Abstract
The electron injection process, which limits the electroluminescent performance of organic devices, has been enhanced tremendously by 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. For the same LiF thickness, the operating voltage for devices with Al/LiF was lower than the corresponding operating voltage for devices with Mg/LiF or Mg alone. Tunneling theory is used to explain this enhancement.
Original language | English (US) |
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Pages (from-to) | 1762-1764 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 71 |
Issue number | 13 |
DOIs | |
State | Published - Sep 29 1997 |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)