US5729094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Energetic-electron emitters
Assignee: Massachusetts Institute of Technology
•
Filing: 1996-04-15
•
Granted: 1998-03-17
•
Expires: 2016-04-15
Abstract
Abstract An energetic-electron emitter providing electrons having kinetic energies on the order of one thousand electron volts without acceleration through vacuum. An average electric field of 10 5 V/m to 10 10 V/m applied across a layer of emissive cathode material accelerates electrons inside the layer. The cathode material is a high-dielectric strength, rigid-structure, wide-bandgap semiconductors, especially type Ib diamond. A light-emitting device incorporates the energetic-electron emitter as a source of excitation to luminescence.
Inventors
- 👤 Michael W. Geis
- 👤 Jonathan C. Twichell
- 👤 Theodore M. Lyszczarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:10
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J1/304
Claims Analysis
Total Claims: 116
Claim 1
Independent Claim
96 words
An electron-emissive device comprising: a. a cathode body of diamond, the body having a surface with first and second locations separated by a thickness; b. first and second conductive materials disposed respectively on the first and second locations; and c. a voltage source, electrically connected to the cathode body by means of the first and second conductive materials so as to impose a body electric field having a body average amplitude greater than 10 5 V/m across the thickness, the imposition of the body electric field causing the cathode body to emit electrons having kinetic energies.
Claim 2
Dependent Claim
96 words
An electron-emissive device comprising: a. a cathode body of diamond, the body having a surface with first and second locations separated by a thickness; b. first and second conductive materials disposed respectively on the first and second locations; and c. a voltage source, electrically connected to the cathode body by means of the first and second conductive materials so as to impose a body electric field having a body average amplitude greater than 10 5 V/m across the thickness, the imposition of the body electric field causing the cathode body to emit electrons having kinetic energies.
Claim 3
Dependent Claim
14 words
The device of claim 1 wherein the voltage source imposes a dc electric field.
Claim 4
Dependent Claim
13 words
The device of claim 1 wherein the thickness is at least 10 μm.
Claim 5
Dependent Claim
13 words
The device of claim 1 wherein the thickness is at least 100 μm.
Claim 6
Dependent Claim
15 words
The device of claim 1 wherein the thickness is on the order of 1 mm.
Claim 7
Dependent Claim
11 words
The device of claim 1 wherein the diamond contains substitutional nitrogen.
Claim 8
Dependent Claim
23 words
The device of claim 6 wherein the substitutional nitrogen is present at a concentration equal to at least 10 18 cm -3 .
Claim 9
Dependent Claim
12 words
The device of claim 1 wherein the diamond is type Ib diamond.
Claim 10
Dependent Claim
15 words
The device of claim 1 wherein the diamond is in the form of a film.
Claim 11
Dependent Claim
12 words
The device of claim 1 wherein the diamond is a single crystal.
Claim 12
Dependent Claim
42 words
The device of claim 1 wherein the first conductive material is disposed on the first location with an interface having a roughness characterized by a radius of curvature less than 15 nm between the cathode body surface and the first conductive material.
Claim 13
Dependent Claim
21 words
The device of claim 1 wherein the body average amplitude of the body electric field is greater than 10 6 V/m.
Claim 14
Dependent Claim
21 words
The device of claim 1 wherein the body average amplitude of the body electric field is greater than 10 7 V/m.
Claim 15
Dependent Claim
21 words
The device of claim 1 wherein the body average amplitude of the body electric field is greater than 10 8 V/m.
Claim 16
Dependent Claim
21 words
The device of claim 1 wherein upon emission from the cathode body, electrons have kinetic energies of at least 50 eV.
Claim 17
Dependent Claim
21 words
The device of claim 1 wherein upon emission from the cathode body, electrons have kinetic energies of at least 200 eV.
Claim 18
Dependent Claim
21 words
The device of claim 1 wherein upon emission from the cathode body, electrons have kinetic energies of at least 500 eV.
Claim 19
Dependent Claim
41 words
The device of claim 1 wherein upon emission from the cathode body, electrons have kinetic energies equal to at least 10% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 20
Dependent Claim
41 words
The device of claim 1 wherein upon emission from the cathode body, electrons have kinetic energies equal to at least 40% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 21
Dependent Claim
20 words
The device of claim 1 further comprising phosphor material arranged to receive emitted electrons, thereby being excited to emit light.
