Efficient Green Fluorescent Organic Light-Emitting Devices with Stepwise Energy Levels

Abstract

Abstract In our work, efficient devices with double-EMLs with step energy based on green fluorescent emitter C545T were reported. Due to the matched energy, TcTa and 26DCzPPy were selected as the host materials of double-EMLs. The devices with double-EMLs displayed more excellent EL efficiency and higher brightness compared with devices with single-EML, which attributed to better balance of carriers, broadening recombination zone. Finally, efficient green EL device obtained maximum CE, EQE, PE and brightness of 10.13 cd/A, 2.8%, 9.36 lm/W and 11490 cd/m2.