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WO2009099414A1 - Method of manufacturing a photovoltaic cell - Google Patents

Method of manufacturing a photovoltaic cell Download PDF

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Publication number
WO2009099414A1
WO2009099414A1 PCT/US2008/004522 US2008004522W WO2009099414A1 WO 2009099414 A1 WO2009099414 A1 WO 2009099414A1 US 2008004522 W US2008004522 W US 2008004522W WO 2009099414 A1 WO2009099414 A1 WO 2009099414A1
Authority
WO
WIPO (PCT)
Prior art keywords
metallic substrate
lens
photovoltaic
group
strips
Prior art date
Application number
PCT/US2008/004522
Other languages
French (fr)
Inventor
Lawrence Curtin
Zechariah K. Curtin
Original Assignee
Lawrence Curtin
Curtin Zechariah K
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lawrence Curtin, Curtin Zechariah K filed Critical Lawrence Curtin
Publication of WO2009099414A1 publication Critical patent/WO2009099414A1/en

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/054—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
    • H01L31/0543—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means comprising light concentrating means of the refractive type, e.g. lenses
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/02002—Arrangements for conducting electric current to or from the device in operations
    • H01L31/02005—Arrangements for conducting electric current to or from the device in operations for device characterised by at least one potential jump barrier or surface barrier
    • H01L31/02008—Arrangements for conducting electric current to or from the device in operations for device characterised by at least one potential jump barrier or surface barrier for solar cells or solar cell modules
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022466—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/036—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0392—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • H01L31/03926—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate comprising a flexible substrate
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/52—PV systems with concentrators

Definitions

  • the present invention generally relates to methods of manufacturing photovoltaic cells, more specifically, the present invention relates to methods of manufacturing photovoltaic cells so that the photovoltaic cell produces between two times and two and a half times the cell material's rated output with little increase in cost.
  • Solar energy is a renewable energy source with many well-known advantages over traditional fossil and nuclear energy resources. Solar energy has remained a largely untapped field, however, because the efficiency of existing solar power collection systems is generally too low to justify the required capital investment for these systems.
  • Systems are known for the generation of electrical power through the conversion of solar energy concentrated by a suitable refractor, such as a line-focus Fresnel lens, or a reflector, such as a parabolic trough system.
  • a suitable refractor such as a line-focus Fresnel lens, or a reflector, such as a parabolic trough system.
  • Fresnel lenses are used to collect and focus sunlight onto a narrow-strip photovoltaic array. These lenses are typically made of transparent acrylic sheets or optically clear silicone rubber materials. Glass materials can also be employed to provide structural strength to the design. [007] Despite the obvious advantages of the Fresnel lens, such as operational convenience due to forming the focal region on the concentrator's back side, this approach still has no less obvious shortcomings.
  • Parabolic trough concentrators having much more concentrating power are implemented, for example, in so-called SEGS plants (Solar Energy Generating Systems) in California. These prior art concentrators use parabolic cylinder mirrors made of silvered composite glass to focus sunlight onto tubular solar energy receivers.
  • the parabolic troughs require extremely accurate continuous reflective surfaces of a very large aperture to achieve acceptably high concentration of solar energy.
  • the prior art parabolic trough systems are expensive and heavy, due to the requirements of high optical accuracy.
  • Continuous-surface parabolic mirrors are also not readily adaptable to provide a desired irradiance distribution for the receiver/absorber.
  • a lot of efforts have been made to simplify the parabolic trough concentrators and lower the costs for a solar power system.
  • sheets of anodized aluminum and polymer films have been used for reflective surfaces of troughs. It has been a disadvantage, however, that these thinner mirrors do not have the self-supportive properties of composite glass and require sophisticated support structures to maintain their parabolic shape.
  • the electrons are collected and caused to flow as a current.
  • Various currents and voltages can be supplied through series and parallel arrays of cells.
  • the DC current produced depends on the electronic properties of the materials involved and the intensity of the solar radiation incident on the cell.
  • a conventional solid-state solar cell may include structures such as a semiconductor junction, heterojunction, interface, and thin-film photovoltaics, which may be made from organic or inorganic materials.
