Luminescent quantum yields and vibrational spectroscopy

The luminescent quantum yield of organic materials is strongly determined by their local environment. This is illustrated for the case of Anthracene and Terphenyl in a range of solvents. Although weak solvato-chromatic shifts of the absorption and luminescence spectra are observable, they do not account for the dramatic variation in luminescent quantum yields. The results suggest that the quantum yields are dictated by the nonradiative processes, particularly the correlation of the vibrational structure of the chromophore with that of its local environment. This is illustrated using a Raman spectroscopy, and the implications on the prospect of controlling the quantum yields of organic materials in the solid state are discussed.