High-Performance Quantum Dot-Light-Emitting Diodes with a Polyethylenimine Ethoxylated-Modified Emission layer

ABSTRACT Colloidal quantum dots (QDs) are emerging as one of the most promising candidates due to their unique optical and physical properties. Solution-processed QD-based light-emitting diodes (QLEDs) have been extensively studied and developed for next-generation displays and solid-state lighting. The most practical approach to improve device performance is to optimize charge transport and charge balance in the recombination region. Here, we applied polyethylenimine ethoxylated (PEIE) with low-work function modifiers on top of the quantum dot emissive layer to reach a better charge balance and devices was characterized. Our QLED with a 5.4 nm PEIE layer exhibited a maximum luminance of 41,440 cd/m2 and current efciency of 4.9 cd/A, which are signifcantly more than 2.3 times greater than that of QLED without PEIE.