  • the necessary elements of these types of devices are a) photon absorption in the semiconductor bulk, b) majority and minority charge carrier transport in the semiconductor bulk, c) a semiconductor band-gap chosen for optimal absorption of the light spectrum and large photovoltages, and d) ideal efficiency limited by open circuit voltages less than the semiconductor band-gap.
  • the photon absorption occurs within the bulk semiconductor and both majority and minority carriers are generated and transported in the bulk.
  • relatively thick, high quality semiconductors are needed.
  • defect free, thick, narrow band-gap, materials are limited in numbers and expensive to fabricate. In heterostructures a limited number of acceptable compatible materials are available.
  • photovoltaic modules must be produced at many times the current volume and at costs below $100/m 2 , as discussed by Bonnet et al. in "Cadmium-telluride material for thin film solar cells", J. Mater. Res., Vol. 13, No. 10 (1998).
  • photovoltaic modules are manufactured in small quantities at costs of about $500/m. 2 .
  • About one hundred times the current yearly production is required to sustain a photovoltaic module manufacturing capacity that can contribute just 5% of the current electricity generated. Consequently, the manufacturing volume of photovoltaic modules needs to be greatly increased and costs significantly reduced.
  • the present invention relates to a method of manufacturing a photovoltaic cell comprising the steps of providing a metallic substrate, depositing a photovoltaic material on a central exposed surface of said metallic substrate, depositing a conductive material on at least one edge of the photovoltaic material, and depositing a clear material on the photovoltaic material.
  • the present inventive method may further comprise the steps of cutting the metallic substrate into strips, bending the metallic substrate strips into a parabolic trough configuration, and disposing a lens between the ends of each of the metallic substrate strips bent into the parabolic trough configuration.
  • Fig. IA depicts a side view of an embodiment of the present invention comprising a metal substrate configured in a roll to roll process.
  • Fig. IB depicts a side view of another embodiment of the present invention comprising a metal substrate configured in a roll to roll process.
  • Fig. 2 depicts a top view of an embodiment of the present invention comprising photovoltaic materials deposited on a metal substrate configured in a sheet process.
  • Fig. 3 depicts a sectional view of an embodiment of the present invention comprising conductive material disposed on the edge of the photovoltaic material.
  • Fig. 4 depicts a sectional view of an embodiment of the present invention comprising a clear material deposited on or adhered to the photovoltaic material.
  • Fig. 5 depicts an embodiment of the present invention wherein metal strips are gradually formed into metallic parabolic troughs.
  • Fig. 6 depicts an embodiment of the present invention having a lens disposed over the top of the respective ends of the formed metallic parabolic trough, such as that shown in Fig. 5.
  • the present invention provides for a novel method of manufacturing photovoltaic cells, wherein the photovoltaic cells may produce at least two to two and a half times the material's rated output.
  • photovoltaic material 15 may be deposited onto a bendable metallic substrate 10 produced in a vacuum chamber, an electrochemical bath, a gravure process, or any other means known within the art.
  • the metallic substrate 10 material may comprise a variety of metals.
  • the metallic substrate 10 may comprise materials including but not limited to Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, and Pb; thin sheets of alloys comprising the above-listed metals such as brass or stainless steel; complex sheets of the above-mentioned metals and their alloys, and the like in view of their low material costs.
  • the metallic substrate 10 may first be cut into any given shape, preferably strips, or the metallic substrate 10 may be used as long sheets, depending on the thickness of the metallic substrate 10. In use, long sheets of the metallic substrate 10 capable of being coiled or rolled, as depicted in Figs.
  • the photovoltaic material 15 may be deposited onto a central exposed upper or lower surface of the metallic substrate 10 in either a roll to roll process (see Fig. IA and IB) or in a sheet process (see Fig. 2).
  • the photovoltaic material 15 of the present invention may comprise any photovoltaic materials known by those skilled in the art to be utilized in photovoltaic cell fabrication including but not limited to Se, Si, TiO 2 , Ru, Ga, As, Ni, Te, Cd, S, C, In, Pt, a-Si, Al, B, Sb, Be, Ca, Cr, Au, I, Ir, Li, Mg, Mo, Pd, P, K, Rh, Cu, Ag, Na, Ta, Sn, Zn, Ge, GaAs, GaNi, CdTe, CdS, and CdSe, but optimally is Si.
