CN204334438U - Aircraft, watercraft or land vehicles - Google Patents

Abstract

Disclose a kind of airborne vehicle, water carrier or land craft at this, comprising: on-plane surface strutting piece; And the multiple solar cells be arranged on on-plane surface strutting piece, each solar cell in wherein said multiple solar cell can bend to meet the non-planar surfaces of described on-plane surface strutting piece, and each solar cell in wherein said multiple solar cell comprises the thin flexible membrane semiconductor body formed by Group III-V compound semiconductor, comprising: first solar subcells with the first band gap; Be arranged on the second solar subcells on described first sub-battery; Be arranged on the classification intermediate layer on the second sub-battery described in described main body; And the 3rd solar subcells, it is on intermediate layer described in described main body, and relative to described second sub-battery lattice mismatch, the described on-plane surface strutting piece it being provided with described multiple solar cell is attached to described airborne vehicle, water carrier or land craft.

Description

Aircraft, watercraft or land vehicles

technical field

The present invention relates generally to solar power systems for converting sunlight into electrical energy, and more particularly to solar cells using III-V compound semiconductors.

Background technique

Commercially available silicon solar cell efficiencies for land-based solar applications range from 8% to 15%. Compound semiconductor solar cells based on III-V compounds have an efficiency of 28% under normal operating conditions and 32.6% under confluence. Furthermore, it is well known that concentrating solar energy onto photovoltaic cells increases the efficiency of the unit.

Considering the low cost and wide availability of silicon solar cells, land-based solar power systems currently use silicon solar cells. Although compound semiconductor solar cells have been used extensively in satellite applications, where power-to-weight efficiency is more important than cost-per-watt considerations in selecting such devices, such solar cells have not yet been designed and configured for As with land-based systems, no land-based solar power system has been configured and optimized to employ compound semiconductor solar cells.

In conventional solar cells constructed with a silicon (Si) substrate, typically one electrical contact is placed on the light absorbing or front side of the solar cell and a second contact is placed on the back of the cell. A light-sensitive semiconductor is disposed on the light-absorbing side of the substrate, and it includes one or more p-n junctions that generate a flow of electrons when light is absorbed within the cell.

The contacts on the light-entry face of the cell typically spread over the surface of the front face in a grid pattern and are typically made of good conductors such as metal. The grid pattern does not cover the entire face of the cell because the grid material, while being a good electrical conductor, is generally opaque to light.

The grid pattern on the face of the cell is usually widely spaced to allow light to enter the solar cell, but not to the extent that the electrical contacts would have difficulty collecting the current generated by the flow of electrons in the cell. Back contacts do not have such diametrically opposed constraints. The back contacts simply serve as electrical contacts, and thus typically cover the entire back surface of the cell. Since the back contact must be a very good electrical conductor, it is almost always made of a metal layer.

This placement of both the anode and cathode contacts on the back of the cells simplifies the interconnection of the individual solar cells in a horizontal array where the cells are electrically connected in series. For silicon cells, such back contact designs are known from PCT Patent Publication WO2005/076960 A2 by Gee et al., and for compound semiconductor solar cells, from U.S. Patent No. Application No. 11/109,016 is known, which is incorporated herein by reference.

Another aspect of land-based solar power systems is the use of concentrating devices, such as lenses and mirrors, to focus incoming solar rays onto a solar cell or array of solar cells. The geometric design of such systems also requires a solar tracking mechanism that allows the plane of the solar cells to continue to face the sun as the sun crosses the sky during the day, thereby optimizing the amount of sunlight incident on the cells.

A further aspect of concentrating device based solar cell configuration design is the design of heat dissipation structures or cooling techniques for dissipating the associated heat generated by intense light incident on the surface of the semiconductor body. Prior art designs, such as those described in PCT International Publication WO 02/080286 Al, published October 10, 2002, employ complex coolant flow paths in thermal contact with the (silicon) photovoltaic cells.

