Patent US5798170A successfully refreshed from Google Patents.
US5798170A
Expired / Lapsed
US
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Long operating life for polymer light-emitting diodes
Assignee: DuPont Displays Inc
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Filing: 1996-02-29
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Granted: 1998-08-25
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Expires: 2016-02-29
Abstract
Abstract Long-lived organic light-emitting diodes are achieved by positioning a layer comprising polyaniline in the emeraldine salt form directly contiguous with the anode side of the active light-emitting layer. Particular advantages are achieved if the emeraldine salt-containing layer has a sheet resistance of at least about 103 ohms per square which can be achieved by casting the layer from solution in a polar solvent, most particularly, DMSO. The LED's can find advantageous application in displays where they exhibit long life and marked resistance to blurring, spreading or other degradations over time.
Inventors
- 👤 Chi Zhang
- 👤 Gang Yu
- 👤 Yong Cao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:13
CPC Classifications
H; H10; H10K; H10K85/00; H10K85/10; H10K85/111; H10K50/00; H10K50/10; H10K50/17; H10K50/171; H10K59/00; H10K59/10; H10K59/17; H10K59/179; H10K59/1795; Y; Y10; Y10S; Y10S428/00; Y10S428/917; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/24942; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
58 words
An organic light-emitting diode having an operating lifetime in excess of 1000 hours comprising a semitransparent anode having a sheet resistance of less than 10 3 ohms per square separated from an organic light-emitting layer by an intermediate layer comprising polyaniline emeraldine salt said intermediate layer having a sheet resistance of more than 10 3 ohms per square.
Claim 2
Dependent Claim
58 words
An organic light-emitting diode having an operating lifetime in excess of 1000 hours comprising a semitransparent anode having a sheet resistance of less than 10 3 ohms per square separated from an organic light-emitting layer by an intermediate layer comprising polyaniline emeraldine salt said intermediate layer having a sheet resistance of more than 10 3 ohms per square.
Claim 3
Dependent Claim
23 words
The organic light-emitting diode of claim 1 wherein the semitransparent anode has a sheet resistance of less than 10 2 ohms per square.
Claim 4
Dependent Claim
17 words
The organic light-emitting diode of claim 1 wherein the intermediate layer consists essentially of polyaniline emeraldine salt.
Claim 5
Dependent Claim
21 words
The organic light-emitting diode of claim 1 wherein the intermediate layer comprises a blend of polyaniline emeraldine salt and host polymer.
Claim 6
Dependent Claim
63 words
An organic light-emitting diode having an operating lifetime in excess of 1000 hours comprising in layer order a semitransparent anode layer having a sheet resistance of less than 10 3 ohms per square an intermediate layer comprising polyaniline emeraldine salt said intermediate layer having a sheet resistance of more than 10 3 ohms per square an organic light-emitting layer and a cathode layer.
Claim 7
Dependent Claim
63 words
An organic light-emitting diode having an operating lifetime in excess of 1000 hours comprising in layer order a semitransparent anode layer having a sheet resistance of less than 10 3 ohms per square an intermediate layer comprising polyaniline emeraldine salt said intermediate layer having a sheet resistance of more than 10 3 ohms per square an organic light-emitting layer and a cathode layer.
Claim 8
Dependent Claim
17 words
The organic light-emitting diode of claim 5 additionally comprising a transparent support which carries the anode layer.
Claim 9
Dependent Claim
23 words
The organic light-emitting diode of claim 5 wherein the semitransparent anode has a sheet resistance of less than 10 2 ohms per square.
Claim 10
Dependent Claim
23 words
The organic light-emitting diode of claim 5 wherein the intermediate layer has a sheet resistance of greater than 10 4 ohms per square.
Claim 11
Dependent Claim
17 words
The organic light-emitting diode of claim 8 wherein the intermediate layer consists essentially of polyaniline emeraldine salt.
Claim 12
Dependent Claim
21 words
The organic light-emitting diode of claim 8 wherein the intermediate layer comprises a blend of polyaniline emeraldine salt and host polymer.
Claim 13
Dependent Claim
48 words
A method for producing usable levels of light over a prolonged period of time comprising applying a turn on voltage exceeding voltage across the device of claim 5 thereby giving rise to light emission from the device and using the light so emitted for at least 1000 hours.
Claim 14
Dependent Claim
25 words
A display having an operating lifetime in excess of 1000 hours comprising the light emitting diode of claim 5 wherein the anode layer is patterned.
Claim 15
Independent Claim
132 words
A method for forming an organic light-emitting diode having an operating lifetime in excess of 1000 hours, said diode having in layer order a semitransparent anode layer having a sheet resistance of less than 10 3 ohms per square an intermediate layer comprising polyaniline emeraldine salt said intermediate layer having a sheet resistance of more than 10 3 ohms per square an organic light-emitting layer and a cathode layer, comprising depositing the intermediate layer upon the anode layer from solution comprising emeraldine salt in a liquid selected from the group consisting of DMSO, tetramethylsulfoxide, 4-butylactone, propylene carbonate, chloroform, chlorobenzene, dichloromethane, benzyl alcohol, trifluoroethanol, octafluoropentanol, formic acid, acetic acid, trichloroacetic acid and mixtures thereof, depositing the organic light-emitting layer upon the intermediate layer and depositing the cathode layer upon the light emitting layer.
Claim 16
Independent Claim
132 words
A method for forming an organic light-emitting diode having an operating lifetime in excess of 1000 hours, said diode having in layer order a semitransparent anode layer having a sheet resistance of less than 10 3 ohms per square an intermediate layer comprising polyaniline emeraldine salt said intermediate layer having a sheet resistance of more than 10 3 ohms per square an organic light-emitting layer and a cathode layer, comprising depositing the intermediate layer upon the anode layer from solution comprising emeraldine salt in a liquid selected from the group consisting of DMSO, tetramethylsulfoxide, 4-butylactone, propylene carbonate, chloroform, chlorobenzene, dichloromethane, benzyl alcohol, trifluoroethanol, octafluoropentanol, formic acid, acetic acid, trichloroacetic acid and mixtures thereof, depositing the organic light-emitting layer upon the intermediate layer and depositing the cathode layer upon the light emitting layer.
Claim 17
Dependent Claim
10 words
The method of claim 13 wherein the liquid comprises DMSO.
Claim 18
Dependent Claim
12 words
The method of claim 14 wherein the solution additionally comprises host polymer.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 2001-08-24 | 2002-02-23 | 2002-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-24 | 2006-02-23 | 2006-08-25 | $3760.00 | Window Closed / Lapsed |
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