Efficient white polymer light-emitting diodes (WPLEDs) based on double emitting layers of a PVK:Eu( iii )-complex and Alq3

Elaborated from the dEML-configured structure for WPLEDs with low turn-on voltage (6.0–7.5 V) and weak efficiency-roll-off, their efficiencies ( η c = 0.32–0.39 cd A −1 , η EQE = 0.54–0.56% and η p = 0.99–1.10 lm W −1 ) represent the record values of organo-Eu 3+ -incorporated WPLEDs.