High Performance Green Fluorescent Organic Electroluminescent Devices with Double Light-Emitting Layers

摘要

Recently, organic single crystal thin film attracted great interest throughout the world. Compared with amorphous materials, organic crystal possessed unique superiority due to their potential applications in optoelectronic devices, such as high stability, ordered structures and high charge mobility. In this work, we aim to further improve the electroluminescent (EL) performances of green emitter N,N’dimethyl-quinacridone (DMQA) by designing double light-emitting layers (EMLs) devices. Then, a series of EL devices with different EMLs were designed and fabricated by vacuum evaperation. Compared with single-EML devices, these double-EMLs devices showed higher efficiency and brightness attributed to carriers’ balance and wide recombination zone. Finally, green EL device (Commission Internationale de l’Eclairage (CIE) coordinates of (0.31, 0.61)) with maximum current efficiency, power efficiency and brightness up to 12.92 cd/A (external quantum efficiency (EQE) of 3.4%), 11.47 lm/W and 21028 cd/m2, respectively, was obtained.