Recent advances in solution-processed organic and perovskite nanocrystal light-emitting devices

This paper outlines recent progress in various solution-processed fluorescent polymer tandem organic light-emitting diodes (OLEDs), white phosphorescent tandem OLEDs, and perovskite nanocrystal (NC) LEDs. Tandem OLEDs, which comprise multiple light-emitting units stacked in series through a charge-generation layer, have attracted considerable attention for display applications owing to their high efficiencies and long operational lifetimes. In addition, a nine-layered tandem OLED structure is produced by using a solution process, wherein appropriate coating solvents are carefully selected for each layer. In recent years, metal halide perovskite NCs have also been considered promising light-emitting materials owing to their excellent optoelectrical properties. Herein, the perovskite NC surface was modified by reprecipitation and gel permeation chromatography purification processes, which resulted in enhanced optoelectrical and LED performance.