PERCOLATION OF TRIPLET EXCITATION IN SOL-GEL MATRIX

Triplet spectroscopy and energy migration among benzophenone chromopho res have been studied in sol-gel matrix under steady state excitation. The energy migration process was observed by the rise of sensitised e mission from tripler energy accepters like, 1,4-dibromonaphthalene and 1-chloronaphthalene after excitation of benzophenone chromophore. The probability of donor excitation energy capture by the trap shows a cr itical concentration dependence on the benzophenone molecules. The per colation model has been applied to evaluate the critical exponents. Th e evaluated critical exponents are in very good agreement with three d imensional excitation transport. Copyright (C) 1996 Elsevier Science L td