Blue-Light-Emitting Organic Electroluminescent Devices with Oxadiazole Dimer Dyes as an Emitter

Abstract

Multilayer thin-film electroluminescent devices with blue emission color have been fabricated using new oxadiazole dimer dyes for both emission and electron transport layers. Emission characteristics of three types of cells, SH-A: ITO/HTL/EML/MgAg, SH-B: ITO/EML/ETL/MgAg and DH: ITO/HTL/EML/ETL/MgAg, in which ITO, HTL, EML, ETL and MgAg represent indium-tin-oxide cathode, hole transport layer, emission layer, electron transport layer and magnesium-silver alloy anode, respectively, are compared. Luminances exceeding 1000 cd/m² are observed and emission peaks are located at 470-480 nm. Among the three cells, the DH cell shows the best performance. The DH cell is stable for more than 40-day storage and can also be continuously driven for more than one hour at room temperature and 7 h at liquid nitrogen temperature.