  • any photovoltaic materials known by those skilled in the art to be utilized in photovoltaic cell fabrication including but not limited to Se, Si, TiO 2 , Ru, Ga, As, Ni, Te, Cd, S, C, In, Pt, a-Si, Al, B, Sb, Be, Ca, Cr, Au, I, Ir, Li, Mg, Mo, P
  • a masking cover 20 may have first been disposed over at least two parallel edges of the surface of the metallic substrate 10 before the photovoltaic material 15 was deposited. This may be accomplished by employing masking techniques to cover specific areas of an upper and/or lower surface of the metallic substrate 10 with a protective insulating coating or masking cover 20.
  • the masking cover 20 prevents photovoltaic material 15 deposition onto those areas of the metallic substrate 10 and also protects the masked surface area from other possible deleterious effects. All masking techniques known in the art are envisioned, including but not being limited to registered pad printing of an insulative organic coating.
  • a conductive material 25 (e.g. a length of conductive tape) may be disposed along at least one edge of the photovoltaic material 15 on the central exposed surface of the metallic substrate 10.
  • the electrically conductive material 25 may include but is not limited to any of the materials that can transport electrons, holes or ions. Examples of such conductive materials 25 may include but are not limited to simple metals, alloys or transparent conductive oxides (TCO) such as Al, Ag, Pt, Au, Ni, Ti, Mo, W, Fe, V, Cr, Cu, stainless steel, brass, nichrome, SnO 2 , In 2 O 3 , ZnO, and ITO.
  • TCO transparent conductive oxides
  • a clear material 30 may then be deposited over or adhered to the photovoltaic material 15.
  • Examples of such clear material 30 may include but are not limited to oxides such as ZnO, In 2 O 3 , SnO 2 , CdSnO 4 and TiO, wherein these chemical formulae do not always represent their actual stoichiometric ratios in the films. Generally, a higher light transmittance of the clear material 30 layer is preferred.
  • the clear material 30 layer may be deposited by a variety of means known within the art including but not limited to vacuum deposition by means of resistance heating and electron beams, sputtering, ion plating, CVD or spray coating, and the like.
  • the roll or sheet of the metallic substrate 10 having photovoltaic material 15 may then, preferably, be cut into strips 31 and thereafter may be formed into a parabolic trough configuration.
  • the metallic substrate 10 is cut perpendicular to the deposition line of photovoltaic material 15 (depicted in Fig. 2). In this manner, multiple strips are created having photovoltaic material 15 at the central region of each respective strip.
  • each strip 31 may be put into a metal forming device 32 further comprising a pusher element 33.
  • the sides of the metallic substrate 10 having the masking cover 20 without the photovoltaic material 15 disposed thereon may be bent up at an angle to preferably produce a parabolic trough configuration as shown in Fig. 5.
  • the masking cover 20, if used, may then be removed from the at least two parallel edges on the surface of the metallic substrate 10.
  • a lens 35 may be mounted onto the photovoltaic cell so that the lens 35 spans the distance between the respective top ends of the metallic substrate 10 that has preferably been formed into a parabolic trough.
  • the lens 35 may include but is not limited to any lens configuration known within the art such as shaped lens (e.g.
  • the lens 35 material may include any of the class of materials transmissive to light including but not limited to clear plastic, glass, crystal or any other light transmissive material.
  • the present invention enables the efficient production of photovoltaic cells, enables the economical production of photovoltaic cells, and serves to increase material output of such devices with little increase in overall cost of manufacture.
  • Sources of alternative energy are increasingly important in a plurality of applications including land transportation, generation of electric energy in remote locations, and the like.
  • the present invention provides for a much more efficient means of manufacturing, collecting and thereby utilizing the available abundance of solar energy. Such methods and devices act to bring available solar energy to remote regions of the world and provide for a more environmentally-conscience alternative energy solution.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Computer Hardware Design (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Photovoltaic Devices (AREA)

Abstract

A method of manufacturing a photovoltaic cell that is capable of generating a significantly higher rated output for the utilized material. A metallic substrate, in the form of large sheets or rolls, may have a masking cover disposed along at least two parallel edges of the metallic substrate with photovoltaic material deposited therebetween. A length of conductive material may then be disposed on at least one of the edges of the photovoltaic material. A clear material may then be deposited or adhered atop the photovoltaic material. The coated metallic substrate may then preferably be cut into strips, with the strips being bent into a parabolic trough configuration. The masking cover may be removed and a lens, such as a Fresnel lens, may then be secured at the respective ends of the metallic substrate strip forming the parabolic trough configuration.

