We present solution-processable electron-transport layers (ETL) with highly enhanced electron-injection and electron-transport properties and resistance to oxygen and moisture for solution-processed organic light-emitting diodes (OLEDs). We selected polyethyleneimine ethoxylated (PEIE) as the ETL and Cs2CO3, CsF, and tris(8-hydroxyquinolinato)aluminum (Alq3) as n-type dopants. Compared with OLEDs with undoped PEIE as the ETL, the OLEDs with doped PEIE (d-PEIE) showed significantly improved luminance, efficiency, and lifetimes. These improvements are attributed to d-PEIE decreasing the work function of the Al metal cathode, as shown by ultraviolet photoelectron spectroscopy (UPS) analysis, and improving the gas and moisture resistance.
All Science Journal Classification (ASJC) codes
- Materials Chemistry