Yet another aspect of the solar cell system resides in the physical structure of the semiconductor materials that make up the solar cell. Solar cells are often fabricated in vertical multi-junction structures and arranged in horizontal arrays, with individual solar cells connected together in electrical series. The shape and structure of the array, and the number of cells it contains, is determined in part by the desired output voltage and current. One type of multijunction structure useful in designs according to the present invention is an inverted metamorphic solar cell structure, such as, as described in U.S. Patent No. 6,951,819 (Iles et al.), Lattice Mismatched Approaches for High Performance, III-V Photovoltaic Energy Converters (Conference Proceedings of 31 ^st IEEE Photovoltaic Specialists Conference, January 3-7, 2005, IEEE Press, 2005); and US Patent Application Publication No. 2007/0277873 A1 (Cornfeld et al.) , which is incorporated herein by reference.

Utility model content

1. Purpose of utility model

It is an object of the present invention to provide an improved multi-junction solar cell.

Another object of the present invention is to provide a solar cell as a thin flexible film conforming to a non-planar support.

Certain implementations or embodiments may achieve less than all of the foregoing.

2. Features of the utility model

Briefly and in general terms, the present invention provides an aircraft, water vehicle or land vehicle, comprising: a non-planar support for mounting a plurality of solar cells; and a plurality of solar cells mounted on the non-planar support , wherein each solar cell in the plurality of solar cells is shaped to conform to the non-planar surface of the non-planar support, and wherein each solar cell in the plurality of solar cells comprises a group III-V compound A thin flexible film semiconductor body formed of semiconductor, comprising: a first solar subcell having a first bandgap; a second solar subcell disposed above said first subcell, having a small second bandgap; a graded intermediate layer composed of InGaAlAs disposed over the second subcell in the body and having a third bandgap larger than the second bandgap; and a third a solar subcell in the body above the intermediate layer and lattice mismatched with respect to the second subcell and having a fourth bandgap smaller than the third bandgap; wherein The non-planar support on which the plurality of solar cells are mounted is attached to the aircraft, water craft or land vehicle.

In another aspect, the utility model provides a solar cell module, which includes: a non-planar support for mounting a plurality of solar cells; and a plurality of solar cells mounted on the non-planar support, wherein the Each solar cell of the plurality of solar cells is capable of bending to conform to the non-planar surface of the non-planar support, and wherein each solar cell of the plurality of solar cells comprises a thin film formed of a III-V compound semiconductor. A flexible film semiconductor body comprising: a first solar subcell having a first bandgap; a second solar subcell disposed above said first subcell, having a second solar subcell that is smaller than said first bandgap a bandgap; a graded intermediate layer composed of InGaAlAs disposed over the second subcell in the body and having a third bandgap greater than the second bandgap; and a third solar subcell, It is above the intermediate layer in the body and is lattice mismatched with respect to the second subcell and has a fourth bandgap smaller than the third bandgap; wherein the solar cell assembly is Attached to an aircraft, water craft or land vehicle. In some embodiments, the non-planar support includes a curved surface.

In another aspect, the present invention provides a method for mounting a plurality of solar cells on an aircraft, water craft, or land vehicle, the method comprising: providing a non-planar support for mounting a plurality of solar cells a battery; mounting the plurality of solar cells on the non-planar support, wherein each solar cell in the plurality of solar cells is capable of bending to conform to the non-planar surface of the non-planar support, and wherein the plurality of solar cells Each of the solar cells comprises a thin flexible film semiconductor body formed of a III-V compound semiconductor comprising: a first solar subcell having a first bandgap; disposed over the first subcell a second solar subcell having a second bandgap smaller than the first bandgap; a graded intermediate layer made of InGaAlAs disposed on the second subcell in the body and having a ratio a third bandgap greater than the second bandgap; and a third solar subcell over the intermediate layer in the body and lattice mismatched with respect to the second subcell and having a ratio a fourth bandgap with a small third bandgap; and attaching the non-planar support on which the plurality of solar cells are mounted to an aircraft, watercraft, or land vehicle. In some embodiments, the non-planar support is adapted for attachment to a curved surface of the aircraft, watercraft or land vehicle.

