Electron-Induced Quenching of Excitons in Luminescent Materials

We studied photoluminescence (PL) behavior of tris(8-hydroxyquinoline) aluminum based organic light-emitting devices doped with various fluorescent dyes, under electron currents. The results show that electron currents reduce the PL quantum yield by as much as 50%, depending on the electron density and the doping conditions in the emitter layer. The decrease in luminescence under electron current indicates electron−exciton interaction, which likely plays a role in limiting the efficiency of organic electroluminescent devices.