Air-stable Inverted Organic Light-emitting Diodes

Abstract

We propose an air-stable organic light-emitting diode (OLED) using an inverted OLED. We have developed a practical OLED using the “iOLED” structure consisting of a two-layered electron injection layer (EIL) with a WVTR of 10^-4g/m²/day. The initial EL characteristics of a conventional OLED and the iOLED are almost the same under the condition of practical use. No dark spot formation or shrinkage was observed after 250 days in the iOLED. And the operational stability of the iOLED is greatly superior to that of a conventional OLED using the red phosphorescent material Ir (piq)₃. Finally, we successfully fabricated the flexible AMOLED display using the iOLEDs.