Study on Electron Injection Effect of Low Molecular Organic Light-Emitting Diodes Utilizing LiF/Al and Li/Al Cathode

摘要

The electron injection effects of organic light-emitting diodes (OLED) from the cathode interface between LiF or Li and Al on the tris-(8-hydroxyquinolinato) aluminum (Alq{sub}3) emissive layer have been investigated. Efficient electron injection was achieved in the case of thin layer of LiF or Li deposited on Alq{sub}3 emissive layer at the thickness of 0.5nm and 2nm, respectively. The results indicate that the coexistence of LiF and Al layer or the Li and Al layer on the Akq{sub}3 emissive layer result in the efficient electron injection. Electron injection effect in the case of LiF/Al and Li/Al electrode configurations and also the effect of air explosion during the electrode formation have been discussed. In the case of the device with Li, the diffused Li in the Al layer acts as the efficient carrier injection process.