Certain implementations or embodiments of the invention may incorporate only some of the foregoing aspects.

Description of drawings

Fig. 1 shows the sectional view of the inverse metamorphic solar cell that can be used in the utility model;

2 is a simplified cross-sectional view of an embodiment with electrical interconnections between solar cells 500 and 600, similar to the solar cells shown in FIG. 1 and after additional processing steps;

Figures 3 and 4 show an embodiment where a solar cell assembly as shown in Figure 2 is attached to a support with a non-planar surface, which in turn is attached to an aircraft, watercraft (ship) or land vehicle ;

5 is a perspective view of an exemplary embodiment of a watercraft having a solar assembly attached to a non-planar surface of the watercraft; and

6 is a perspective view of an exemplary embodiment of an aircraft with a solar assembly attached to a non-planar surface of the aircraft.

7 and 8 are perspective views of an exemplary embodiment of a land vehicle with a solar module attached to a non-planar surface of the aircraft.

Additional objectives, advantages and novel features of this utility model will become apparent to those skilled in the art from the present disclosure, including the following detailed description, and by practicing the utility model. Although the invention is described below with reference to exemplary embodiments, it should be understood that the invention is not limited thereto. Those of ordinary skill in the art having the benefit of the teachings of this invention will recognize additional applications, modifications, and embodiments in other fields, which are included within the scope of this invention as disclosed and claimed herein, for which The utility model can also have practicality.

Detailed ways

Details of the invention, including exemplary aspects and embodiments thereof, will now be described. With reference to the drawings and the following description, like reference numerals are used to identify identical or functionally similar parts and are intended to show the main features of the exemplary embodiments in a highly simplified illustration. Furthermore, the drawings are not intended to depict every feature of actual embodiments nor the relative dimensions of the elements shown, nor are they drawn to scale.

The present invention generally relates to a solar power system utilizing III-V compound semiconductor solar cells to convert sunlight into electrical energy.

Figure 1 shows a multi-junction inversion metamorphic solar cell comprising three subcells A, B and C that can be used in one embodiment of the present invention. More specifically, solar cells can be formed using the process in US Patent Application Publication No. 2007/0277873 Al (Cornfeld et al.). As shown in the figure, the top surface of the solar cell includes grid lines 501 deposited directly on top of the contact layer 105 . An anti-reflection (ARC) dielectric layer 130 is deposited over the entire surface of the solar cell. An adhesive is deposited over the ARC layer to hold the cover glass in place. The solar cell structure includes a window layer 106 adjacent to the contact layer 105 . Subcell A (which includes n+ emitter layer 107 and p-type base layer 108 ) is then formed on window layer 106 .

In one embodiment, n+ type emitter layer 107 is composed of InGA(Al)P, and base layer 108 is composed of InGa(Al)P.

Adjacent to the base layer 108 is a back surface field ("BSF") layer 109 deposited to reduce recombination losses. The BSF layer 109 drives minority carriers from regions near the base/BSF interface surface to minimize the effect of recombination losses.

On the BSF layer 109 are sequentially deposited heavily doped p-type and n-type layers 110 which form a tunnel diode, a circuit element that functions to electrically connect battery A to battery B.

A window layer 111 is deposited on the tunnel diode layer 110 . The window layer 11 used in subcell B also operates to reduce recombination losses. The window layer 111 also improves the passivation of the cell surface of the underlying junction. Those skilled in the art will appreciate that one or more additional layers may be added or deleted in the battery structure without departing from the scope of the present invention.

On the window layer 111 of cell B are deposited: an emitter layer 112 and a p-type base layer 113 . In one embodiment, these layers are preferably composed of InGaP and In _0.015 GaAs, respectively, but any other suitable material consistent with the lattice constant and bandgap requirements may also be used.

