P‐182: Lifetime Enhancement by Fabrication of a Doped Graded‐emission Layer in Organic Light‐emitting Diodes

Abstract

We report an improved doped graded-emission layered structure (IG-EML) which can be readily fabricated by a conventional research thermal-evaporation coater and enhance device lifetime. This is demonstrated by doping fluorescent yellow emitter EY53 in the host matrix formed by programmed continuous mixing of a typical hole transporting material (e.g. NPB) and an electron transporting material (e.g. BAlq). Compared with the conventional bi-layer (B-EML), mixed-emission (M-EML) and a typical graded-emission (G-EML) device, the novel IG-EML doped OLEDs offer significant advantage in operational device stability T 50 (more than 4.8 times than that of the B-EML structure) without compromising its current efficiency.