Patent US5407491A successfully refreshed from Google Patents.
US5407491A
Expired / Lapsed
US
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Tandem solar cell with improved tunnel junction
Assignee: University of Houston
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Filing: 1993-04-08
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Granted: 1995-04-18
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Expires: 2013-04-08
Abstract
Abstract A monolithic, tandem photovoltaic device is provided having an indium gallium arsenide tunnel junction lattice-matched to adjoining subcells and having high peak current densities and low electrical resistance. A method is provided for relatively low-temperature epitaxial growth of a subcell over the tunnel junction at temperatures which leave intact the desirable characteristics of the tunnel junction.
Inventors
- 👤 Alexandre Freundlich
- 👤 Mauro F. Vilela
- 👤 Abdelhak Bensaoula
- 👤 Alex Ignatiev
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:52
CPC Classifications
H; H10; H10F; H10F10/00; H10F10/10; H10F10/14; H10F10/142; H10F71/00; H10F71/127; H10F71/1272; H10F77/00; H10F77/10; H10F77/12; H10F77/124; H10F77/1243; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/544
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
118 words
A two-terminal, monolithic, tandem photovoltaic device comprising: a substrate having an upper and lower surface; a first photoactive subcell on the upper surface of the substrate, the first subcell comprising a semiconductor material lattice-matched to the top layer of the substrate and having an energy bandgap; a second photoactive subcell above the first subcell, the second subcell comprising a semiconductor material lattice-matched to the first subcell and having a different energy bandgap than the first subcell; and a tunnel junction, the tunnel junction comprising doped indium gallium arsenide, interconnecting the first and second subcells, the tunnel junction being lattice-matched to the first and second subcells and having a peak current density greater than 50 amperes cm -2 .
Claim 2
Dependent Claim
118 words
A two-terminal, monolithic, tandem photovoltaic device comprising: a substrate having an upper and lower surface; a first photoactive subcell on the upper surface of the substrate, the first subcell comprising a semiconductor material lattice-matched to the top layer of the substrate and having an energy bandgap; a second photoactive subcell above the first subcell, the second subcell comprising a semiconductor material lattice-matched to the first subcell and having a different energy bandgap than the first subcell; and a tunnel junction, the tunnel junction comprising doped indium gallium arsenide, interconnecting the first and second subcells, the tunnel junction being lattice-matched to the first and second subcells and having a peak current density greater than 50 amperes cm -2 .
Claim 3
Dependent Claim
15 words
The device of claim 1 wherein the first subcell is comprised of indium gallium arsenide.
Claim 4
Dependent Claim
14 words
The device of claim 1 wherein the second subcell is comprised of indium phosphide.
Claim 5
Dependent Claim
19 words
The device of claim 1 wherein the tunnel junction is comprised of In 0 .53 Ga 0 .47 As.
Claim 6
Dependent Claim
43 words
The device of claim 4 wherein the dopants for said tunnel junction are selected from the group of n-type dopants consisting of sulfur, tellurium, selenium, germanium, tin, and silicon and the group of p-type dopants consisting of carbon, zinc, cadmium, beryllium, and magnesium.
Claim 7
Dependent Claim
16 words
The device of claim 4 wherein the dopants for said tunnel junction are silicon and beryllium.
Claim 8
Dependent Claim
22 words
The device of claim 4 wherein the peak current density of said tunnel junction is greater than 200 amperes cm -2 .
Claim 9
Independent Claim
91 words
A method for preparing a two-terminal, monolithic, tandem photovoltaic cell, comprising the steps of: providing a substrate having a top layer lattice-matched with indium phosphide; providing on said substrate a subcell lattice-matched to the top layer of the substrate; epitaxially depositing on the first subcell a tunnel junction, the tunnel junction comprising doped indium gallium arsenide; and epitaxially depositing on the tunnel junction a second subcell comprising indium phosphide, the deposition of the second subcell being at a surface temperature in the range from about 300° C. to about 550° C.
