Improvement of electron-hole injection balance in Si-anode organic light-emitting diodes by using enhanced electron injection organic of fluorinated tris-(8-hydroxy-quinolinato) aluminum

摘要

A novel fluorinated organic compound of 5-F-tris-(8-hydroxy-quinolinato) aluminum (5FAlq3) with a higher electron affinity was used as the electron-transporting material in Si-anode organic light-emitting diodes (SAOLEDs). The experimental results showed that 5FAlq3 could decrease the device electron injection barrier due to its higher electron affinity than tris-(8-hydroxy-quinolinato) aluminum (Alq_3), thus enhance the electron injection. The power efficiency of the device increased to 0.462 lm/W from 0.029 lm/W via the use of 5FAlq_3 instead of Alq_3, and the concomitant insertion of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) as well as optimization of the device structure. The approach provide a strategy to solve the current problem of hole-electron injection imbalance in SAOLEDs.