US4916708A
Expired / Lapsed
US
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Semiconductor light-emitting devices
Assignee: Eastman Kodak Co
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Filing: 1989-06-26
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Granted: 1990-04-10
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Expires: 2009-06-26
Abstract
Abstract A semiconductor light-emitting device is provided with optical guide layers that include at least part of compositionally graded layers provided adjacent to the light-emitting layer, and at least one end of the compositionally graded layers is provided with a bridging layer wherein the first derivative of each composition profile with respect to the layer thickness is continuous. This provides an extremely smooth change of composition from one layer to the next, and eliminates problems such as overshoot and undershoot, and can be accomplished using a general control system based on PID.
Inventors
- 👤 Toshiro Hayakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:34
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/30; H01S5/34; H01S5/343; H01S5/34326; B; B82; B82Y; B82Y20/00; H01S5/32; H01S5/20; H01S5/2004; H01S5/3211; H01S5/3215; H01S5/323; H01S5/32308; H01S5/32325; H01S5/3409
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
87 words
In a semiconductor light-emitting device including a substrate of semiconductor mixed crystal on which is provided a light-emitting structure that includes a light-emitting layer sandwiched between optical guide layers, each of which includes a compositionally graded layer the improvement comprising: at least one end of each compositionally graded layer being provided with a bridging layer wherein a first derivative of the composition profile with respect to the layer thickness is continuous, so that the bridging layer provides a smooth change of composition profile to an adjacent layer.
Claim 2
Dependent Claim
87 words
In a semiconductor light-emitting device including a substrate of semiconductor mixed crystal on which is provided a light-emitting structure that includes a light-emitting layer sandwiched between optical guide layers, each of which includes a compositionally graded layer the improvement comprising: at least one end of each compositionally graded layer being provided with a bridging layer wherein a first derivative of the composition profile with respect to the layer thickness is continuous, so that the bridging layer provides a smooth change of composition profile to an adjacent layer.
Claim 3
Dependent Claim
24 words
The semiconductor light-emitting device of claim 1 wherein the compositionally graded layer is (Al x Ga 1-x ) 0 .5 In 0 .5 P.
Claim 4
Dependent Claim
26 words
The semiconductor light-emitting device of claim 2 wherein x varies from 0.6 to 0.2 and the light-emitting layer is Ga 0 .5 In 0 .5 P.
Claim 5
Dependent Claim
24 words
The semiconductor light-emitting device of claim 1 wherein the compositionally graded layer is (Al x Ga 1-x ) 0 .47 In 0 .53 As.
Claim 6
Dependent Claim
56 words
The semiconductor light-emitting device of claim 4 wherein x varies from 0.6 to 0.2, and the light-emitting layer is Ga 0 .47 In 0 .53 As and further includes two layers of (Al 0 .2 Ga 0 .8) 0 .47 In 0 .53 As each of which connects the light-emitting layer to a compositionally graded layer.
Claim 7
Dependent Claim
20 words
The semiconductor light-emitting device of claim 2 wherein a bridging is provided on each end of each compositionally graded layer.
Claim 8
Dependent Claim
24 words
The semiconductor light-emitting device of claim 4 wherein the compositionally graded layer is (Al x Ga 1-x ) 0 .47 In 0 .53 As.
References Cited (Backward Citations)
JPS55985A
Cited
US4573161A
Cited
US4512022A
Cited
JPS61164286A
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JPS61184895A
Cited
US4745612A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |