US5821690A
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Electroluminescent devices having a light-emitting layer
Assignee: Cambridge Display Technology Ltd
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Filing: 1994-08-23
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Granted: 1998-10-13
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Expires: 2014-08-23
Abstract
Abstract An electroluminescent device includes first and second layers (6, 12) of light emitting semiconductive conjugated polymers with an electrode arrangement (4, 8, 10, 14) for injecting charge carriers into both light emissive layers to cause light to be emitted therefrom. The first and second light emitting layers are in viewing overlap, and the electrode arrangement includes two sets of electrodes (4, 8, 10, 12) which can be operated independently. The first light emissive layer is arranged to emit radiation of a first wavelength when excited and the second light emissive layer is arranged to emit radiation of a second wavelength when excited. The electroluminescent device can thus be operated to cause either radiation of the first wavelength or radiation of the second wavelength or both to be emitted and viewed.
Inventors
- 👤 Josef Herbert Ferdinand Martens
- 👤 Paul Leslie Burn
- 👤 Karl Pichler
- 👤 Richard Henry Friend
- 👤 Andrew Bruce Holmes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:15
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/06; H; H05; H05B; H05B33/00; H05B33/10; H05B33/12; H05B33/14; H05B33/26; H10; H10K; H10K50/00; H10K50/10; H10K50/11; H10K50/125; H10K50/80; H10K50/805; H10K59/00; H10K59/30; H10K59/32; H10K59/80; H10K59/86; H10K85/00; H10K85/10; H10K85/111; H10K85/114
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
185 words
An electroluminescent device comprising: a first emitter comprising an organic layer selected so that radiation of a first wavelength is emitted when charge carriers of opposite types are injected into the first emitter; first electrode means arranged to inject charge carriers into said first emitter, said first electrode means including first and second contact layers of different types arranged on either side of the first emitter and connected to a source for applying an electric field between the first and second contact layers so that charge carriers of respective first and second types are injected into the first emitter; a second emitter comprising an organic layer arranged in viewing overlap with said first emitter and selected so that radiation of a second wavelength is emitted when charge carriers of opposite types are injected into the second emitter; and second electrode means arranged to inject charge carriers into said second emitter, said second electrode means being operable independently of said first electrode means whereby either radiation of said first wavelength or radiation of said second wavelength or both can be caused to be emitted and viewed.
Claim 2
Dependent Claim
185 words
An electroluminescent device comprising: a first emitter comprising an organic layer selected so that radiation of a first wavelength is emitted when charge carriers of opposite types are injected into the first emitter; first electrode means arranged to inject charge carriers into said first emitter, said first electrode means including first and second contact layers of different types arranged on either side of the first emitter and connected to a source for applying an electric field between the first and second contact layers so that charge carriers of respective first and second types are injected into the first emitter; a second emitter comprising an organic layer arranged in viewing overlap with said first emitter and selected so that radiation of a second wavelength is emitted when charge carriers of opposite types are injected into the second emitter; and second electrode means arranged to inject charge carriers into said second emitter, said second electrode means being operable independently of said first electrode means whereby either radiation of said first wavelength or radiation of said second wavelength or both can be caused to be emitted and viewed.
Claim 3
Dependent Claim
43 words
An electroluminescent device according to claim 1, wherein the second electrode means comprises third and fourth contact layers on either side of the second emitter and connected to a second source for applying an electric field between the third and fourth contact layers.
Claim 4
Dependent Claim
52 words
An electroluminescent device according to claim 1, wherein the second electrode means includes said second contact layer and a third contact layer lying on the other side of the second emitter, said second and third contact layers being connected to a second source for applying an electric field across the second emitter.
Claim 5
Dependent Claim
23 words
An electroluminescent device according to claim 1, wherein the first contact layer comprises indium tin oxide and the second contact layer comprises calcium.
Claim 6
Dependent Claim
21 words
An electroluminescent device according to claim 2 wherein the third contact layer comprises gold and the fourth contact layer comprises calcium.
