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US5537000A Expired / Lapsed US ⏱️ 0.0 years remaining

Electroluminescent devices formed using semiconductor nanocrystals as an electron transport media and method of making such electroluminescent devices

Assignee: University of California
•
Filing: 1994-04-29
•
Granted: 1996-07-16
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Expires: 2014-04-29
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Abstract

Abstract An electroluminescent device is described, as well as a method of making same, wherein the device is characterized by a semiconductor nanocrystal electron transport layer capable of emitting visible light in response to a voltage applied to the device. The wavelength of the light emitted by the device may be changed by changing either the size or the type of semiconductor nanocrystals used in forming the electron transport layer. In a preferred embodiment the device is further characterized by the capability of emitting visible light of varying wavelengths in response to changes in the voltage applied to the device. The device comprises a hole processing structure capable of injecting and transporting holes, and usually comprising a hole injecting layer and a hole transporting layer; an electron transport layer in contact with the hole processing structure and comprising one or more layers of semiconductor nanocrystals; and an electron injecting layer in contact with the electron transport layer for injecting electrons into the electron transport layer. The capability of emitting visible light of various wavelengths is principally based on the variations in voltage applied thereto, but the type of semiconductor nanocrystals used and the size of the semiconductor nanocrystals in the layers of semiconductor nanometer crystals may also play a role in color change, in combination with the change in voltage.

Inventors

  • 👤 A. Paul Alivisatos
  • 👤 Vickie Colvin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 05:03
CPC Classifications
B; B82; B82Y; B82Y30/00; B82Y20/00; H; H05; H05B; H05B33/00; H05B33/10; H05B33/12; H05B33/14; H10; H10K; H10K50/00; H10K50/10; H10K50/11; H10K50/125

