DEPHASING PROCESSES OF COHERENT EXCITON MIGRATION IN MIXED AGGREGATESWITH BARRIERS OF PIC-I AND AZAPIC-I

Coherence decay processes of Frenkel excitons in the mixed aggregates with barriers at low temperature were investigated using an accumulate d photon echo technique. The lengthening of the dephasing times T-2 wi th increase of the molar fraction of azaPIC-I was observed, which is c ontrary to the shortening of T-2 in the mixed aggregate with traps. Ex citon coherence lengths were studied theoretically and experimentally. It is demonstrated that the effective distance, passed through by exc itons, is less than the exciton coherence length.