Phenothiazine based nanocrystals with enhanced solid state emission.

The paper focuses on the preparation of phenothiazine based nanoparticles, both in liquid and solid states, by reprecipitation in water and solvent induced phase separation respectively. Polymethylmethacrylate was used as an inert matrix and polyfluorene as a luminescent matrix. The morphological features of the nanoparticles were investigated by dynamic light scattering, and SEM, AFM and POM microscopy, which revealed their supramolecular ordering as nanocrystals. Their photophysical behaviour was monitored by UV–vis and photoluminescence spectroscopy. The nanocrystals emitted green light, with higher efficiency compared to the bulk crystals, reaching an absolute quantum yield of 35% in water, 45% in polymethylmethacrylate, and 39% in polyfluorene. [ABSTRACT FROM AUTHOR]