Excimer-based white phosphorescent organic light emitting diodes with nearly 100 % internal quantum efficiency

Efficient excimer emission is demonstrated in white organic light-emitting diodes (see figure) based on platinum(II)[2-(4',6'-difluorophenyl)pyridinato-N, C-2')] (2,4-pentanedionato) utilized in devices incorporating the novel host material 2,6-Bis(N-carbazolyl)pyridine (26mCPy). External quantum (power) efficiencies of 15.9% (12.6 lm W-1) are realized at 500 cd m(-2).