Enhanced Efficiency Roll-Off and Driving Voltage in Hybrid Blue Organic Light-Emitting Diodes with Triplet Harvesting and Mixed Host System

We present the systematic study of a triplet harvesting (TH) mechanism and a mixed host system in the emission layer (EML), which affects the enhanced efficiency roll-off and driving voltage of hybrid blue organic light-emitting diodes (HB OLEDs). The HB OLEDs are fabricated with 1,6- Bis(N-phenyl-p-CN-phenylamino)-pyrenes and bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate as blue fluorescent and phosphorescent emitters within the EML. The …