W. Humbs et al., Sub-picosecond fluorescence dynamics of organic light-emitting diode tris(8-hydroxyquinoline) metal complexes, CHEM P LETT, 304(1-2), 1999, pp. 10-18
For a few complexes belonging to a new class of organic Light-emitting diod
es (OLED), namely Al(III)- and Ga(III)-tris-8-hydroxyquinoline (Alq(3) and
Gaq(3)), femtosecond fluorescence up-conversion measurements are reported.
The fluorescence decays contain picosecond components when the complexes ar
e dissolved in liquid solution. The fast components are not found in the ti
me-resolved fluorescence of the complexes doped in an inert host crystal. T
he results in liquid solution are characteristic of a dynamic Stokes shift
due to the solvation in a Ligand-localized excited state. Furthermore, from
the temporal behavior of the total fluorescence intensity it is concluded
that, concomitant with solvation, adiabatic electron transfer takes place.
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