Patent US4694318A successfully refreshed from Google Patents.
US4694318A
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Sawtooth photodetector
Assignee: Nokia Bell Labs
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Filing: 1984-12-05
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Granted: 1987-09-15
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Expires: 2004-12-05
Abstract
Abstract A structure having a sawtooth graded bandgap region between two layers having the same conductivity type is useful as a photodetector.
Inventors
- 👤 Federico Capasso
- 👤 Won-Tien Tsang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:30
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/223; H10F77/00; H10F77/10; H10F77/12; H10F77/124; H10F77/14; H10F77/146; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/544
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
65 words
In a photodetector comprising first and second substrate-supported regions, said first and second regions having a first conductivity type, a plurality of varying field regions between said first and second regions, said first and second regions having a bandgap at least as great as the smallest bandgap in said varying field region, and first and second electrical contacts to said first and second regions, respectively.
Claim 2
Dependent Claim
65 words
In a photodetector comprising first and second substrate-supported regions, said first and second regions having a first conductivity type, a plurality of varying field regions between said first and second regions, said first and second regions having a bandgap at least as great as the smallest bandgap in said varying field region, and first and second electrical contacts to said first and second regions, respectively.
Claim 3
Dependent Claim
17 words
A photodetector as recited in claim 1 in which said varying field regions comprise graded bandgap regions.
Claim 4
Dependent Claim
29 words
A photodetector as recited in claim 2 in which said graded bandgap regions are graded from a first and lower bandgap value to a second and higher bandgap value.
Claim 5
Dependent Claim
16 words
A photodetector as recited in claim 3 in which said graded bandgap regions are compositionally graded.
Claim 6
Dependent Claim
15 words
A photodetector as recited in claim 4 in which said first conductivity type is p-type.
Claim 7
Dependent Claim
15 words
A photodetector as recited in claim 4 in which said first conductivity type is n-type.
Claim 8
Dependent Claim
28 words
A photodetector as recited in claim 6 further comprising third and fourth regions, said regions having first and second conductivity types, respectively, and contacting said plurality of regions.
Claim 9
Dependent Claim
26 words
A photodetector as recited in claim 1 in which said regions comprise semiconductors selected from the group consisting of Group II-VI and Group III-V compound semiconductors.
Claim 10
Dependent Claim
23 words
A photodetector as recited in claim 1 in which said varying field regions comprise first and second doped regions of opposite conductivity types.
Claim 11
Dependent Claim
28 words
A photodetector as recited in claim 9 further comprising third and fourth regions, said regions having first and second conductivity types, respectively, and contacting said plurality of regions.
Claim 12
Dependent Claim
20 words
A photodetector as recited in claim 10 further comprising an intrinsic conductivity region contacting said first and second doped regions.
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) | 1990-09-14 | 1991-03-16 | 1991-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-14 | 1995-03-16 | 1995-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-14 | 1999-03-16 | 1999-09-15 | $7700.00 | Window Closed / Lapsed |