US4471370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Majority carrier photodetector
Assignee: Nokia Bell Labs
•
Filing: 1981-04-24
•
Granted: 1984-09-11
•
Expires: 2001-04-24
Abstract
Abstract A majority carrier photodetector has high sensitivity and fast response times. The photodetector comprises a thin highly doped layer surrounded on either side by two nominally undoped layers which are completely depleted at thermal equilibrium.
Inventors
- 👤 Chung Y. Chen
- 👤 Alfred Y. Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:46
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/24; H10F30/22; H10F30/222
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
99 words
A photodetector comprising as sequentially disposed layers: a first semiconductor layer having a first conductivity type; a second semiconductor layer which is undoped, a third semiconductor layer having a second conductivity type and which is highly doped and thin, a fourth semiconductor layer which is undoped, said second, third and fourth layers being depleted at thermal equilibrium, and a fifth semiconductor layer having a first conductivity type, said fourth and fifth semiconductor layers having bandgaps greater than the bandgaps of said second and third semiconductor layers, first and second electrical contacts to said first and fifth semiconductor layers, respectively.
Claim 2
Dependent Claim
99 words
A photodetector comprising as sequentially disposed layers: a first semiconductor layer having a first conductivity type; a second semiconductor layer which is undoped, a third semiconductor layer having a second conductivity type and which is highly doped and thin, a fourth semiconductor layer which is undoped, said second, third and fourth layers being depleted at thermal equilibrium, and a fifth semiconductor layer having a first conductivity type, said fourth and fifth semiconductor layers having bandgaps greater than the bandgaps of said second and third semiconductor layers, first and second electrical contacts to said first and fifth semiconductor layers, respectively.
Claim 3
Dependent Claim
23 words
A photodetector as recited in claim 1 in which said third layer has a carrier concentration greater than 5×10 17 cm -3 .
Claim 4
Dependent Claim
19 words
A photodetector as recited in claim 2 in which said third layer has a thickness less than 100 Angstroms.
Claim 5
Dependent Claim
24 words
A photodetector as recited in claim 3 in which said second and fourth layers have carrier concentrations less than 5×10 15 cm -3 .
Claim 6
Dependent Claim
20 words
A photodetector as recited in claim 4 in which said carrier concentrations are less than 8×10 13 cm -3 .
Claim 7
Dependent Claim
20 words
A photodetector as recited in claims 1 or 5 in which said second layer is at least 1 μm thick.
Claim 8
Dependent Claim
31 words
A photodetector as recited in claims 1 or 4 in which said semiconductor layers comprise compounds selected from the group consisting of Group II-VI and Group III-V compounds and mixtures thereof.
Claim 9
Dependent Claim
31 words
A photodetector as recited in claim 7 in which said first, second and third semiconductor layers comprise GaAs and said fourth and fifth semiconductor layers comprise Al x Ga 1-x As.
Claim 10
Dependent Claim
15 words
A photodetector as recited in claim 8 in which said first conductivity type is n-type.
Claim 11
Dependent Claim
14 words
A photodetector as recited in claim 9 in which said n-type dopant is silicon.
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) | 1987-09-11 | 1988-03-12 | 1988-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-11 | 1992-03-12 | 1992-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-11 | 1996-03-12 | 1996-09-11 | $7700.00 | Window Closed / Lapsed |