Description

Method of Manufacturing a Photovoltaic Cell
Cross-reference to related applications
[001] This Patent Cooperation Treaty (PCT) application builds upon previously filed US provisional patent application number 61/063,487 carrying a filing date in the USPTO of February 4, 2008 (04February2008), which is specifically incorporated herein by reference in its entirety.
TECHNICAL FIELD
[002] The present invention generally relates to methods of manufacturing photovoltaic cells, more specifically, the present invention relates to methods of manufacturing photovoltaic cells so that the photovoltaic cell produces between two times and two and a half times the cell material's rated output with little increase in cost.
BACKGROUND ART
[003] Solar energy is a renewable energy source with many well-known advantages over traditional fossil and nuclear energy resources. Solar energy has remained a largely untapped field, however, because the efficiency of existing solar power collection systems is generally too low to justify the required capital investment for these systems.
[004] In the past, radiant energy concentrating devices have been used in space and on Earth to generate heat and electrical current from a light source such as the sun. However, because of the costs associated with capturing, the sunlight in a widely useful form, solar energy has not approached its potential for becoming an important source of power. In particular, it is expensive in terms of capital cost to convert solar energy into electricity, substantially based on the complex manufacturing process involved in making efficient, high-precision solar concentrators with large apertures.
[005] Systems are known for the generation of electrical power through the conversion of solar energy concentrated by a suitable refractor, such as a line-focus Fresnel lens, or a reflector, such as a parabolic trough system.
[006] An approach is known where Fresnel lenses are used to collect and focus sunlight onto a narrow-strip photovoltaic array. These lenses are typically made of transparent acrylic sheets or optically clear silicone rubber materials. Glass materials can also be employed to provide structural strength to the design. [007] Despite the obvious advantages of the Fresnel lens, such as operational convenience due to forming the focal region on the concentrator's back side, this approach still has no less obvious shortcomings.
[008] The refraction index of plastic materials is essentially limited thus restricting concentration power of line-focusing lenses. Prior art refractive lenses are generally bulky and fragile, complicating their manufacturing and use. The use of glass increases the weight, cost, and damage vulnerability of the lens. Furthermore, transparent refractive materials are known to degrade over time, due to interacting with chemicals and ultraviolet radiation.
[009] Parabolic trough concentrators having much more concentrating power are implemented, for example, in so-called SEGS plants (Solar Energy Generating Systems) in California. These prior art concentrators use parabolic cylinder mirrors made of silvered composite glass to focus sunlight onto tubular solar energy receivers.
[0010] The parabolic troughs require extremely accurate continuous reflective surfaces of a very large aperture to achieve acceptably high concentration of solar energy. Thus the prior art parabolic trough systems are expensive and heavy, due to the requirements of high optical accuracy. Continuous-surface parabolic mirrors are also not readily adaptable to provide a desired irradiance distribution for the receiver/absorber. [0011] In the past, a lot of efforts have been made to simplify the parabolic trough concentrators and lower the costs for a solar power system. In particular, sheets of anodized aluminum and polymer films have been used for reflective surfaces of troughs. It has been a disadvantage, however, that these thinner mirrors do not have the self-supportive properties of composite glass and require sophisticated support structures to maintain their parabolic shape.
[0012] Furthermore, it has been a general disadvantage of all conventional retroreflecting devices that operational convenience and use of larger absorbers/accessories or secondary concentrating optics disposed on the path of incoming energy are essentially limited due to unavoidable shadowing of the incident flux.
