US5059861A
Expired / Lapsed
US
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Organic electroluminescent device with stabilizing cathode capping layer
Assignee: Global OLED Technology LLC
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Filing: 1990-07-26
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Granted: 1991-10-22
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Expires: 2010-07-26
Abstract
Abstract An organic electroluminescent device is disclosed which is protected from dark spot formation. The device is comprised of, in sequence, a support, an anode, an organic electroluminescent medium, and a cathode containing a plurality of metals other than alkali metals. The cathode is comprised of a capping layer containing at least one alkaline earth or rare earth metal and, interposed between the capping layer and the organic electroluminescent medium, an electron injecting layer containing at least one metal having a work function of less than 4.0, but exhibiting a higher work function than the alkaline earth or rare earth metals in the capping layer.
Inventors
- 👤 Jon E. Littman
- 👤 Michael Scozzafava
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:45
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/06; H; H05; H05B; H05B33/00; H05B33/12; H05B33/14; H05B33/26; H10; H10K; H10K50/00; H10K50/10; H10K50/17; H10K50/171; H10K50/80; H10K50/805; H10K50/82; H10K50/826; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
An organic electroluminescent device comprised of, in sequence, a support, an anode, an organic electroluminescent medium, and a cathode containing a plurality of metals other than alkali metals, characterized in that said cathode is comprised of a capping layer containing at least one alkaline earth metal having a work function of less than 3.5 eV or rare earth metal having a work function of less than 3.5 eV and interposed between said capping layer and said organic electroluminescent medium, an electron injecting layer containing at least one metal having a work function of less than 4.0, but exhibiting a higher work function than said alkaline earth or rare earth metals in said capping layer.
Claim 2
Dependent Claim
114 words
An organic electroluminescent device comprised of, in sequence, a support, an anode, an organic electroluminescent medium, and a cathode containing a plurality of metals other than alkali metals, characterized in that said cathode is comprised of a capping layer containing at least one alkaline earth metal having a work function of less than 3.5 eV or rare earth metal having a work function of less than 3.5 eV and interposed between said capping layer and said organic electroluminescent medium, an electron injecting layer containing at least one metal having a work function of less than 4.0, but exhibiting a higher work function than said alkaline earth or rare earth metals in said capping layer.
Claim 3
Dependent Claim
23 words
An organic electroluminescent device according to claim 1 further characterized in that said capping layer has a thickness of at least 500 Å.
Claim 4
Dependent Claim
23 words
An organic electroluminescent device according to claim 2 further characterized in that said capping layer has a thickness of up to 10 μm.
Claim 5
Dependent Claim
29 words
An organic electroluminescent device according to claim 3 further characterized in that said capping layer has a thickness in the range of from about 1000 Å to 5 μm.
Claim 6
Dependent Claim
29 words
An organic electroluminescent device according to claim 4 further characterized in that said capping layer has a thickness in the range of from about 2000 Å to 2 μm.
Claim 7
Dependent Claim
52 words
An organic electroluminescent device according to claim 1 further characterized in that said electron injecting layer contains a rare earth having a work function in the range of from 3.0 to 3.5 eV and said capping layer contains an alkaline earth or rare earth having a work function of less than 3.0.
Claim 8
Dependent Claim
41 words
An organic electroluminescent device according to claim 1 further characterized in that said electron injecting layer contains as its lowest work function metal a metal having its work function in the range range of from 3.5 to less than 4.0 eV.
Claim 9
Dependent Claim
24 words
An organic electroluminescent device according to claim 7 further characterized in that said electron injecting layer contains magnesium as its lowest work function metal.
Claim 10
Dependent Claim
27 words
An organic electroluminescent device according to claim 8 further characterized in that said electron injecting layer additionally contains a metal having a higher work function than magnesium.
Claim 11
Dependent Claim
29 words
An organic electroluminescent device according to claim 8 further characterized in that said capping layer contains an alkaline earth metal other than magnesium as its lowest work function metal.
Claim 12
Dependent Claim
20 words
An organic electroluminescent device according to claim 8 further characterized in that said capping layer contains a rare earth metal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-21 | 1995-04-22 | 1995-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-21 | 1999-04-22 | 1999-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-21 | 2003-04-22 | 2003-10-22 | $7700.00 | Window Closed / Lapsed |