EP0468439A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Organic electroluminescent device with stabilizing cathode capping layer
Assignee: Eastman Kodak Co
•
Filing: 1991-07-23
•
Granted: —
•
Expires: 2011-07-23
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 Eric C/O Eastman Kodak Company Littman
- 👤 Michael C/O Eastman Kodak Company Scozzafava
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 18:33
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
95 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 or rare earth metal 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
95 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 or rare earth metal 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
22 words
An organic electroluminescent device according to claim 1 further characterized in that said capping layer has a thickness of at least 500A.
Claim 4
Dependent Claim
23 words
An organic electroluminescent device according to claim 2 further charactrerized in that said capping layer has a thickness of up to 10 µm.
Claim 5
Dependent Claim
28 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 1000A 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 2000A to 2 /1 .m.
Claim 7
Dependent Claim
39 words
An organic electroluminescent device according to any one of claims 1 to 5 inclusive further characterized in that capping layer contains at least one alkaline earth or rare earth metal having a work function of less than 3.5 eV.
Claim 8
Dependent Claim
58 words
An organic electroluminescent device according to any one of claims 1 to 6 inclusive 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 9
Dependent Claim
47 words
An organic electroluminescent device according to any one of claims 1 to 6 inclusive 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 10
Dependent Claim
24 words
An organic electroluminescent device according to claim 8 further characterized in that said electron injecting layer contains magnesium as its lowest work function metal.
Claim 11
Dependent Claim
27 words
An organic electroluminescent device according to claim 9 further characterized in that said electron injecting layer additionally contains a metal having a higher work function than magnesium.
Claim 12
Dependent Claim
31 words
An organic electroluminescent device according to claim 9 or 10 further characterized in that said capping layer contains an alkaline earth metal other than magnesium as its lowest work function metal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.