Claim 22
Dependent Claim
45 words
The device of claim 1 further comprising an anode opposing the cathode body across an expanse of vacuum and a second voltage source coupled to the anode so as to impose a vacuum electric field having a vacuum average amplitude across the expanse of vacuum.
Claim 23
Dependent Claim
30 words
The device of claim 21 wherein the vacuum average amplitude is smaller than the body average amplitude of the body electric field imposed across the thickness of the cathode body.
Claim 24
Dependent Claim
42 words
The device of claim 22 wherein the vacuum electric field accelerates emitted electrons toward the anode, thereby increasing their kinetic energies by an increment, the increment being less than four times the kinetic energies of electrons upon emission from the cathode body.
Claim 25
Dependent Claim
21 words
The device of claim 1 wherein the body average amplitude of the body electric field is greater than 10 9 V/m.
Claim 26
Dependent Claim
20 words
The device of claim 1 wherein the average field strength of the electric field is greater than 10 10 V/m.
Claim 27
Dependent Claim
12 words
The device of claim 1 wherein the second conductive material is carbonaceous.
Claim 28
Dependent Claim
22 words
The device of claim 1 wherein the emitted electrons leave the cathode body at one of the first and the second locations.
Claim 29
Dependent Claim
25 words
The device of claim 1 further comprising an emission-enhancing material disposed on the surface, the emitted electrons leaving the cathode body through the emission-enhancing material.
Claim 30
Dependent Claim
11 words
The device of claim 1 the second conductive material is graphite.
Claim 31
Dependent Claim
112 words
An electron-emissive device comprising: a. a cathode body of diamond, the body having a surface with first and second locations separated by a thickness; b. first and second conductive materials disposed respectively on the first and second locations; c. a phosphor material in intimate contact with the cathode body; and d. a voltage source, electrically connected to the cathode body by means of the first and second conductive materials so as to impose a body electric field having a body average amplitude greater than 10 5 V/m across the thickness, the imposition of the body electric field causing electrons having kinetic energies to leave the cathode body and enter the phosphor material.
Claim 32
Dependent Claim
112 words
An electron-emissive device comprising: a. a cathode body of diamond, the body having a surface with first and second locations separated by a thickness; b. first and second conductive materials disposed respectively on the first and second locations; c. a phosphor material in intimate contact with the cathode body; and d. a voltage source, electrically connected to the cathode body by means of the first and second conductive materials so as to impose a body electric field having a body average amplitude greater than 10 5 V/m across the thickness, the imposition of the body electric field causing electrons having kinetic energies to leave the cathode body and enter the phosphor material.
Claim 33
Dependent Claim
33 words
The device of claim 30 wherein the phosphor material is disposed on the second conductive material so that electrons enter the phosphor material directly from the first conductive material, without passing through vacuum.
Claim 34
Dependent Claim
103 words
An electron-emissive device comprising: a. a cathode body of diamond, the body having a thickness; b. an anode opposing the cathode body across an expanse of vacuum; and c. a voltage source, coupled to the cathode body and to the anode so as to impose a body electric field, having a body average amplitude greater than 10 5 V/m, across the thickness and a vacuum electric field, having a vacuum average amplitude smaller than the body average amplitude, across the expanse of vacuum, the imposition of the body electric field causing the cathode body to emit into the vacuum electrons having kinetic energies.
Claim 35
Dependent Claim
103 words
An electron-emissive device comprising: a. a cathode body of diamond, the body having a thickness; b. an anode opposing the cathode body across an expanse of vacuum; and c. a voltage source, coupled to the cathode body and to the anode so as to impose a body electric field, having a body average amplitude greater than 10 5 V/m, across the thickness and a vacuum electric field, having a vacuum average amplitude smaller than the body average amplitude, across the expanse of vacuum, the imposition of the body electric field causing the cathode body to emit into the vacuum electrons having kinetic energies.
Claim 36
Dependent Claim
14 words
The device of claim 32 wherein the voltage source imposes a dc electric field.
Claim 37
Dependent Claim
13 words
The device of claim 32 wherein the thickness is at least 10 μm.
