US4599632A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photodetector with graded bandgap region
Assignee: Nokia Bell Labs
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Filing: 1982-08-30
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Granted: 1986-07-08
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Expires: 2002-08-30
Abstract
Abstract A photodetector having a graded bandgap region is an ultrahigh speed photodetector when operated at zero bias.
Inventors
- 👤 Clyde G. Bethea
- 👤 Federico Capasso
- 👤 Albert L. Hutchinson
- 👤 Barry F. Levine
- 👤 Won-Tien Tsang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:37
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F10/13; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/222; Y; Y02; Y02E; Y02E10/00; Y02E10/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
117 words
A photodetector comprising a first semiconductor region having a first conductivity type and a first bandgap; a second semiconductor region having a second conductivity type; and a third semiconductor region having a first conductivity type and a second bandgap; said second region contacting said first and said third regions, said first bandgap being less than or equal to said second bandgap, said second region having a bandgap graded from a first value adjacent to said third region to a second value adjacent to said first region, said first value being greater than said second value; at least one of said second and first regions being radiation sensitive, and electrical contacts to said first and said third regions.
Claim 2
Dependent Claim
117 words
A photodetector comprising a first semiconductor region having a first conductivity type and a first bandgap; a second semiconductor region having a second conductivity type; and a third semiconductor region having a first conductivity type and a second bandgap; said second region contacting said first and said third regions, said first bandgap being less than or equal to said second bandgap, said second region having a bandgap graded from a first value adjacent to said third region to a second value adjacent to said first region, said first value being greater than said second value; at least one of said second and first regions being radiation sensitive, and electrical contacts to said first and said third regions.
Claim 3
Dependent Claim
18 words
A device as recited in claim 1 in which said first bandgap is less than said second bandgap.
Claim 4
Dependent Claim
16 words
A device as recited in claim 2 further comprising an electrical contact to said second region.
Claim 5
Dependent Claim
22 words
A device as recited in claim 2 or 3 in which said first, second and third regions comprise Group III-V compound semiconductors.
Claim 6
Dependent Claim
34 words
A device as recited in claim 4 in which said Group III-V compound semiconductor comprises Al x Ga 1-x As, x greater than or equal to 0.0 and less than or equal to 1.0.
Claim 7
Dependent Claim
15 words
A device as recited in claim 5 in which said first conductivity type is n-type.
Claim 8
Dependent Claim
20 words
A device as recited in claim 2 or 3 in which said first bandgap is less than said second value.
Claim 9
Dependent Claim
17 words
A device as recited in claim 3 in which said second region-first region junction is reverse biased.
Claim 10
Dependent Claim
15 words
A device as recited in claim 8 in which said first conductivity type is n-type.
Claim 11
Dependent Claim
18 words
A device as recited in claim 9 in which said first bandgap is less than said second value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-07-07 | 1990-01-06 | 1990-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-07 | 1994-01-06 | 1994-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-07 | 1998-01-06 | 1998-07-08 | $7700.00 | Window Closed / Lapsed |