Novel techniques in fabricating more efficient and brighter organic electroluminescent devices

In this paper, we present two techniques for fabricating efficient and bright organic light emitting devices. The first technique allows for an enhancement in the electron injection process. This is accomplished through inserting a layer of LiF with appropriate thickness between the cathode and a quinacridone doped organic layer. Devices with an Al/LiF cathode demonstrated a luminance in excess of 20,000 cd/m² and an external quantum efficiency of 3%, which is comparable to devices with a Mg/LiF cathode. These devices show maximum luminance of 45,000 cd/m² prior to failure in continuous bias operation. In the second technique, partially ionized beam deposition was utilized in the fabrication process of organic electroluminescent devices. Preliminary results indicate that devices fabricated with this technique are more efficient and brighter than similar devices fabricated with the traditional thermal evaporation process.