Enhanced performance of perovskite light-emitting-diodes based on ionic liquid modified CsPbBr3 nanocrystals

Abstract Perovskite nanocrystals (NCs) are promising materials for light-emitting diodes (LEDs) owing to their unique optoelectrical properties. However, the organic long-chain ligands act as insulating layers on NC surface, causing the low carrier transport capability and poor performance of LEDs. Herein, a novel strategy was proposed to facilitate the carrier transport for enhancing the performance of perovskite light emitting diodes (PeLEDs). Ionic liquid (IL) 1-ethyl-3-methylimidazolium bromide [Emim]Br was introduced into the synthesis process of CsPbBr3 NCs, which could improve the emission intensity of NCs significantly. Furthermore, [Emim]Br also possessed the characteristic that facilitated the transportation of carriers, resulting in the enhancement of external quantum efficiency (EQE) of PeLEDs from 0.38% to 1.03%. These results demonstrate that the novel strategy opens up new avenue for boosting the PeLED performance, which will promote the commercial applications in future high-definition displays.