Enhancement of efficiency of multilayer polymer light-emitting diodes by inserting blocking layers

► Multilayered structures have been developed for improving the efficiency of OLED. ► Insertion of blocking layers is one of the effective methods for enhancing the efficiency of OLEDs. ► For a PLED, it is hard to find a solvent which is immiscible with the material of the bottom layer. ► In this study, multilayer PLEDs were fabricated by spin-coating and thermal evaporation. ► The efficiency of a PLED with a dual-blocking layer is increased by 2.37 times.