Electroluminescence of green CdSe/ZnS quantum dots enhanced by harvesting excitons from phosphorescent molecules

Abstract

We demonstrated the enhancement of electroluminescence from green CdSe/ZnS quantum dots (QDs) in hybrid QD/organic light-emitting diodes (LEDs) by employing blue phosphorescent dyes bis(4,6-difluorophenylpyridinato-N,C2)picolinatoiridium (FIrpic) as efficient exciton harvesters and energy transfer donors. Precise control over the position and concentration of the donors doped in a fluorescent host led to complete exciton energy transfer from FIrpic molecules located within the Förster distance of ∼8 nm from the QD layer, and a 2.5-fold increase in the quantum efficiency of the QD-LEDs.