Claim 7
Dependent Claim
20 words
An electroluminescent device according to claim 5 wherein the fourth contact layer of calcium is provided with a capping layer.
Claim 8
Dependent Claim
13 words
An electroluminescent device according to claim 6 wherein the capping layer comprises aluminium.
Claim 9
Dependent Claim
21 words
An electroluminescent device according to claim 4 wherein the third contact layer comprises gold and the fourth contact layer comprises calcium.
Claim 10
Dependent Claim
20 words
An electroluminescent device according to claim 8 wherein the fourth contact layer of calcium is provided with a capping layer.
Claim 11
Dependent Claim
13 words
An electroluminescent device according to claim 9 wherein the capping layer comprises aluminium.
Claim 12
Dependent Claim
27 words
An electroluminescent device according to claim 2 wherein the combined thickness of the second and third contact layers is of the order of a few hundred angstroms.
Claim 13
Dependent Claim
27 words
An electroluminescent device according to claim 5 wherein the combined thickness of the second and third contact layers is of the order of a few hundred angstroms.
Claim 14
Dependent Claim
27 words
An electroluminescent device according to claim 1 wherein at least one of the first emitter and the second emitter comprise at least one sublimed organic molecular layer.
Claim 15
Dependent Claim
26 words
An electroluminescent device according claim 1 wherein at least one of the first emitter and the second emitter comprise at least one semiconductive conjugated polymer layer.
Claim 16
Dependent Claim
28 words
An electroluminescent device according to claim 1 wherein at least one of the first emitter and the second emitter each comprise a plurality of semiconductive conjugated polymer layers.
Claim 17
Dependent Claim
16 words
An electroluminescent device according to claim 1 wherein the first emitter comprises a layer of PPV.
Claim 18
Dependent Claim
16 words
An electroluminescent device according to claim 1 wherein the second emitter comprises a layer of MEH-PPV.
Claim 19
Dependent Claim
28 words
An electroluminescent device according to claim 14 wherein each layer of semiconductive conjugated polymer has a semiconductive bandgap selected so that radiation of a predetermined wavelength is emitted.
Claim 20
Dependent Claim
28 words
An electroluminescent device according to claim 15 wherein each layer of semiconductive conjugated polymer has a semiconductive bandgap selected so that radiation of a predetermined wavelength is emitted.
Claim 21
Dependent Claim
28 words
An electroluminescent device according to claim 16 wherein each layer of semiconductive conjugated polymer has a semiconductive bandgap selected so that radiation of a predetermined wavelength is emitted.
Claim 22
Dependent Claim
28 words
An electroluminescent device according to claim 17 wherein each layer of semiconductive conjugated polymer has a semiconductive bandgap selected so that radiation of a predetermined wavelength is emitted.
Claim 23
Independent Claim
243 words
A method of making an electroluminescent device comprising the steps of: providing on a substrate a first electrode for injecting charge carriers of a first type; depositing on top of said first electrode a first emitter comprising an organic layer selected so that radiation of a first wavelength is emitted when charge carriers of opposite types are injected into the first emitter; providing on top of said first emitter a second electrode for injecting charge carriers of a second type; depositing on top of said second electrode a second emitter comprising an organic layer selected so that radiation of a second wavelength is emitted when charge carriers of opposite types are injected into the second emitter; providing on top of said second emitter a third electrode for injecting charge carriers of said first type; connecting the first and second electrodes to a first source for applying an electric field across the first emitter so that charge carriers of the first and second types are injected into the first emitter; and connecting the second and third electrodes to a second source for applying an electric field across the second emitter so that charge carriers of the first and second types are injected into the second emitter, the first and second source for applying electric fields being operable independently one from another whereby either radiation of said first wavelength or radiation of said second wavelength or both can be caused to be emitted and viewed.
