The influence of various polymeric matrices on the phosphorescence of organic molecules is illustrated for the case of 1, 2, 5, 6-dibenzanthracene. The phosphorescence spectra and decay times are compared with low-temperature glasses. Interaction of the aromatic hydrocarbon with the plastic matrices is shown to be greater than with the low-temperature glasses. This interaction is manifested by a higher quantum yield of phosphorescence (relative to fluorescence), but shorter decay times. The effect of the polymer on the triplet state is interpreted in terms of the vibrational structure of the phosphorescence spectra. The degree of polarization and decay time of the phosphorescence emission was studied in the range 77°-365°K and the results are related to the temperature dependence of rotation of the molecule in the matrix. The quenching action of oxygen on phosphorescence is demonstrated with film samples of 20-µ thickness.
The relevant physical properties of the plastics employed are discussed and details of sample preparation are presented.
NICHOLAS GEACINTOV, GERALD OSTER, and THOMAS CASSEN, "Polymeric Matrices for Organic Phosphors," J. Opt. Soc. Am. 58, 1217-1228 (1968)