On cell B is deposited a BSF layer 114 which performs the same function as BSF layer 109 . On top of the BSF layer 114 is deposited a p++/n++ tunnel diode 115, similar to layer 110, again forming the circuit element here functioning to electrically connect battery B to battery C. A buffer layer 115a (preferably InGaAs) is deposited over the tunnel diode 115 and has a thickness of approximately 1.0 microns. Over the buffer layer 115a is deposited a metamorphic buffer layer 116, which is preferably a series of step-graded InGaAlAs layers of composition with a monotonically changing lattice constant to effect the transition of the lattice constant from cell B to subcell C. The bandgap of layer 116 is a constant 1.5 eV, having a slightly larger value than the bandgap of intermediate cell B.

In one embodiment, as suggested in the article by Wanless et al., the step grading comprises nine compositionally graded steps, each step layer having a thickness of 0.25 microns. In one embodiment, the intermediate layer is composed of InGaAlAs with a monotonically varying lattice constant such that the bandgap remains constant at 1.50 eV.

On top of the metamorphic buffer layer 116 is a window layer 117 composed of In _0.78 GaP followed by a subcell C with an n+ emitter layer 118 and a p-type base layer 119 . These layers preferably consist of In _0.30 GaAs in one embodiment.

A BSF layer 120 is deposited over the base layer 119 . The BSF layer 120 performs the same function as the BSF layers 114 and 109 with respect to the battery C.

Over the BSF layer 120 and the metal contact layer 122 is deposited a p+ contact layer 121 , preferably a Ti/Au/Ag/Au layer sequence is applied over layer 121 .

In general, the solar cell assembly is a thin film semiconductor body comprising a multi-junction solar cell which in some embodiments has first and second electrical contacts on its back surface. The module includes a support for mounting the solar cells and making electrical contact with the first and second contacts.

FIG. 2 is a simplified cross-sectional view of one embodiment after additional processing steps and with electrical interconnections between solar cell 500 and solar cell 600 , which are identical to the solar cell shown in FIG. 1 . Batteries are similar. FIG. 2 is a simplified diagram showing only some of the top and lower layers of the solar cell as shown in FIG. 1 . In solar cell 500 , contact pads 520 to grid metal layer 501 are shown adjacent adhesive layer 513 and cover glass 514 . Adhesive layer 613 and cover glass 614 are also shown in solar cell 600 . Cover glasses 514 and 614 are affixed to the top of solar cells 500 and 600 by adhesives 513 and 613, respectively. Cover glasses 514 and 614 are typically about 4 mils thick. While the use of a cover glass is desirable for many environmental conditions and applications, it is not necessary for all implementations and additional layers or structures may be employed to provide additional support or environmental protection to the solar cells.

For solar cells 500 and 600, metal films 125 and 625 are attached to metal contact layers 122 and 622 using bonding layers 124 and 624, respectively. In one embodiment of the present disclosure, bonding layers 124 and 624 are adhesives, such as polyimide (e.g., carbon-loaded polyimide) or epoxy (e.g., B step epoxy resin). In another embodiment of the present disclosure, bonding layers 124 and 624 are solder, such as AuSn, AuGe, PbSn, or SnAgCu. The solder may be eutectic solder.

In some embodiments, metal films 125 and 625 are solid metal foils. In certain implementations, metal films 125 and 625 are solid metal foils (such as Kapton ^™ ) with an adjacent layer of polyimide material. More generally, the material may be a nickel cobalt iron alloy material, or a nickel iron alloy material. In some implementations, metal films 125 and 625 include a molybdenum layer.

In some implementations, metal films 125 and 625 each have a thickness of approximately 50 microns (or, more typically, between 0.001 inches and 0.01 inches). An alternate substrate implementation would be 0.002" Kapton film plus 0.0015" adhesive / 0.002" Mo foil / 0.002" Kapton film plus 0.0015" adhesive for a total thickness of 0.009". However, the Kapton film can be as thin as 0.001" and as thick as 0.01". The adhesive can be as thin as 0.0005" and as thick as 0.005". The Mo foil can be as thin as 0.001" and as thick as 0.005".

