Red Efficient Perovskite Light-Emitting Diodes Assisted with PEIE

Perovskite light-emitting diodes (PeLEDs) exhibit broad application potential in lighting and display technologies. The quality of the perovskite film is crucial in determining the device's performance. The introduction of organic polymer additives has been shown to enhance the performance of PeLEDs. In this study, we introduced a polyethylenimine (PEIE) additive into the perovskite precursor solution to modulate the crystallization process and passivate defects of perovskite films. Smooth and dense perovskite films accompanied by enhanced optoelectronic properties and reduced trap state density were obtained. As a result, the maximum external quantum efficiency (EQE) of the red PeLEDs using the PEIE additive reaches 16% at 670 nm. At a constant current density of 100 cd/m2, the half-life of the device can reach 13.2 h. The devices also exhibit good thermal stability. This work provides a practical approach for manipulating efficient perovskite crystal growth and defect passivation of PeLEDs.