Solution-processed sky-blue phosphorescent organic light-emitting diodes based on 2-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene-8-yl)-4-(trimethylsilyl)pyridine chelated iridium complex

A new 2-(5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene-8-yl)-4-(trimethylsilyl)pyridine-based iridium complex was synthesized for efficient solution-processed sky-blue phosphorescent organic light-emitting diodes (PhOLEDs). The effect of dioxaboranaphthoanthracene instead of phenyl with the electron-accepting group, as well as the bulky pyridine with the trimethylsilyl group, on the ligand was investigated. The new dopant was found to have an extremely high photoluminescence quantum yield of 94% when doped in an emissive layer. As a result, the solution-processed blue PhOLED consisting of a simple structure without any interlayer exhibited remarkable light-emitting performance with an external quantum efficiency of 8.93% and a current efficiency of 23.56 cd/A.