Fabrication of organic electroluminescence device with ion beam-assisted deposition of ultrathin lithium fluoride as a hole injection layer

An ultrathin lithium fluoride (LiF) hole injection layer was deposited on an indium-tin-oxide (ITO) anode by an ion-beam-assisted deposition (IBAD) technique to fabricate an organic electroluminescence device. The device with the LiF layer deposited by this method has higher external quantum efficiency than a device with a LiF deposited by conventional thermal evaporation. Moreover, the hole-injection ability of the device prepared by IBAD is better than that of the device produced by a conventional method such as thermal evaporation. It is found that the surface of the LiF layer prepared by IBAD has high surface coverage on an ITO anode because the LiF layer prepared has high adatom mobility due to the ion beam energy.