Influence of the Emission Site on the Running Durability of Organic Electroluminescent Devices

Abstract

The influence of the emission site on the running durability of organic electroluminescent devices was examined. The fundamental device structure of [MgIn/BeBq_2/TPD/MTDATA/ITO] was employed. The dopant (rubrene) was doped in the TPD layer of device A and in the BeBq_2 layer of device B. The device C was non-doped device. The running lifetimes of devices A, B and C, in which the initial luminance was reduced to one-half under a constant driving current (5mA/cm^2), were 3554 h, 289 h, and 23 h, respectively. It was thus found that the emission site exerts an influence on the running durability.