Polymer-based electroluminescent device with improved stability
AssigneeHewlett-Packard Company
InventorsDaniel B. Roitman, James R. Sheats, Mark R. Hueschen
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Abstract
An improved electroluminescent device which includes a hole injection electrode, an electron injection electrode, and an electroluminescent layer located between the hole and electron injection electrodes. The electroluminescent layer includes an organic polymer and a hindered phenolic additive in a concentration greater than 4% by weight. The preferred organic polymer is a derivative of PPV. The preferred hindered phenolic additives are and 2,4,6 tri-tert-butyl phenol 2,6 di-tert-butyl-methylphenol. The device has higher efficiency and a slower rate of degradation than devices lacking the hindered phenolic additive.
Claims5
An electroluminescent device comprising:
- a hole injection electrode;
- an electron injection electrode;
- and
- an electroluminescent layer comprising an organic polymer between said hole and electron injection electrodes, said electroluminescent layer further comprising a hindered phenolic additive in a concentration greater than 4% by weight, wherein said hindered phenolic additive is chosen from the group consisting of 2,6 di-tert-butyl-methylphenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, or 2,4,6 tri-butyl phenol.
An electroluminescent material comprising Poly(2,5-bis(5,6-dihydrocholestanoxy)-1,4-phenylene vinylene), and poly(2-methoxy- 5-(2-'ethyl-hexoxy)-1,4-phenylene vinylene) in combination with a hindered phenolic additive, wherein said hindered phenolic additive is chosen from the group consisting of 2,6 di-tert-butylmethylphenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, or 2,4,6 tri-tert-butyl phenol.
Dependencies are inferred from the claim text.