Suppression of phase separation through blending of electron transporting materials in polymer electrophosphorescent devices

►The blue triplet dopant, FIrpic, aggregates in the active layer of the polymer light-emitting diodes. ►The aggregation is suppressed while the concentration of the electron transporting material, OXD-7, becomes higher. ►The “ambipolar”-nature of OXD-7 molecules can improve the compability between the host material and the dopant.