High-Efficiency Phosphorescent OLEDs using Chemically Doped Layers

Abstract

Organic light-emitting devices (LEDs) were fabricated using wide-energy-gap (over 3.30 eV) materials and fac-tris(2-phenylpyridine) iridium complex (Ir(ppy)3) as the carrier transporting materials and the emitting material, respectively. The organic layers at the electrode interfaces were chemically doped to reduce operating voltage. The p-type and n-type doped layers have specific resistance of 105∼106 ω [SW1]·cm. The device exhibited green emission peaking at approximately 510 nm, and the external quantum efficiency of 19.7% (69 cd/A). A high power efficiency of 68 lm/W was observed at 100 cd/m2 at voltage of 3.22 V.