Claim 38
Dependent Claim
13 words
The device of claim 32 wherein the thickness is at least 100 μm.
Claim 39
Dependent Claim
15 words
The device of claim 32 wherein the thickness is on the order of 1 mm.
Claim 40
Dependent Claim
11 words
The device of claim 32 wherein the diamond contains substitutional nitrogen.
Claim 41
Dependent Claim
23 words
The device of claim 37 wherein the substitutional nitrogen is present at a concentration equal to at least 10 18 cm -3 .
Claim 42
Dependent Claim
12 words
The device of claim 32 wherein the diamond is type Ib diamond.
Claim 43
Dependent Claim
15 words
The device of claim 32 wherein the diamond is in the form of a film.
Claim 44
Dependent Claim
12 words
The device of claim 32 wherein the diamond is a single crystal.
Claim 45
Dependent Claim
59 words
The device of claim 32 wherein the cathode body has a surface and further comprising a conductive material disposed on the surface with an interface having a roughness characterized by a radius of curvature less than 15 nm between the surface and the conductive material, the voltage source electrically contacting the cathode body by means of the conductive material.
Claim 46
Dependent Claim
21 words
The device of claim 32 wherein the body average amplitude of the body electric field is greater than 10 6 V/m.
Claim 47
Dependent Claim
21 words
The device of claim 32 wherein the body average amplitude of the body electric field is greater than 10 7 V/m.
Claim 48
Dependent Claim
21 words
The device of claim 32 wherein the body average amplitude of the body electric field is greater than 10 8 V/m.
Claim 49
Dependent Claim
21 words
The device of claim 32 wherein upon emission from the cathode body, electrons have kinetic energies of at least 50 eV.
Claim 50
Dependent Claim
21 words
The device of claim 32 wherein upon emission from the cathode body, electrons have kinetic energies of at least 200 eV.
Claim 51
Dependent Claim
21 words
The device of claim 32 wherein upon emission from the cathode body, electrons have kinetic energies of at least 500 eV.
Claim 52
Dependent Claim
41 words
The device of claim 32 wherein upon emission from the cathode body, electrons have kinetic energies equal to at least 10% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 53
Dependent Claim
41 words
The device of claim 32 wherein upon emission from the cathode body, electrons have kinetic energies equal to at least 40% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 54
Dependent Claim
20 words
The device of claim 32 further comprising phosphor material arranged to receive emitted electrons, thereby being excited to emit light.
Claim 55
Dependent Claim
14 words
The device of claim 51 wherein the phosphor material is disposed on the anode.
Claim 56
Dependent Claim
42 words
The device of claim 32 wherein the vacuum electric field accelerates emitted electrons toward the anode, thereby increasing their kinetic energies by an increment, the increment being less than four times the kinetic energies of electrons upon emission from the cathode body.
Claim 57
Dependent Claim
21 words
The device of claim 32 wherein the body average amplitude of the body electric field is greater than 10 9 V/m.
Claim 58
Dependent Claim
21 words
The device of claim 32 wherein the body average amplitude of the body electric field is greater than 10 10 V/m.
Claim 59
Dependent Claim
33 words
The device of claim 32 wherein the cathode body has a surface and further comprising an emission-enhancing material disposed on the surface, the emitted electrons leaving the cathode body through the emission-enhancing material.
Claim 60
Dependent Claim
90 words
An electron-emissive device comprising: a. a cathode body having a thickness equal to at least 100 μm; b. a voltage source; and c. means for coupling the voltage source to the cathode body so as to impose a body electric field having a body average amplitude across the thickness, imposition of the body electric field causing the cathode body to emit electrons having kinetic energies equal to at least 10% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 61
Dependent Claim
90 words
An electron-emissive device comprising: a. a cathode body having a thickness equal to at least 100 μm; b. a voltage source; and c. means for coupling the voltage source to the cathode body so as to impose a body electric field having a body average amplitude across the thickness, imposition of the body electric field causing the cathode body to emit electrons having kinetic energies equal to at least 10% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 62
Dependent Claim
46 words
The device of claim 57 wherein imposition of the electric field causes the cathode body to emit electrons having kinetic energies equal to at least 40% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 63
Dependent Claim
15 words
The device of claim 58 wherein the thickness is on the order of 1 mm.
