparts, and at least three-fold enhancement over Rh6G behavior in water solution. (letter)