Sensitised green emission in an electrically active polymer doped with a fluorinated acridine

The photophysical processes leading to sensitised green emission of a blend made by a host polymer poly(vinyl-carbazole) doped with a fluorinated acridine are investigated by means of steady-state and time-resolved luminescence. The large overlap between the donor emission and the acceptor absorption produces an efficient resonant energy transfer process from the host to the dye. At low dopant concentration, the dependence of the Fo¨ rster radius on the temperature is consistent with a thermally activated hopping process of the exciton within the donor prior to the resonant energy transfer to the acceptor. The activation energy for the hopping process is around 20 meV