Organic Light-Emitting Diodes with Ir-Based Phosphorescent Dopants

Abstract

We have characterized and synthesized a phosphorescent dopants with methyl groups on a phenyl, pyridine part of main ligand, and picolinate acillary ligand to increase intermolecular interaction to give reduced quenching effect. The synthesized dopants showed high thermal stability about 400 oC by thermogravimetric analysis with fluorocarbon-substituted compounds, which has very inductively electron-withdrawing. Although the OLEDs with Ir-based dopants showed relatively low device efficiency from 0.62 to 1.53 cd/A, it had the uniform, pinhole-free, and optical band gap for an efficient dopant.