Electric field and charge induced quenching of luminescence in electroluminescent emitters based on lanthanide complexes

We have investigated strong photoluminescence quenching (over 50%) in an important class of line-like emitters (organolanthanides) by measuring the time-resolved emission from their films to which increasing fields up to 2.7 MV/cm have been applied. By manipulating the electrode materials and their electrical bias, we have been able to show that two mechanisms are equally effective in reducing the emission quantum yield, namely (i) the electric field-enhanced dissociation of the ligand precursor excited states of the emissive lanthanide ion states, and (ii) the interaction of the precursor states with the field-increasing charge injected from electrodes into the films. (C) 2008 Elsevier B.V. All rights reserved.