FIG. 2 is an illustration of the attachment of an inter-cell electrical interconnect 550 in one embodiment of the disclosure. Electrical interconnection 550 is generally serpentine in shape. The first end is typically soldered to the contact 520, although other bonding techniques may also be used. Electrical interconnection 550 also includes: a second U-shaped portion 552 connected to a first portion extending over the top surface of the cell and rim 510; a third straight portion 553 connected to said second portion and connected to the solar The rim of the cell extends parallel vertically along the side edges of the cell and terminates in a curved contact end portion 554 below the bottom surface of the cell and extending orthogonally to the third portion 553 . The contact end portion 554 is adapted to be directly connected to a bottom contact or terminal of the first polarity of an adjacent second solar cell 600 .

Interconnect 550 may comprise molybdenum, a nickel-cobalt-iron alloy material such as Kovar ^™ , or a nickel-iron material such as Invar ^™ , and may be substantially rectangular in shape with a thickness between 0.0007 inches and 0.0013 inches.

In one aspect of the invention shown in FIG. 3, the solar cell assembly includes a plurality of flexible thin film solar cells 400, 500, 600, 700, and 800 interconnected by electrical interconnects 450, 550, 650, and 750. The solar cell assembly can be shaped to conform to the surface of the support 1002 having a non-planar configuration. Adhesive 1001 may be utilized to attach support 1002 to the surface of an aircraft, water or land vehicle or satellite.

Figure 4 is an expanded view of the solar cell assembly of Figure 3 more clearly showing the curved surface formed by the solar cells attached to a support which in turn is attached to an aircraft, watercraft or land vehicle tools or satellites.

The solar cell assemblies shown in Figures 3 and 4 may, for example, be attached to a non-planar surface of an aircraft, watercraft or land vehicle. Exemplary aircraft, watercraft, and land vehicles may be manned or unmanned (eg, drones).

Exemplary aircraft with non-planar surfaces include light aircraft (which are lighter than air) and heavy aircraft (which are heavier than air). Exemplary light aircraft may include, for example, unpowered devices (eg, balloons, such as hot air balloons, helium balloons, and hydrogen balloons) and powered devices (eg, airships or dirigibles). Exemplary heavy aircraft may include, for example, unpowered equipment (eg, kites and gliders) and powered equipment (eg, airplanes and helicopters). Exemplary heavy aircraft may be fixed wing devices (eg, airplanes and gliders) or rotary wing aircraft (eg, helicopters and rotorcraft).

Exemplary watercraft with non-planar surfaces may be motorized or non-motorized, and may be propelled or tethered. Exemplary watercraft may include surface equipment (eg, ships, boats, and hovercraft) and submersibles (eg, submarines and underwater hovercraft).

Exemplary land vehicles with non-planar surfaces may be motorized (eg, cars, trucks, buses, motorcycles, explorers, and trains) or non-motorized (eg, bicycles).

Figure 5 is a perspective view of an exemplary embodiment watercraft. Submersible craft 904 has a non-planar surface and is attached to platform 903 via tether 902 . The submersible watercraft 904 includes an underwater flotation device 901 which is maintained at a desired depth below the surface by controlling the length of the tether 902 . The solar cell assembly 900 is attached to the non-planar surface of the underwater flotation device 901 . In some embodiments, when light is incident on the solar cell assembly 900 of the submersible watercraft 904, electrical current generated from the solar cell assembly 900 may be provided to the platform 903 via the tether 902.

Figure 6 is a perspective view of an exemplary embodiment aircraft. Aircraft 1000 has non-planar surfaces and is a fixed wing device. Solar cell assembly 1001 is attached to a non-planar surface of a wing of aircraft 1000 . In some embodiments, when light is incident on solar cell assembly 1001 of aircraft 1000, electrical current generated from solar cell assembly 1001 may provide for operation of systems of aircraft 1000 (eg, navigation system, propulsion system, etc.).