[0013] Conventional photovoltaic cells convert sunlight directly into electricity ' by the interaction of photons and electrons within the semiconductor material. Most solid-state photovoltaic devices rely on light energy conversion to excite charge carriers (electrons and holes) within a semiconductor material and charge separation by a semiconductor junction producing a potential energy barrier. To create a typical photovoltaic cell, a material such as silicon is doped with atoms from an element with one more or less electrons than occurs in its matching substrate (e.g. silicon). A thin layer of each material is joined to form a junction. Photons, striking the cell, transfer their energy to an excited electron hole pair that obtains potential energy. The junction promotes separation of the electrons from the holes thereby preventing recombinations thereof. Through a grid of physical connections, the electrons are collected and caused to flow as a current. Various currents and voltages can be supplied through series and parallel arrays of cells. The DC current produced depends on the electronic properties of the materials involved and the intensity of the solar radiation incident on the cell.
[0014] Conventional solar cell technologies are based largely on single crystal, polycrystalline, or amorphous silicon. The source for single crystal silicon is highly purified and sliced into wafers from single-crystal ingots or is grown as thin crystalline sheets or ribbons. Polycrystalline cells are another alternative which is inherently less efficient than single crystal solar cells, but also cheaper to produce. Gallium arsenide cells are among the most efficient solar cells available today, with many other advantages, however they are also expensive to manufacture. [0015] In all cases of conventional solid-state photovoltaic cells, photon
(light) absorption occurs in the semiconductor with both majority and minority charge carriers transported within the semiconductor; thus, both electron and hole transport must be allowed and the band gap must be sufficiently narrow to capture a large part of the visible spectrum yet wide enough to provide a practical cell voltage. For the solar spectrum the ideal band gap has been calculated to be approximately 1.5 eV. Conventionally, expensive material and device structures are required to achieve cells that provide both high efficiency and low recombination probability and leakage. [0016] A conventional solid-state solar cell may include structures such as a semiconductor junction, heterojunction, interface, and thin-film photovoltaics, which may be made from organic or inorganic materials. In all of these devices the necessary elements of these types of devices are a) photon absorption in the semiconductor bulk, b) majority and minority charge carrier transport in the semiconductor bulk, c) a semiconductor band-gap chosen for optimal absorption of the light spectrum and large photovoltages, and d) ideal efficiency limited by open circuit voltages less than the semiconductor band-gap. The photon absorption occurs within the bulk semiconductor and both majority and minority carriers are generated and transported in the bulk. For adequate absorbency, relatively thick, high quality semiconductors are needed. However, defect free, thick, narrow band-gap, materials are limited in numbers and expensive to fabricate. In heterostructures a limited number of acceptable compatible materials are available. Schottky barrier based devices have been proposed in this class that rely, again, on absorption of photons in the semiconductor bulk and use the Schottky barrier for charge separation. [0017] Such photovoltaic cells and modules are used to generate electricity from sunlight by the photovoltaic effect. It has been recognized for decades that if these modules could be mass produced at low cost, they could be used to meet a considerable portion of the world's energy needs. Major companies, such as Royal Dutch/Shell and BP-Amoco, have stated that photovoltaic modules have the potential to become a major energy source and that their use has significant benefits to the global environment. However, for these benefits to be realized, photovoltaic modules must be produced at many times the current volume and at costs below $100/m2, as discussed by Bonnet et al. in "Cadmium-telluride material for thin film solar cells", J. Mater. Res., Vol. 13, No. 10 (1998). Currently, photovoltaic modules are manufactured in small quantities at costs of about $500/m.2. About one hundred times the current yearly production is required to sustain a photovoltaic module manufacturing capacity that can contribute just 5% of the current electricity generated. Consequently, the manufacturing volume of photovoltaic modules needs to be greatly increased and costs significantly reduced.
[0018] To realize the required increases in production volume and decreases in manufacturing costs, photovoltaic modules must be produced as a commodity. Commodity level manufacturing requires innovation to develop highly automated production processes and equipment, which are designed to specifically fabricate the commodity product. Commodity manufacturing necessitates high production speeds (high throughput), minimal labor costs, and a continuous process flow. Low capital costs and ease of expanding production capacity also facilitate commodity manufacturing.
[0019] Accordingly, a fundamentally different type of photovoltaic device and method of manufacture is provided by the present invention which can easily incorporate a wide variety of inexpensive materials and which may be, in practice, more efficient having various embodiments of which will be described in more detail below.
[0020] All patents, patent applications and publications discussed or cited herein are incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually set forth in its entirety.
