US5780867A
Expired / Lapsed
US
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Broadband light-emitting diode
Assignee: National Technology and Engineering Solutions of Sandia LLC
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Filing: 1996-03-07
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Granted: 1998-07-14
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Expires: 2016-03-07
Abstract
Abstract A broadband light-emitting diode. The broadband light-emitting diode (LED) comprises a plurality of III-V compound semiconductor layers grown on a semiconductor substrate, with the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps for generating light in a wavelength range of about 1.3-2 μm. In one embodiment of the present invention, the active region may comprise a first-grown quantum-well layer and a last-grown quantum-well layer that are oppositely strained; whereas in another embodiment of the invention, the active region is formed from a short-period superlattice structure (i.e. a pseudo alloy) comprising alternating thin layers of InGaAs and InGaAlAs. The use a short-period superlattice structure for the active region allows different layers within the active region to be simply and accurately grown by repetitively opening and closing one or more shutters in an MBE growth apparatus to repetitively switch between different growth states therein. The broadband LED may be formed as either a surface-emitting LED or as an edge-emitting LED for use in applications such as chemical sensing, fiber optic gyroscopes, wavelength-division-multiplexed (WDM) fiber-optic data links, and WDM fiber-optic sensor networks for automobiles and aircraft.
Inventors
- 👤 Ian J. Fritz
- 👤 John F. Klem
- 👤 Michael J. Hafich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:13
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/811; H10H20/812; B; B82; B82Y; B82Y20/00
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
66 words
A broadband light-emitting diode (LED) comprising: (a) a plurality of III-V compound-semiconductor layers grown on a substrate, the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps; and (b) electrodes formed above and below the strained-quantum-well active region for electrically activating the LED and generating light within a wavelength range of about 1.3-2 μm.
Claim 2
Dependent Claim
66 words
A broadband light-emitting diode (LED) comprising: (a) a plurality of III-V compound-semiconductor layers grown on a substrate, the semiconductor layers including a pair of cladding layers sandwiched about a strained-quantum-well active region having a plurality of different energy bandgaps; and (b) electrodes formed above and below the strained-quantum-well active region for electrically activating the LED and generating light within a wavelength range of about 1.3-2 μm.
Claim 3
Dependent Claim
19 words
The broadband LED of claim 1 wherein one of the cladding layers includes a semiconductor p-n junction formed therein.
Claim 4
Dependent Claim
27 words
The broadband LED of claim 1 wherein the substrate comprises a III-V compound semiconductor material selected from the group consisting of InP, InAs, GaSb, AlSb, and InGaAs.
Claim 5
Dependent Claim
36 words
The broadband LED of claim 1 wherein the strained-quantum-well active region comprises a substantially lattice-matched quantum-well layer located between a pair of oppositely strained quantum-well layers, with the quantum-well layers further being separated by barrier layers.
Claim 6
Dependent Claim
38 words
The broadband LED of claim 1 wherein the strained-quantum-well active region comprises a plurality of strained quantum-well layers separated by barrier layers, with each quantum-well layer having a different energy bandgap and a different amount of strain therein.
Claim 7
Dependent Claim
16 words
The broadband LED of claim 5 wherein each strained quantum-well layer has about the same thickness.
Claim 8
Dependent Claim
21 words
The broadband LED of claim 5 wherein each strained quantum-well layer has a thickness in the range of about 5-20 nm.
Claim 9
Dependent Claim
31 words
The broadband LED of claim 5 wherein at least one of the strained quantum-well layers has a thickness different from the remaining quantum-well layers for increasing the emission of light therefrom.
Claim 10
Dependent Claim
19 words
The broadband LED of claim 5 wherein a first-grown quantum-well layer and a last-grown quantum-well layer are oppositely strained.
Claim 11
Dependent Claim
17 words
The broadband LED of claim 5 wherein each strained quantum-well layer comprises at least in part InGaAs.
Claim 12
Dependent Claim
30 words
The broadband LED of claim 5 wherein at least one of the strained quantum-well layers comprises a short-period superlattice formed of alternating layers of InGaAs and InGaAlAs of predetermined thicknesses.
Claim 13
Dependent Claim
28 words
The broadband LED of claim 11 wherein the predetermined thicknesses of the InGaAs and InGaAlAs define at least in part the energy bandgap of the strained quantum-well layer.
Claim 14
Dependent Claim
25 words
The broadband LED of claim 11 wherein the active region is substantially strain compensated with the quantum-well layers and the barrier layers being oppositely strained.
Claim 15
Dependent Claim
21 words
The broadband LED of claim 11 wherein the strained quantum-well active region further includes a separate-confinement layer on each side thereof.
Claim 16
Dependent Claim
24 words
The broadband LED of claim 1 wherein light is emitted through at least one of the cladding layers in an upward or downward direction.
Claim 17
Dependent Claim
21 words
The broadband LED of claim 1 wherein at least one of the electrodes includes an aperture therethrough for emitting the light.
