The doping effect of cesium compounds (i.e., Cs2CO3, CsN3 and CsF) doped electron injection layer (EIL) on charge transport properties and operational stability of organic light-emitting diodes (OLEDs) was systematically investigated in this work. It has been found that device characteristics and lifetime are highly dependent on the doping constituent materials. The doping of cesium compounds in EIL can improve the charge injection and transport of OLEDs, due to the increase in conductivity and reduction in electron injection barrier. Apart from the difference in electrical characteristics, the operational stability of OLEDs is strongly influenced by the doping mechanism of different cesium compounds in the EILs. The OLED device using Cs2CO3 as the n-type dopant for the EIL shows a superiority in both electrical property and operational lifetime.
- Cesium compounds
- n-Type dopant
- Operational stability
- Organic light-emitting diodes