Claim 64
Dependent Claim
22 words
The device of claim 58 wherein the body average amplitude over the thickness is between 10 5 V/m and 10 10 V/m.
Claim 65
Dependent Claim
22 words
The device of claim 58 wherein the body average amplitude over the thickness is between 10 5 V/m and 10 9 V/m.
Claim 66
Dependent Claim
27 words
The device of claim 57 wherein the voltage source is configured to impose an accelerating electric field on the electrons upon their emission from the cathode body.
Claim 67
Dependent Claim
39 words
The device of claim 62 wherein the accelerating electric field accelerates emitted electrons, thereby increasing their kinetic energies by an increment, the increment being less than four times the kinetic energies of electrons upon emission from the cathode body.
Claim 68
Dependent Claim
14 words
The device of claim 57 wherein the cathode body is of a wide-bandgap semiconductor.
Claim 69
Dependent Claim
15 words
The device of claim 57 wherein the cathode body is of a group III nitride.
Claim 70
Dependent Claim
13 words
The device of claim 57 wherein the cathode body is of silicon carbide.
Claim 71
Dependent Claim
15 words
The device of claim 57 wherein the thickness is on the order of 1 mm.
Claim 72
Dependent Claim
14 words
The device of claim 57 wherein the voltage source imposes a dc electric field.
Claim 73
Dependent Claim
61 words
The device of claim 57 wherein the cathode body has a surface and further comprising a conductive material disposed on the surface with an interface having a roughness characterized by a radius of curvature less than 15 nm between the cathode body surface and the conductive material, the voltage source electrically contacting the cathode body by means of the conductive material.
Claim 74
Dependent Claim
33 words
The device of claim 57 wherein the cathode body has a surface and further comprising an emission-enhancing material disposed on the surface, the emitted electrons leaving the cathode body through the emission-enhancing material.
Claim 75
Dependent Claim
20 words
The device of claim 57 further comprising phosphor material arranged to receive emitted electrons, thereby being excited to emit light.
Claim 76
Dependent Claim
31 words
The device of claim 71 wherein the phosphor material is in intimate contact with the cathode body so that the emitted electrons enter the phosphor material directly from the cathode body.
Claim 77
Dependent Claim
12 words
The device of claim 57 wherein the cathode body is of diamond.
Claim 78
Dependent Claim
13 words
The device of claim 73 wherein the cathode body is type Ib diamond.
Claim 79
Dependent Claim
19 words
The device of claim 57 wherein the body average amplitude over the thickness is less than 10 9 V/m.
Claim 80
Dependent Claim
19 words
The device of claim 75 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 81
Dependent Claim
19 words
The device of claim 57 wherein the body average amplitude over the thickness is less than 10 7 V/m.
Claim 82
Dependent Claim
19 words
The device of claim 77 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 83
Dependent Claim
27 words
The device of claim 57 wherein imposition of the body electric field causes the cathode body to emit electrons having kinetic energies of at least 50 eV.
Claim 84
Dependent Claim
15 words
The device of claim 79 wherein the thickness is on the order of 1 mm.
Claim 85
Dependent Claim
19 words
The device of claim 57 wherein the body average amplitude over the thickness is less than 10 10 V/m.
Claim 86
Dependent Claim
19 words
The device of claim 81 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 87
Dependent Claim
19 words
The device of claim 57 wherein the body average amplitude over the thickness is less than 10 8 V/m.
Claim 88
Dependent Claim
19 words
The device of claim 83 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 89
Dependent Claim
19 words
The device of claim 57 wherein the body average amplitude over the thickness is less than 10 6 V/m.
Claim 90
Dependent Claim
19 words
The device of claim 85 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 91
Dependent Claim
70 words
An electron-emissive device comprising: a. a cathode body having a thickness equal to at least 100 μm; b. a voltage source; and c. means for coupling the voltage source to the cathode body so as to impose a body electric field having a body average amplitude across the thickness, imposition of the body electric field causing the cathode body to emit electrons having kinetic energies of at least 50 eV.
Claim 92
Dependent Claim
70 words
An electron-emissive device comprising: a. a cathode body having a thickness equal to at least 100 μm; b. a voltage source; and c. means for coupling the voltage source to the cathode body so as to impose a body electric field having a body average amplitude across the thickness, imposition of the body electric field causing the cathode body to emit electrons having kinetic energies of at least 50 eV.
