73‐4: Novel Materials and Structures for High Efficiency and Long Lifetime Green Phosphorescent OLEDs in Automotive Applications

Abstract

A long lifetime and high efficiency organic light emitting diode (OLED) was developed with optimization of each organic materials. We improved the operational lifetimes of the green photphorescent OLEDs based on the balance beween hole and electron inside the emission layer (EML) affects the lifetime of OLEDs. The operational lifetimes become long with increasing the density of hole carrier in the EML. For that purpose, we fabricated with using the new electron blocking layer (EBL) and hole blocking layer (MBL) and optimized the thickness of EML. The lifetimes of the green phosphorescent OLEDs developed in this study were achieved over −2.6 times better lifetimes at room temperature than that of reference device. Finally, this green phosphorescent OLEDs are fabricated for mass production of automotive application.