Claim 10
Independent Claim
91 words
A method for preparing a two-terminal, monolithic, tandem photovoltaic cell, comprising the steps of: providing a substrate having a top layer lattice-matched with indium phosphide; providing on said substrate a subcell lattice-matched to the top layer of the substrate; epitaxially depositing on the first subcell a tunnel junction, the tunnel junction comprising doped indium gallium arsenide; and epitaxially depositing on the tunnel junction a second subcell comprising indium phosphide, the deposition of the second subcell being at a surface temperature in the range from about 300° C. to about 550° C.
Claim 11
Dependent Claim
21 words
The method of claim 8 wherein the surface temperature is in the range from about 460° C. to about 550° C.
Claim 12
Dependent Claim
21 words
The method of claim 8 wherein the surface temperature is in the range from about 480° C. to about 530° C.
Claim 13
Dependent Claim
15 words
The method of claim 8 wherein the first subcell is comprised of indium gallium arsenide.
Claim 14
Dependent Claim
14 words
The method of claim 8 wherein the second subcell is comprised of indium phosphide.
Claim 15
Dependent Claim
15 words
The method of claim 8 wherein the second cell is deposited using chemical beam epitaxy.
Claim 16
Dependent Claim
15 words
The method of claim 8 wherein the tunnel junction is deposited using chemical beam epitaxy.
Claim 17
Dependent Claim
15 words
The method of claim 8 wherein the first subcell is deposited using chemical beam epitaxy.
Claim 18
Dependent Claim
22 words
The method of claim 8 wherein the first subcell, the tunnel junction, and the second subcell are deposited using chemical beam epitaxy.
Claim 19
Dependent Claim
24 words
The method of claim 8 additionally comprising the steps of depositing a tunnel junction and a third subcell of top of the second subcell.
Claim 20
Independent Claim
111 words
A method for preparing a two-terminal monolithic tandem photovoltaic cell having a patterned tunnel junction, comprising the steps of: providing a substrate having a top layer lattice-matched with indium phosphide; providing on said substrate a lower subcell lattice-matched to the top layer of the substrate, the lower subcell having an upper surface; providing a stop-etch layer on the upper surface of the lower subcell; epitaxially depositing on the stop-etch layer a tunnel junction; patterning the tunnel junction; and epitaxially depositing on the tunnel junction a second subcell comprising indium phosphide, the surface temperature of deposition of the second subcell being in the range from about 300° C. to about 550° C.
Claim 21
Independent Claim
111 words
A method for preparing a two-terminal monolithic tandem photovoltaic cell having a patterned tunnel junction, comprising the steps of: providing a substrate having a top layer lattice-matched with indium phosphide; providing on said substrate a lower subcell lattice-matched to the top layer of the substrate, the lower subcell having an upper surface; providing a stop-etch layer on the upper surface of the lower subcell; epitaxially depositing on the stop-etch layer a tunnel junction; patterning the tunnel junction; and epitaxially depositing on the tunnel junction a second subcell comprising indium phosphide, the surface temperature of deposition of the second subcell being in the range from about 300° C. to about 550° C.
Claim 22
Dependent Claim
15 words
The method of claim 18 wherein the tunnel junction is comprised of indium gallium arsenide.
Claim 23
Dependent Claim
24 words
The method of claim 18 additionally comprising the steps of forming a tunnel junction and a third subcell on top of the second subcell.
Claim 24
Independent Claim
83 words
An device including an indium gallium arsenide tunnel junction, comprising: two subcells formed on opposite sides of the tunnel junction; said tunnel junction comprising indium gallium arsenide; an n-type dopant for said tunnel junction selected from the group of elements consisting of sulfur, tellurium, selenium, germanium, tin, and silicon and a p-type dopant for said tunnel junction selected from the group of elements consisting of carbon, zinc, cadmium, beryllium, and magnesium, the dopant concentrations being greater than 10 18 atoms cm -3 .
