US4278474A
Expired / Lapsed
US
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Device for conversion of electromagnetic radiation into electrical current
Assignee: United States Department of Energy
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Filing: 1980-03-25
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Granted: 1981-07-14
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Expires: 2000-03-25
Abstract
Abstract Electromagnetic energy may be converted directly into electrical energy by a device comprising a sandwich of at least two semiconductor portions, each portion having a p-n junction with a characteristic energy gap, and the portions lattice matched to one another by an intervening superlattice structure. This superlattice acts to block propagation into the next deposited portion of those dislocation defects which can form due to lattice mismatch between adjacent portions.
Inventors
- 👤 A. Eugene Blakeslee
- 👤 Kim W. Mitchell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:50
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H10; H10F; H10F10/00; H10F10/10; H10F10/14; H10F10/142; H10F19/00; H10F19/40; H10F77/00; H10F77/10; H10F77/14; H10F77/146; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/544
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
139 words
A device for direct conversion of electromagnetic radiation to electrical energy comprising, a first ohmic contact, a second ohmic contact, semiconductor means for absorbing electromagnetic radiation positioned between said contacts and including at least first and second portions each of which absorbs electromagnetic radiation in a certain energy spectrum and converts the radiation to electrical energy, with said first portion having a first characteristic electromagnetic energy gap and said second portion having a second characteristic electromagnetic energy gap, said second portion having a lattice structure mismatched to the lattice structure of said first portion, layer means positioned between said first and second portions to substantially block propagation of dislocation defects from one portion to another by substantially preventing the dispersion of said dislocation defects through said layer means, and means for effectuating low resistance electrical contact between said portions.
Claim 2
Independent Claim
139 words
A device for direct conversion of electromagnetic radiation to electrical energy comprising, a first ohmic contact, a second ohmic contact, semiconductor means for absorbing electromagnetic radiation positioned between said contacts and including at least first and second portions each of which absorbs electromagnetic radiation in a certain energy spectrum and converts the radiation to electrical energy, with said first portion having a first characteristic electromagnetic energy gap and said second portion having a second characteristic electromagnetic energy gap, said second portion having a lattice structure mismatched to the lattice structure of said first portion, layer means positioned between said first and second portions to substantially block propagation of dislocation defects from one portion to another by substantially preventing the dispersion of said dislocation defects through said layer means, and means for effectuating low resistance electrical contact between said portions.
Claim 3
Dependent Claim
18 words
The device of claim 1 wherein said means to block propagation of dislocation defects comprises a superlattice structure.
Claim 4
Dependent Claim
63 words
The device of claim 2 wherein one of said portions is the first deposited during fabrication and said means to block propagation of dislocation defects further includes a layer lattice matched to and deposited on said one portion first deposited and a compositionally graded layer between said superlattice structure and said layer lattice matched to and deposited on said one portion first deposited.
Claim 5
Dependent Claim
32 words
The device of claim 3 wherein said first portion consists of a silicon substrate of one conductivity type having a doped upper layer of opposite conductivity type forming a photovoltaic junction therein.
Claim 6
Dependent Claim
12 words
The device of claim 2 wherein said superlattice structure comprises semiconductor materials.
Claim 7
Dependent Claim
59 words
The device of claim 5 wherein said means to block propagation of dislocation defects from said first portion to said second portion includes a lattice matched layer of GaP, a compositionally graded layer of GaAs x P 1-x , and wherein said superlattice comprises alternating GaAs/GaP layers with an average lattice parameter equal to that of said second portion.
Claim 8
Dependent Claim
24 words
The device of claim 1 wherein said means for effectuating low resistance electrical contact between said portions is a highly doped semiconductor tunnel junction.
Claim 9
Dependent Claim
16 words
The device of claim 3 wherein said semiconductor tunnel junction is a highly doped superlattice structure.
Claim 10
Dependent Claim
29 words
The device of claim 1 wherein said energy gaps are positioned in correlation with one another so as to optimize adsorption of the particular incident electromagnetic energy spectral distribution.
Claim 11
Dependent Claim
55 words
The device of claim 1 wherein said first portion has the lowest characeristic energy gap and is positioned at the bottom of said device and said second portion has the highest energy gap and is positioned in said device at the top facing the direction at which the electromagnetic spectrum is intended to be incident.
Claim 12
Dependent Claim
23 words
The device of claim 10 wherein said first and second portions have characteristic energy gaps of approximately 1.0-1.2 eV and 1.6-1.8 eV, respectively.
Claim 13
Dependent Claim
22 words
The device of claim 11 wherein said first portion is Si and said second portion is GaAs 0 .7 P 0 .3.
Claim 14
Dependent Claim
55 words
The device of claim 1 which further includes a third portion having a third characteristic energy gap which is lattice matched to said second portion with layer means positioned between said second and third portions to block propagation of dislocation defects, and means for effectuating low resistance electrical contact between said second and third portions.
Claim 15
Dependent Claim
26 words
The device of claim 13 wherein said first, second, and third portions have characteristic energy gaps of approximately 0.7-1.1 eV, 1.2-1.5 eV, and 1.75-1.9 eV, respectively.
Claim 16
Dependent Claim
19 words
The device of claim 14 wherein said first portion is selected from the group consisting of Ge or Si.
Claim 17
Dependent Claim
31 words
The device of claim 1 which further includes a third portion having a third characteristic energy gap and means for effectuating low resistance electrical contact between said second and third portions.
Claim 18
Dependent Claim
19 words
The device of claim 16 wherein said first portion is selected from the group consisting of Ge or Si.
Claim 19
Dependent Claim
14 words
The device of claim 1 wherein said layer means is a multiple layer means.
Claim 20
Dependent Claim
25 words
The device as described in claim 1, wherein said first and second portions are deposited on a silicon substrate and said first portion comprises silicon.
Claim 21
Independent Claim
120 words
A device for the direct conversion of electromagnetic radiation to electrical energy, comprising a first and second contact means, semiconductor means positioned between said contact means including at least first and second portions each of which absorbs electromagnetic radiation and converts the radiation to electrical energy, with said first portion having a first characteristic electromagnetic energy gap and said second portion having a second characteristic electromagnetic energy gap, said second portion having a lattice structure mismatched to the lattice structure of said first portion, a superlattice member positioned between said first and second portions to substantially block the propagation of dislocation defects from one said portion to the other, and means for effectuating low resistance electrical contact between said portions.
Claim 22
Independent Claim
120 words
A device for the direct conversion of electromagnetic radiation to electrical energy, comprising a first and second contact means, semiconductor means positioned between said contact means including at least first and second portions each of which absorbs electromagnetic radiation and converts the radiation to electrical energy, with said first portion having a first characteristic electromagnetic energy gap and said second portion having a second characteristic electromagnetic energy gap, said second portion having a lattice structure mismatched to the lattice structure of said first portion, a superlattice member positioned between said first and second portions to substantially block the propagation of dislocation defects from one said portion to the other, and means for effectuating low resistance electrical contact between said portions.
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) | 1984-07-13 | 1985-01-12 | 1985-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-13 | 1989-01-12 | 1989-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-13 | 1993-01-12 | 1993-07-14 | $7700.00 | Window Closed / Lapsed |