Claim 18
Dependent Claim
20 words
The broadband LED of claim 3 wherein the substrate is transparent and the light is emitted downward through the substrate.
Claim 19
Dependent Claim
19 words
The broadband LED of claim 1 wherein light is emitted through a sidewall of the plurality of semiconductor layers.
Claim 20
Dependent Claim
30 words
The broadband LED of claim 1 further including a mesa formed in the plurality of semiconductor layers for defining an active area of the active region for light generation therein.
Claim 21
Dependent Claim
81 words
The broadband LED of claim 1 wherein the substrate is InP, and all the layers forming the active region have semiconductor alloy compositions within an enclosed region labelled "A" in a bandgap energy versus lattice constant diagram of FIG. 6 that is bounded by a first growth state (1, 1, 0) wherein the alloy composition is InGaAs, a second growth state (1, 0, 1) wherein the alloy composition is InAlAs, and a third growth state wherein the alloy composition is InGaAlAs.
Claim 22
Dependent Claim
34 words
The broadband LED of claim 20 wherein the InGaAs alloy composition is approximately In 0 .66 Ga 0 .34 As, and the InAlAs alloy composition is approximately In 0 .52 Al 0 .48 As.
Claim 23
Dependent Claim
23 words
The broadband LED of claim 21 wherein the InGaAlAs alloy composition is approximately In 0 .41 Ga 0 .21 Al 0 .38 AS.
Claim 24
Dependent Claim
92 words
A broadband light-emitting diode (LED) comprising: (a) a semiconductor structure including a plurality of III-V compound semiconductor layers, the semiconductor layers including a pair of cladding layers sandwiched about a strained quantum-well active region having a plurality of different energy bandgaps for emitting light at different wavelengths within a range of about 1.3-2 μm; (b) a mesa formed within the plurality of semiconductor layers for defining an active area of the active region wherein the light is generated; and (c) an electrode formed above the semiconductor structure for electrically activating the LED.
Claim 25
Dependent Claim
92 words
A broadband light-emitting diode (LED) comprising: (a) a semiconductor structure including a plurality of III-V compound semiconductor layers, the semiconductor layers including a pair of cladding layers sandwiched about a strained quantum-well active region having a plurality of different energy bandgaps for emitting light at different wavelengths within a range of about 1.3-2 μm; (b) a mesa formed within the plurality of semiconductor layers for defining an active area of the active region wherein the light is generated; and (c) an electrode formed above the semiconductor structure for electrically activating the LED.
Claim 26
Dependent Claim
19 words
The broadband LED of claim 23 wherein one of the cladding layers includes a semiconductor p-n junction formed therein.
Claim 27
Dependent Claim
16 words
The broadband LED of claim 23 wherein the active region comprises at least in part InGaAs.
Claim 28
Dependent Claim
20 words
The broadband LED of claim 23 wherein light is emitted in an upward or downward direction forming a surface-emitting LED.
Claim 29
Dependent Claim
29 words
The broadband LED of claim 23 wherein light is emitted in a direction parallel to the plurality of layers or at an acute angle thereto forming an edge-emitting LED.
Claim 30
Dependent Claim
38 words
The broadband LED of claim 23 wherein the strained-quantum-well active region comprises a plurality of strained quantum-well layers separated by barrier layers, with each quantum-well layer having a different energy bandgap and a different amount of strain therein.
Claim 31
Dependent Claim
19 words
The broadband LED of claim 28 wherein a first-grown strained-quantum-well layer and a last-grown strained-quantum-well layer are oppositely strained.
Claim 32
Dependent Claim
30 words
The broadband LED of claim 28 wherein at least one of the strained-quantum-well layers has a thickness different from the remaining quantum-well layers for increasing the emission of light therefrom.
Claim 33
Dependent Claim
19 words
The broadband LED of claim 28 wherein the active region further includes a separate-confinement layer on each side thereof.
Claim 34
Dependent Claim
29 words
The broadband LED of claim 28 wherein at least one of the strained-quantum-well layers comprises a short-period superlattice formed of alternating layers of InGaAs and InGaAlAs of predetermined thicknesses.
Claim 35
Dependent Claim
25 words
The broadband LED of claim 32 wherein the active region is substantially strain compensated with the quantum-well layers and the barrier layers being oppositely strained.
Claim 36
Dependent Claim
16 words
The broadband LED of claim 23 further including a semiconductor substrate for supporting the semiconductor structure.
Claim 37
Dependent Claim
27 words
The broadband LED of claim 34 wherein the substrate comprises a III-V compound semiconductor material selected from the group consisting of InP, InAs, GaSb, AlSb, and InGaAs.
Claim 38
Dependent Claim
24 words
The broadband LED of claim 34 further including another electrode formed below the semiconductor structure and in contact with a surface of the substrate.