Claim 24
Independent Claim
243 words
A method of making an electroluminescent device comprising the steps of: providing on a substrate a first electrode for injecting charge carriers of a first type; depositing on top of said first electrode a first emitter comprising an organic layer selected so that radiation of a first wavelength is emitted when charge carriers of opposite types are injected into the first emitter; providing on top of said first emitter a second electrode for injecting charge carriers of a second type; depositing on top of said second electrode a second emitter comprising an organic layer selected so that radiation of a second wavelength is emitted when charge carriers of opposite types are injected into the second emitter; providing on top of said second emitter a third electrode for injecting charge carriers of said first type; connecting the first and second electrodes to a first source for applying an electric field across the first emitter so that charge carriers of the first and second types are injected into the first emitter; and connecting the second and third electrodes to a second source for applying an electric field across the second emitter so that charge carriers of the first and second types are injected into the second emitter, the first and second source for applying electric fields being operable independently one from another whereby either radiation of said first wavelength or radiation of said second wavelength or both can be caused to be emitted and viewed.
Claim 25
Dependent Claim
37 words
A method according to claim 22 wherein the step of providing a first electrode comprises coating a glass substrate with indium tin oxide and etching the indium tin oxide to define an active area of the device.
Claim 26
Dependent Claim
41 words
A method according to claim 22 wherein the step of providing a second electrode comprises depositing a semi-transparent metallic layer having a thickness of the order of a few hundred angstroms in the form of a strip overlapping the first electrode.
Claim 27
Dependent Claim
32 words
A method according to claim 22 wherein the step of providing a third electrode comprises depositing a metallic layer in the form of a strip in partial overlap with the second electrode.
Claim 28
Dependent Claim
26 words
A method according to claim 22 wherein at least one of the first emitter and the second emitter comprise a layer of a semiconductive conjugated polymer.
Claim 29
Dependent Claim
26 words
A method according to claim 22 wherein at least one of the first emitter and the second emitter comprise a layer of sublimed organic molecular film.
Claim 30
Dependent Claim
205 words
An electroluminescent device comprising: a first emitter comprising an organic layer selected so that radiation of a first wavelength is emitted when charge carriers of opposite types are injected into the first emitter; first electrode means arranged to inject charge carriers into said first emitter, said first electrode means including first and second contact layers of different types arranged on either side of the first emitter and connected to a source for applying an electric field between the first and second contact layers so that charge carriers of respective first and second types are injected into the first emitter, the second contract layer comprising a semi-transparent metallic layer having a thickness of the order of a few hundred angstroms; a second emitter comprising an organic layer arranged in viewing overlap with said first emitter and selected so that radiation of a second wavelength is emitted when charge carriers of opposite types are injected into the second emitter; and second electrode means arranged to inject charge carriers into said second emitter, said second electrode means being operable independently of said first electrode means whereby either radiation of said first wavelength or radiation of said second wavelength or both can be caused to be emitted and viewed.
Claim 31
Dependent Claim
205 words
An electroluminescent device comprising: a first emitter comprising an organic layer selected so that radiation of a first wavelength is emitted when charge carriers of opposite types are injected into the first emitter; first electrode means arranged to inject charge carriers into said first emitter, said first electrode means including first and second contact layers of different types arranged on either side of the first emitter and connected to a source for applying an electric field between the first and second contact layers so that charge carriers of respective first and second types are injected into the first emitter, the second contract layer comprising a semi-transparent metallic layer having a thickness of the order of a few hundred angstroms; a second emitter comprising an organic layer arranged in viewing overlap with said first emitter and selected so that radiation of a second wavelength is emitted when charge carriers of opposite types are injected into the second emitter; and second electrode means arranged to inject charge carriers into said second emitter, said second electrode means being operable independently of said first electrode means whereby either radiation of said first wavelength or radiation of said second wavelength or both can be caused to be emitted and viewed.
References Cited (Backward Citations)
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| 7.5 Years (Year 8) | 2005-10-12 | 2006-04-13 | 2006-10-13 | $3760.00 | Window Closed / Lapsed |
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