Fig. 2.

Replicating bulk and solution spectra in dilute matrix environments at room temperature. (A) The ensemble spectrum of chains dispersed in the inert Zeonex matrix (green) closely matches that of isolated chains in toluene (gray). In contrast, PMMA leads to chain aggregation: the spectrum of P3HT diluted in PMMA at the same concentration as in Zeonex (red) resembles the bulk film emission (gray). In both cases, the concentration of P3HT is 100 times higher than in single-molecule experiments. (B) The effect of matrix-induced phase separation is visible in fluorescence micrographs of the spin-coated films, plotted on the same intensity scale. In Zeonex, the film PL appears uniform, whereas in PMMA bright spots are seen corresponding to the formation of large multichain aggregates.