Claim 39
Dependent Claim
100 words
A broadband light-emitting diode (LED) for generating light in a wavelength range from about 1.3 μm to about 2 μm comprising: (a) a semiconductor structure including a plurality of III-V compound semiconductor layers, with the semiconductor layers including an active region having a plurality of strained quantum-well layers therein separated by barrier layers, each quantum-well layer having a different energy bandgap and a different amount of strain for generating light at a different wavelength; and (b) electrodes above and below the semiconductor structure for directing a flow of an electrical current through the active region to generate the light therein.
Claim 40
Dependent Claim
100 words
A broadband light-emitting diode (LED) for generating light in a wavelength range from about 1.3 μm to about 2 μm comprising: (a) a semiconductor structure including a plurality of III-V compound semiconductor layers, with the semiconductor layers including an active region having a plurality of strained quantum-well layers therein separated by barrier layers, each quantum-well layer having a different energy bandgap and a different amount of strain for generating light at a different wavelength; and (b) electrodes above and below the semiconductor structure for directing a flow of an electrical current through the active region to generate the light therein.
Claim 41
Dependent Claim
30 words
The broadband LED of claim 37 further including a mesa formed in the plurality of semiconductor layers for defining an active area of the active region for light generation therein.
Claim 42
Dependent Claim
30 words
The broadband LED of claim 37 wherein at least one of the strained-quantum-well layers has a thickness different from the remaining strained-quantum-well layers for increasing the emission of light therefrom.
Claim 43
Dependent Claim
16 words
The broadband LED of claim 37 wherein each strained-quantum-well layer comprises at least in part InGaAs.
Claim 44
Dependent Claim
31 words
The broadband LED of claim 37 wherein at least one of the strained-quantum-well layers is formed from a short-period superlattice structure of alternating layers of InGaAs and InGaALAs of predetermined thicknesses.
Claim 45
Dependent Claim
25 words
The broadband LED of claim 37 wherein the active region is substantially strain compensated with the quantum-well layers and the barrier layers being oppositely strained.
Claim 46
Dependent Claim
18 words
The broadband LED of claim 37 wherein the active-region further includes a separate-confinement layer on each side thereof.
Claim 47
Dependent Claim
17 words
The broadband LED of claim 37 wherein the light is emitted in an upward or downward direction.
Claim 48
Dependent Claim
22 words
The broadband LED of claim 37 wherein the light is emitted in a direction substantially parallel to the plurality of semiconductor layers.
Claim 49
Dependent Claim
16 words
The broadband LED of claim 37 further including a semiconductor substrate for supporting the semiconductor structure.
Claim 50
Dependent Claim
26 words
The broadband LED of claim 46 wherein the substrate comprises a III-V compound-semiconductor material selected from the group consisting of InP, InAs, GaSb, AlSb and InGaAs.
Claim 51
Dependent Claim
97 words
A broadband light-emitting diode (LED) for generating light in a wavelength range from about 1.3 μm to about 2 μm comprising: (a) a semiconductor structure including a plurality of III-V compound semiconductor layers, with the semiconductor layers further including an active region having a plurality of strained-quantum-well (SQW) layers therein separated by barrier layers, a first-grown SQW layer of the active region being strained oppositely from a last-grown SQW layer therein; and (b) electrodes above and below the semiconductor structure for directing a flow of an electrical current through the active region to generate the light therein.
Claim 52
Dependent Claim
97 words
A broadband light-emitting diode (LED) for generating light in a wavelength range from about 1.3 μm to about 2 μm comprising: (a) a semiconductor structure including a plurality of III-V compound semiconductor layers, with the semiconductor layers further including an active region having a plurality of strained-quantum-well (SQW) layers therein separated by barrier layers, a first-grown SQW layer of the active region being strained oppositely from a last-grown SQW layer therein; and (b) electrodes above and below the semiconductor structure for directing a flow of an electrical current through the active region to generate the light therein.
Claim 53
Dependent Claim
22 words
The broadband LED of claim 48 wherein the light is emitted in a direction substantially perpendicular to the plurality of semiconductor layers.
Claim 54
Dependent Claim
17 words
The broadband LED of claim 48 wherein each strained quantum-well layer comprises at least in part InGaAs.
Claim 55
Dependent Claim
19 words
The broadband LED of claim 48 wherein the active region further includes a separate-confinement layer on each side thereof.
Claim 56
Dependent Claim
25 words
The broadband LED of claim 48 further including a mesa formed in the plurality of semiconductor layers for defining an area for light generation therein.
Claim 57
Dependent Claim
37 words
The broadband LED of claim 48 further including a semiconductor substrate for supporting the semiconductor structure, with the substrate comprising a III-V compound semiconductor material selected from the group consisting of InP, InAs, GaSb, AlSb and InGaAs.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-07-13 | 2002-01-12 | 2002-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-07-13 | 2006-01-12 | 2006-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-07-13 | 2010-01-12 | 2010-07-14 | $7700.00 | Window Closed / Lapsed |