Claims Analysis

Total Claims: 59
Claim 1
Independent Claim 63 words
An electroluminescent device comprising: a) hole processing means capable of injecting and transporting holes; b) electron transport means in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals having an average cross-section no larger than about 20 nm.; and c) electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 2
Dependent Claim 63 words
An electroluminescent device comprising: a) hole processing means capable of injecting and transporting holes; b) electron transport means in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals having an average cross-section no larger than about 20 nm.; and c) electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 3
Dependent Claim 24 words
The electroluminescent device of claim 1 wherein said semiconductor nanocrystals comprise single crystal particles having an average cross-section no larger than about 10 nm.
Claim 4
Dependent Claim 29 words
The electroluminescent device of claim 1 wherein said semiconductor nanocrystals comprise single crystal particles having an average cross-section ranging in size from about 1 nm to about 10 nm.
Claim 5
Dependent Claim 14 words
The electroluminescent device of claim 1 wherein said semiconductor nanocrystals comprise group II-VI semiconductors.
Claim 6
Dependent Claim 14 words
The electroluminescent device of claim 1 wherein said semiconductor nanocrystals comprise group III-V semiconductors.
Claim 7
Dependent Claim 20 words
The electroluminescent device of claim 1 wherein said electron transport means comprises a plurality of layers of said semiconductor nanocrystals.
Claim 8
Dependent Claim 16 words
The electroluminescent device of claim 1 wherein said hole processing means are transparent to visible light.
Claim 9
Dependent Claim 31 words
The electroluminescent device of claim 7 wherein said hole processing means comprise a hole injection layer and a hole transport layer between said hole injection layer and said electron transport layer.
Claim 10
Dependent Claim 38 words
The electroluminescent device of claim 1 wherein said electron transport means comprises one or more monolayers of one size of said semiconductor nanocrystals and one or more monolayers of at least one other size of said semiconductor nanocrystals.
Claim 11
Dependent Claim 31 words
The electroluminescent device of claim 1 wherein said electron transport means comprises one or more monolayers of semiconductor nanocrystals containing a mixture of two or more sizes of said semiconductor nanocrystals.
Claim 12
Dependent Claim 38 words
The electroluminescent device of claim 1 wherein said electron transport means comprises one or more monolayers of one type of said semiconductor nanocrystals and one or more monolayers of at least one other type of said semiconductor nanocrystals.
Claim 13
Dependent Claim 31 words
The electroluminescent device of claim 1 wherein said electron transport means comprises one or more monolayers of semiconductor nanocrystals containing a mixture of two or more types of said semiconductor nanocrystals.
Claim 14
Dependent Claim 16 words
The electroluminescent device of claim 1 wherein said electron injection means are transparent to visible light.
Claim 15
Dependent Claim 56 words
The electroluminescent device of claim 1 wherein said hole processing means comprise one or more layers not transparent to visible light and said electron injection means comprise a layer not transparent to visible light, and light emitted by said device is viewed from an end edge of said non-transparent layers comprising a side of said device.
Claim 16
Dependent Claim 91 words
An electroluminescent device capable of emitting visible light of a particular wavelength upon application of a voltage thereto, which comprises: a) hole processing means capable of injecting and transporting holes; b) an electron transport layer in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals capable of emitting visible light of a particular wavelength and having an average cross-section no larger than about 20 nm.; and c) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer.
Claim 17
Dependent Claim 91 words
An electroluminescent device capable of emitting visible light of a particular wavelength upon application of a voltage thereto, which comprises: a) hole processing means capable of injecting and transporting holes; b) an electron transport layer in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals capable of emitting visible light of a particular wavelength and having an average cross-section no larger than about 20 nm.; and c) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer.
Claim 18
Dependent Claim 40 words
The electroluminescent device of claim 15 wherein either said hole processing means or said electron injecting layer is transparent to said visible light emitted by said semiconductor nanocrystal electron transport layer therebetween to thereby permit viewing of said emitted light.
Claim 19
Dependent Claim 104 words
An electroluminescent device characterized by the capability of emitting visible light of varying wavelengths based on variations in voltage applied thereto and comprising: a) a hole injection layer; b) a hole transport layer in contact with said hole injecting layer for transporting therethrough said holes injected therein; c) an electron transport layer in contact with said hole transport layer comprising one or more layers of semiconductor nanocrystals comprising single crystal semiconductor material having a particle size of not more than about 10 nm.; and c) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer.
Claim 20
Dependent Claim 104 words
An electroluminescent device characterized by the capability of emitting visible light of varying wavelengths based on variations in voltage applied thereto and comprising: a) a hole injection layer; b) a hole transport layer in contact with said hole injecting layer for transporting therethrough said holes injected therein; c) an electron transport layer in contact with said hole transport layer comprising one or more layers of semiconductor nanocrystals comprising single crystal semiconductor material having a particle size of not more than about 10 nm.; and c) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer.
Claim 21
Dependent Claim 24 words
The electroluminescent device of claim 17 wherein said semiconductor nanocrystals have a particle size range of from about 1 nm. to about 10 nm.
Claim 22
Dependent Claim 24 words
The electroluminescent device of claim 17 wherein said semiconductor nanocrystals are selected from the group consisting of group II-VI semiconductors and group III-V semiconductors.
Claim 23
Dependent Claim 25 words
The electroluminescent device of claim 17 wherein said hole injection layer, said hole transport layer, and said electron transport layer are transparent to visible light.
Claim 24
Dependent Claim 24 words
The electroluminescent device of claim 17 wherein said hole injection layer comprises a conductive layer capable of injecting holes into said hole transport layer.
Claim 25
Dependent Claim 26 words
