Effect of the Thickness of the Lithium Quinolate and Aluminum Mixed Layer Acting as an Electron Injection Layer on the Efficiency of Organic Light-Emitting Devices

Abstract

The thickness of the lithium quinolate and aluminum mixed layer acting as an electron injection layer in organic light-emitting diodes (OLEDs) was optimized to enhance the efficiencies of OLEDs. The electrical properties of OLEDs with a mixed layer were compared with those of hole-rich or electron-only devices. The current densities of OLEDs with a mixed layer were lower than those of OLEDs without a mixed layer. The luminance efficiencies of OLEDs with a mixed layer were higher than those of OLEDs without a mixed layer due to an increase in electron current and a decrease in hole current, resulting in achieving more balance of electrons and holes in an emitting layer.