US EPA

5226148 

Journal Article 

Structural and photophysical aspects ot perylene- doped anthracene crystalline powders prepared by microwave heating 

Gharge, MN; Bhattar, SL; Kolekar, GB; Patil, , SR 

2008 

1 

Indian Journal of Chemistry. Section A
ISSN: 0376-4710
EISSN: 0975-0975 

NATL INST SCIENCE COMMUNICATION-NISCAIR 

NEW DELHI 

47 

11 

1642-1648 

English 

WOS:000261111200004 

The microwave assisted polycrystalline luminophors of anthracene have been prepared by addition of varying amounts of perylene dopant. The crystallanity and homogeneity of mixed crystals have been examined by scanning electron microscopy. The structural parameters such as grain size, microstrain, dislocation density and stacking fault in mixed crystal growth have been estimated as a function of perylene concentration. The mixed crystalline powders are fine grained. Increase in stacking fault indicates closely packed stacked structure of perylene-doped anthracene. The fluorescence studies show quenching of monomer fluorescence of anthracene by perylene dopant. Higher concentration of perylene generates exciplex in the excited state, which is observed in the form of a broad, structureless, red shifted band. The fluorescence quenching and exciplex formation have been explained on the basis of excitation energy transfer and molecular interaction between anthracene and perylene. The fluorescence characteristics of mixed crystals are described using Stem-Volmer kinetics. The fluorescence results are correlated with structural parameters.