The electroluminescent device of claim 17 wherein said hole transport layer comprises a polymeric layer capable of transporting holes injected therein by said hole injection layer.
Claim 26
Dependent Claim 29 words
The electroluminescent device of claim 17 wherein said electron injection layer comprises a metal layer capable of injecting electrons into said electron transport layer comprising said semiconductor nanometer crystals.
Claim 27
Dependent Claim 16 words
The electroluminescent device of claim 17 wherein said electron injection layer is transparent to visible light.
Claim 28
Dependent Claim 151 words
An electroluminescent device characterized by the capability of emitting visible light of varying wavelengths based on variations in voltage applied thereto and comprising: a) a hole injection layer, comprising a conductive layer capable of injecting holes into said device; b) a hole transport layer in contact with said hole injecting layer for transporting therethrough said holes injected therein; c) an electron transport layer in contact with said hole transport layer comprising one or more layers of semiconductor nanocrystals selected from the group consisting of group II-VI semiconductors and group III-V semiconductors, and comprising single crystal semiconductor material having a particle size of not more than about 10 nm.; and c) an electron injecting layer in contact with said electron transport layer and comprising a metal layer capable of injecting electrons into said electron transport layer comprising said semiconductor nanocrystals; wherein at least one of said layers is transparent to visible light.
Claim 29
Dependent Claim 151 words
An electroluminescent device characterized by the capability of emitting visible light of varying wavelengths based on variations in voltage applied thereto and comprising: a) a hole injection layer, comprising a conductive layer capable of injecting holes into said device; b) a hole transport layer in contact with said hole injecting layer for transporting therethrough said holes injected therein; c) an electron transport layer in contact with said hole transport layer comprising one or more layers of semiconductor nanocrystals selected from the group consisting of group II-VI semiconductors and group III-V semiconductors, and comprising single crystal semiconductor material having a particle size of not more than about 10 nm.; and c) an electron injecting layer in contact with said electron transport layer and comprising a metal layer capable of injecting electrons into said electron transport layer comprising said semiconductor nanocrystals; wherein at least one of said layers is transparent to visible light.
Claim 30
Dependent Claim 25 words
The electroluminescent device of claim 25 wherein said hole injection layer, said hole transport layer, and said electron transport layer are transparent to visible light.
Claim 31
Dependent Claim 16 words
The electroluminescent device of claim 25 wherein said electron injection layer is transparent to visible light.
Claim 32
Dependent Claim 39 words
The electroluminescent device of claim 25 wherein said hole injection layer comprise a conductive layer selected from the group consisting of indium tin oxide, gold, zinc oxide and a p-type semiconductor with a band gap greater than 3 eV.
Claim 33
Dependent Claim 26 words
The electroluminescent device of claim 25 wherein said hole transport layer comprise a polymeric layer capable of transporting holes injected therein by said hole injection means.
Claim 34
Dependent Claim 28 words
The electroluminescent device of claim 25 wherein said electron injection layer comprise a metal layer selected from the group consisting of magnesium, calcium, strontium, barium, indium, and aluminum.
Claim 35
Dependent Claim 56 words
The electroluminescent device of claim 25 wherein said electron transport layer comprises semiconductor nanocrystals selected from the group consisting of MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe; HgS, HgSe, HgTe, GaSh, InAs, InP, and InSb; and mixtures of two or more of said semiconductor compounds.
Claim 36
Dependent Claim 44 words
The electroluminescent device of claim 25 wherein said electron transport layer comprises semiconductor nanocrystals selected from the group consisting of ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe; HgS, HgSe, HgTe, GaSh, InAs, InP, and InSb: and mixtures of two or more of said semiconductor compounds.
Claim 37
Independent Claim 75 words
A method of making an electroluminescent device comprising: a) forming hole processing means capable of injecting and transporting holes; b) forming electron transport means in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals capable of emitting light and having an average cross-section no larger than about 20 nm.; and c) forming electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 38
Independent Claim 75 words
A method of making an electroluminescent device comprising: a) forming hole processing means capable of injecting and transporting holes; b) forming electron transport means in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals capable of emitting light and having an average cross-section no larger than about 20 nm.; and c) forming electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 39
Dependent Claim 180 words
A flat-panel display for providing an image utilizing emitted light from a plurality of electroluminescent devices, said display comprising: a) a plurality of electroluminescent devices arranged in an array, each of said electroluminescent devices comprising: i) hole processing means capable of injecting and transporting holes; ii) an electron transport layer in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals having an average cross-section no larger than about 20 nm.; and iii) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer; b) a first electronic control input unit capable of receiving one or more input signals and operably coupled to said array of electroluminescent devices; and c) a second electronic control input unit also capable of receiving one or more input signals and also operably coupled to said array of electroluminescent devices; whereby said first and second electronic control input units are arranged to provide voltages across preselected portions of said array of electroluminescent devices, in response to said input signals, to provide said image.
Claim 40
Dependent Claim 180 words
A flat-panel display for providing an image utilizing emitted light from a plurality of electroluminescent devices, said display comprising: a) a plurality of electroluminescent devices arranged in an array, each of said electroluminescent devices comprising: i) hole processing means capable of injecting and transporting holes; ii) an electron transport layer in contact with said hole processing means comprising one or more monolayers of semiconductor nanocrystals having an average cross-section no larger than about 20 nm.; and iii) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer; b) a first electronic control input unit capable of receiving one or more input signals and operably coupled to said array of electroluminescent devices; and c) a second electronic control input unit also capable of receiving one or more input signals and also operably coupled to said array of electroluminescent devices; whereby said first and second electronic control input units are arranged to provide voltages across preselected portions of said array of electroluminescent devices, in response to said input signals, to provide said image.