Figure 7 is a perspective view of an exemplary embodiment land vehicle. Land vehicle 2000 has a non-planar surface and is a type of automobile. Solar cell assembly 2001 is attached to a non-planar surface of automobile 2000 . In some embodiments, when light is incident on the solar cell assembly 2001 of the automobile 2000, electrical current generated from the solar cell assembly 2001 may provide for the operation of the systems of the automobile 2000 (eg, navigation system, propulsion system, etc.). In some embodiments, vehicle 2000 is a hybrid or electric vehicle.

Figure 8 is a perspective view of another exemplary embodiment land vehicle. Land vehicle 3000 has a non-planar surface and is an exploration vehicle that can be used for land cruising and/or exploration on Earth or other planets. Solar cell assembly 3001 is attached to a non-planar surface of rover 3000 . In some embodiments, when light is incident on the solar cell assembly 3001 of the exploration vehicle 3000, the electrical current generated from the solar cell assembly 3001 can provide power for the systems (e.g., navigation system, propulsion system, etc.) of the exploration vehicle 3000. operate. In some embodiments, exploration vehicle 3000 is a hybrid or electric land vehicle.

While the invention has been described in terms of certain specific embodiments, it is evident that many other modifications and variations will be apparent to those skilled in the art. Accordingly, the invention should be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated by the appended claims and all changes which come within the meaning and range of equivalence thereof are intended to be embraced therein.

While the invention has been described in terms of certain specific embodiments, it is evident that many other modifications and variations will be apparent to those skilled in the art. Accordingly, the invention should be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalence thereof are intended to be embraced therein.

It will be appreciated that each of the elements described above, or two or more together, may also find useful application in other types of constructions than those described above.

Although the invention has been shown and described as being implemented in a solar power system utilizing compound semiconductors, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing from the invention. The spirit of the utility model.

Without further analysis, the foregoing will so fully reveal the gist of the invention that others can easily adapt it to different applications by applying current knowledge, without omitting what constitutes the invention from the point of view of the prior art. general or specific aspects of a rather substantive characteristic feature, and thus such application should be understood to be within the meaning and range of equivalency of the following claims.

Claims (10)

1. airborne vehicle, water carrier or a land craft, comprising:

On-plane surface strutting piece, for installing multiple solar cell; And

Be arranged on the multiple solar cells on this on-plane surface strutting piece, each solar cell in wherein said multiple solar cell can bend to meet the non-planar surfaces of described on-plane surface strutting piece, and each solar cell in wherein said multiple solar cell comprises the thin flexible membrane semiconductor body formed by Group III-V compound semiconductor, comprising:

There is the first solar subcells of the first band gap;

Be arranged on the second solar subcells on described first sub-battery, it has second band gap less than described first band gap;

Classification intermediate layer, is made up of InGaAlAs, and is arranged on the second sub-battery described in described main body, and has three band gap larger than described second band gap; And

3rd solar subcells, it is on intermediate layer described in described main body, and relative to described second sub-battery lattice mismatch, and there is four band gap less than described 3rd band gap;

The described on-plane surface strutting piece wherein it being provided with described multiple solar cell is attached to described airborne vehicle, water carrier or land craft.

2. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said airborne vehicle, water carrier or land craft are manned or unpiloted.

3. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said airborne vehicle is dynamic or motorless aerostat.

4. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said airborne vehicle is dynamic or motorless aerodyne.

5. airborne vehicle, water carrier or land craft as claimed in claim 4, wherein said aerodyne is fixed-wing or rotary wing aircraft.

6. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said water carrier is driven or mooring.

7. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said water carrier is vehicularized or non-motorised.

8. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said water carrier is water surface ship or submersible.

9. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said land craft is vehicularized or non-motorised.

10. airborne vehicle, water carrier or land craft as claimed in claim 1, wherein said classification intermediate layer has substantially invariable band gap, and be series the InGaAlAs layer with the component step-graded of the lattice constant of monotone variation so that with the described 3rd sub-battery Lattice Matching on the described second sub-battery on side and opposite side.