Organic electroluminescent devices formed with rare-earth metal containing cathode
AssigneeCity University of Hong Kong
InventorsShuit-Tong Lee, Chun-Sing Lee, Shiu-Lun Lai, Mei-Yee Chan
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Abstract
There are disclosed rare-earth metal containing electron-injecting electrodes which are particularly effective for use with organic LED devices used in electroluminescent structures and which may in particular be formed as transparent electrodes for use in transparent or surface emitting OLEDs.
Claims21
An organic electroluminescent device comprising:
- a substrate formed of an electrically insulating material;
- a hole-injecting anode layer;
- an organic electroluminescent layer;
- and
- an electron-injecting transparent cathode comprising a rare-earth metal or a rare-earth metal alloy coevaporated with a conductive metal.
An organic electroluminescent device comprising a substrate formed of an electrically insulating material, a hole-injecting anode layer, an organic electroluminescent layer, and a cathode, wherein said cathode comprises a trilayer structure, comprising:
- an alkali fluoride or alkaline earth fluoride layer contacting the electroluminescent layer;
- a rare-earth metal layer contacting the fluoride layer;
- and
- a conductive layer contacting the rare-earth metal layer;
- the electroluminescent device having a turn-on voltage of less than about 2.5V.
The electroluminescent device as claimed in clam 13 wherein said fluoride layer is selected from the group consisting of magnesium fluoride, calcium fluoride, strontium fluoride, and barium fluoride.
Dependencies are inferred from the claim text.