Electronic energy transfer between poly(9,9′-dihexylfluorene-2,2-dyil) and MEH-PPV: A photophysical study in solutions and in the solid state

Some aspects of the energy transfer processes between poly(9,9′-dihexylfluorene-2,2-dyil) and MEH-PPV in solutions of good and poor solvents and in solid state blends are addressed. The resonant non-radiative energy transfer in solution is discussed in terms of the Förster dynamic model and using steady-state and dynamical photoluminescence we observed that it is a very inefficient process, almost independently of the solvent. Also in solution the intensity decrease was discussed in terms of trivial energy transfer process. On the other hand, in solid state the resonant non-radiative energy transfer process is more relevant and strongly dependent on the MEH-PPV concentration in the blends. In this case, Förster approach may be relevant but it is not good enough to correlate the quenching efficiency with the blend composition. Trivial energy transfer process together with resonant energy transfer process play an important role for systems with donor higher concentration.