Claim 93
Dependent Claim
46 words
The device of claim 87 wherein imposition of the electric field causes the cathode body to emit electrons having kinetic energies equal to at least 40% of the energy corresponding to completely loss-free acceleration of an electron through the imposed body electric field across the thickness.
Claim 94
Dependent Claim
15 words
The device of claim 87 wherein the thickness is on the order of 1 mm.
Claim 95
Dependent Claim
12 words
The device of claim 87 wherein the cathode body is of diamond.
Claim 96
Dependent Claim
13 words
The device of claim 90 wherein the cathode body is type Ib diamond.
Claim 97
Dependent Claim
14 words
The device of claim 87 wherein the cathode body is of a wide-bandgap semiconductor.
Claim 98
Dependent Claim
15 words
The device of claim 87 wherein the cathode body is of a group III nitride.
Claim 99
Dependent Claim
13 words
The device of claim 87 wherein the cathode body is of silicon carbide.
Claim 100
Dependent Claim
27 words
The device of claim 87 wherein the voltage source is configured to impose an accelerating electric field on the electrons upon their emission from the cathode body.
Claim 101
Dependent Claim
39 words
The device of claim 95 wherein the accelerating electric field accelerates emitted electrons, thereby increasing their kinetic energies by an increment, the increment being less than four times the kinetic energies of electrons upon emission from the cathode body.
Claim 102
Dependent Claim
14 words
The device of claim 87 wherein the voltage source imposes a dc electric field.
Claim 103
Dependent Claim
61 words
The device of claim 87 wherein the cathode body has a surface and further comprising a conductive material disposed on the surface with an interface having a roughness characterized by a radius of curvature less than 15 nm between the cathode body surface and the conductive material, the voltage source electrically contacting the cathode body by means of the conductive material.
Claim 104
Dependent Claim
33 words
The device of claim 87 wherein the cathode body has a surface and further comprising an emission-enhancing material disposed on the surface, the emitted electrons leaving the cathode body through the emission-enhancing material.
Claim 105
Dependent Claim
20 words
The device of claim 87 further comprising phosphor material arranged to receive emitted electrons, thereby being excited to emit light.
Claim 106
Dependent Claim
31 words
The device of claim 100 wherein the phosphor material is in intimate contact with the cathode body so that the emitted electrons enter the phosphor material directly from the cathode body.
Claim 107
Dependent Claim
19 words
The device of claim 87 wherein the body average amplitude over the thickness is less than 10 10 V/m.
Claim 108
Dependent Claim
19 words
The device of claim 102 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 109
Dependent Claim
19 words
The device of claim 87 wherein the body average amplitude over the thickness is less than 10 9 V/m.
Claim 110
Dependent Claim
19 words
The device of claim 104 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 111
Dependent Claim
19 words
The device of claim 87 wherein the body average amplitude over the thickness is less than 10 8 V/m.
Claim 112
Dependent Claim
18 words
The device of claim 106 wherein the body average amplitude over the thickness greater than 10 5 V/m.
Claim 113
Dependent Claim
19 words
The device of claim 87 wherein the body average amplitude over the thickness is less than 10 7 V/m.
Claim 114
Dependent Claim
19 words
The device of claim 108 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
Claim 115
Dependent Claim
19 words
The device of claim 87 wherein the body average amplitude over the thickness is less than 10 6 V/m.
Claim 116
Dependent Claim
19 words
The device of claim 110 wherein the body average amplitude over the thickness is greater than 10 5 V/m.
References Cited (Backward Citations)
US3105166A
Cited
US4672266A
Cited
JPS6417394A
Cited
US5275967A
Cited
US5210430A
Cited
US5202571A
Cited
US5252833A
Cited
US5278475A
Cited
US5334855A
Cited
JPH06208835A
Cited
JPH076687A
Cited
JPH0765701A
Cited
US5552613A
Cited
US5442256A
Cited
US5473218A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-03-16 | 2001-09-15 | 2002-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-03-16 | 2005-09-15 | 2006-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-03-16 | 2009-09-15 | 2010-03-17 | $7700.00 | Window Closed / Lapsed |