Claim 25
Independent Claim
83 words
An device including an indium gallium arsenide tunnel junction, comprising: two subcells formed on opposite sides of the tunnel junction; said tunnel junction comprising indium gallium arsenide; an n-type dopant for said tunnel junction selected from the group of elements consisting of sulfur, tellurium, selenium, germanium, tin, and silicon and a p-type dopant for said tunnel junction selected from the group of elements consisting of carbon, zinc, cadmium, beryllium, and magnesium, the dopant concentrations being greater than 10 18 atoms cm -3 .
Claim 26
Dependent Claim
24 words
The device of claim 21 wherein the proportion of indium, gallium, and arsenic atoms is selected to lattice-match the tunnel junction to indium phosphide.
Claim 27
Dependent Claim
23 words
The device of claim 21 wherein the peak current density of the tunnel junction is greater than 800 amperes per cm 2 .
Claim 28
Independent Claim
69 words
A method of forming a tandem photovoltaic device including a gallium indium arsenide tunnel junction, comprising: providing a first subcell; providing precursor elements of tunnel junction-forming materials; growing the tunnel junction on the surface of said first subcell at a surface temperature in the range from about 300° C. to about 550° C. and a pressure in the range from about 10 -7 torr to about 10 -2 torr.
Claim 29
Independent Claim
69 words
A method of forming a tandem photovoltaic device including a gallium indium arsenide tunnel junction, comprising: providing a first subcell; providing precursor elements of tunnel junction-forming materials; growing the tunnel junction on the surface of said first subcell at a surface temperature in the range from about 300° C. to about 550° C. and a pressure in the range from about 10 -7 torr to about 10 -2 torr.
Claim 30
Dependent Claim
19 words
The method of claim 24 wherein at least one of the precursor elements is provided in an organometallic compound.
Claim 31
Dependent Claim
28 words
The method of claim 24 wherein the tunnel junction is allowed to grow at a surface temperature in the range from about 480° C. to about 530° C.
Claim 32
Independent Claim
79 words
A method of fabricating a single solar cell comprising indium phosphide, the method comprising the steps of: providing a substrate having a top layer lattice-matched with indium phosphide; depositing by chemical beam epitaxy indium phosphide or an alloy in the indium phosphide system on the substrate, the deposition being at a surface temperature in the range from about 300° C. to about 550° C. and a pressure in the range from about 10 -7 to about 10 -2 torr.
Claim 33
Independent Claim
79 words
A method of fabricating a single solar cell comprising indium phosphide, the method comprising the steps of: providing a substrate having a top layer lattice-matched with indium phosphide; depositing by chemical beam epitaxy indium phosphide or an alloy in the indium phosphide system on the substrate, the deposition being at a surface temperature in the range from about 300° C. to about 550° C. and a pressure in the range from about 10 -7 to about 10 -2 torr.
Claim 34
Independent Claim
74 words
A method of fabricating a single solar cell comprising indium gallium arsenide, the method comprising the steps of: providing a substrate having a top layer lattice-matched with indium gallium arsenide; depositing by chemical beam epitaxy indium gallium arsenide on the substrate, the deposition being at a surface temperature in the range from about 300° C. to about 550° C. and a pressure in the range from about 10 -7 to about 10 -2 torr.
Claim 35
Independent Claim
74 words
A method of fabricating a single solar cell comprising indium gallium arsenide, the method comprising the steps of: providing a substrate having a top layer lattice-matched with indium gallium arsenide; depositing by chemical beam epitaxy indium gallium arsenide on the substrate, the deposition being at a surface temperature in the range from about 300° C. to about 550° C. and a pressure in the range from about 10 -7 to about 10 -2 torr.
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) | 1998-04-17 | 1998-10-17 | 1999-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-17 | 2002-10-17 | 2003-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-17 | 2006-10-17 | 2007-04-18 | $7700.00 | Window Closed / Lapsed |