Claim 41
Dependent Claim 68 words
The flat-panel display device of claim 34 wherein said first and second electronic control input units each comprise a plane of parallel electrodes, said parallel electrodes of said first electronic control input unit being perpendicular to said parallel electrodes of said second control input unit, and said array of electroluminescent devices is located between said respective planes of parallel electrodes of said first and second control input units.
Claim 42
Dependent Claim 45 words
The flat-panel display device of claim 35 wherein at least one of said first and second electronic control input units receives an active matrix drive signal addressing data to drive at least a portion (240 rows by 640 columns) of a video graphics array (VGA).
Claim 43
Dependent Claim 30 words
The flat-panel display device of claim 34 wherein said semiconductor nanocrystals comprise single crystal particles having an average cross-section ranging in size from about 1 nm. to about 20 nm.
Claim 44
Dependent Claim 30 words
The flat-panel display device of claim 34 wherein said semiconductor nanocrystals comprise single crystal particles having an average cross-section ranging in size from about 1 nm. to about 10 nm.
Claim 45
Dependent Claim 15 words
The flat-panel display device of claim 38 wherein said semiconductor nanocrystals comprise group II-VI semiconductors.
Claim 46
Dependent Claim 15 words
The flat-panel display device of claim 38 wherein said semiconductor nanocrystals comprise group III-V semiconductors.
Claim 47
Dependent Claim 21 words
The flat-panel display device of claim 38 wherein said electron transport layer comprises a plurality of layers of said semiconductor nanocrystals.
Claim 48
Dependent Claim 17 words
The flat-panel display device of claim 38 wherein said hole processing means are transparent to visible light.
Claim 49
Dependent Claim 32 words
The flat-panel display device of claim 42 wherein said hole processing means comprise a hole injection layer, and a hole transport layer between said hole injection layer and said electron transport layer.
Claim 50
Dependent Claim 39 words
The flat-panel display device of claim 38 wherein said electron transport layer comprises one or more monolayers of one size of said semiconductor nanocrystals and one or more monolayers of at least one other size of said semiconductor nanocrystals.
Claim 51
Dependent Claim 32 words
The flat-panel display device of claim 38 wherein said electron transport layer comprises one or more monolayers of semiconductor nanocrystals containing a mixture of two or more types of said semiconductor nanocrystals.
Claim 52
Dependent Claim 39 words
The flat-panel display device of claim 38 wherein said electron transport layer comprises one or more monolayers of one type of said semiconductor nanocrystals and one or more monolayers of at least one other type of said semiconductor nanocrystals.
Claim 53
Dependent Claim 17 words
The flat-panel display device of claim 38 wherein said electron injection layer is transparent to visible light.
Claim 54
Dependent Claim 54 words
An electroluminescent device comprising: a) hole processing means capable of injecting and transporting holes; b) electron transport means in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals; and c) electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 55
Dependent Claim 54 words
An electroluminescent device comprising: a) hole processing means capable of injecting and transporting holes; b) electron transport means in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals; and c) electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 56
Independent Claim 65 words
A method of making an electroluminescent device comprising: a) forming hole processing means capable of injecting and transporting holes; b) forming electron transport means in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals capable of emitting light; and c) forming electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 57
Independent Claim 65 words
A method of making an electroluminescent device comprising: a) forming hole processing means capable of injecting and transporting holes; b) forming electron transport means in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals capable of emitting light; and c) forming electron injecting means in contact with said electron transport means for injecting electrons into said electron transport means.
Claim 58
Dependent Claim 171 words
A flat-panel display for providing an image utilizing emitted light from a plurality of electroluminescent devices, said display comprising: a) a plurality of electroluminescent devices arranged in an array, each of said electroluminescent devices comprising: i) hole processing means capable of injecting and transporting holes; ii) an electron transport layer in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals; and iii) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer; b) a first electronic control input unit capable of receiving one or more input signals and operably coupled to said array of electroluminescent devices; and c) a second electronic control input unit also capable of receiving one or more input signals and also operably coupled to said array of electroluminescent devices; whereby said first and second electronic control input units are arranged to provide voltages across preselected portions of said array of electroluminescent devices, in response to said input signals, to provide said image.
Claim 59
Dependent Claim 171 words
A flat-panel display for providing an image utilizing emitted light from a plurality of electroluminescent devices, said display comprising: a) a plurality of electroluminescent devices arranged in an array, each of said electroluminescent devices comprising: i) hole processing means capable of injecting and transporting holes; ii) an electron transport layer in contact with said hole processing means comprising one or more monolayers of inorganic semiconductor nanocrystals; and iii) an electron injecting layer in contact with said electron transport layer for injecting electrons into said electron transport layer; b) a first electronic control input unit capable of receiving one or more input signals and operably coupled to said array of electroluminescent devices; and c) a second electronic control input unit also capable of receiving one or more input signals and also operably coupled to said array of electroluminescent devices; whereby said first and second electronic control input units are arranged to provide voltages across preselected portions of said array of electroluminescent devices, in response to said input signals, to provide said image.

References Cited (Backward Citations)

US4814668A Cited
US5200668A Cited

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