DISCLOSURE OF THE INVENTION
[0021] The present invention relates to a method of manufacturing a photovoltaic cell comprising the steps of providing a metallic substrate, depositing a photovoltaic material on a central exposed surface of said metallic substrate, depositing a conductive material on at least one edge of the photovoltaic material, and depositing a clear material on the photovoltaic material.
[0022] The present inventive method may further comprise the steps of cutting the metallic substrate into strips, bending the metallic substrate strips into a parabolic trough configuration, and disposing a lens between the ends of each of the metallic substrate strips bent into the parabolic trough configuration. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Fig. IA depicts a side view of an embodiment of the present invention comprising a metal substrate configured in a roll to roll process.
[0024] Fig. IB depicts a side view of another embodiment of the present invention comprising a metal substrate configured in a roll to roll process.
[0025] Fig. 2 depicts a top view of an embodiment of the present invention comprising photovoltaic materials deposited on a metal substrate configured in a sheet process.
[0026] Fig. 3 depicts a sectional view of an embodiment of the present invention comprising conductive material disposed on the edge of the photovoltaic material.
[0027] Fig. 4 depicts a sectional view of an embodiment of the present invention comprising a clear material deposited on or adhered to the photovoltaic material. [0028] Fig. 5 depicts an embodiment of the present invention wherein metal strips are gradually formed into metallic parabolic troughs.
[0029] Fig. 6 depicts an embodiment of the present invention having a lens disposed over the top of the respective ends of the formed metallic parabolic trough, such as that shown in Fig. 5.
BEST MODE FOR CARRYING OUT THE INVENTION
[0030] The present invention provides for a novel method of manufacturing photovoltaic cells, wherein the photovoltaic cells may produce at least two to two and a half times the material's rated output. Within the scope of the present invention, photovoltaic material 15 may be deposited onto a bendable metallic substrate 10 produced in a vacuum chamber, an electrochemical bath, a gravure process, or any other means known within the art.
[0031] The metallic substrate 10 material may comprise a variety of metals. Preferably the metallic substrate 10 may comprise materials including but not limited to Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, and Pb; thin sheets of alloys comprising the above-listed metals such as brass or stainless steel; complex sheets of the above-mentioned metals and their alloys, and the like in view of their low material costs. The metallic substrate 10 may first be cut into any given shape, preferably strips, or the metallic substrate 10 may be used as long sheets, depending on the thickness of the metallic substrate 10. In use, long sheets of the metallic substrate 10 capable of being coiled or rolled, as depicted in Figs. IA and IB, are preferable for continuous production of solar cells and may more easily be handled during storage and transportation. The surface of the metallic substrate 10 may be polished, or used "as is" if the surface is finely finished such as with a bright- annealed stainless steel substrate. Alternatively, the substrate surface may be uneven. [0032] As depicted in Figs. 1A-2, the photovoltaic material 15 may be deposited onto a central exposed upper or lower surface of the metallic substrate 10 in either a roll to roll process (see Fig. IA and IB) or in a sheet process (see Fig. 2). The photovoltaic material 15 of the present invention may comprise any photovoltaic materials known by those skilled in the art to be utilized in photovoltaic cell fabrication including but not limited to Se, Si, TiO2, Ru, Ga, As, Ni, Te, Cd, S, C, In, Pt, a-Si, Al, B, Sb, Be, Ca, Cr, Au, I, Ir, Li, Mg, Mo, Pd, P, K, Rh, Cu, Ag, Na, Ta, Sn, Zn, Ge, GaAs, GaNi, CdTe, CdS, and CdSe, but optimally is Si.
[0033] As shown in Fig. 2, a masking cover 20 may have first been disposed over at least two parallel edges of the surface of the metallic substrate 10 before the photovoltaic material 15 was deposited. This may be accomplished by employing masking techniques to cover specific areas of an upper and/or lower surface of the metallic substrate 10 with a protective insulating coating or masking cover 20. The masking cover 20 prevents photovoltaic material 15 deposition onto those areas of the metallic substrate 10 and also protects the masked surface area from other possible deleterious effects. All masking techniques known in the art are envisioned, including but not being limited to registered pad printing of an insulative organic coating.
[0034] As depicted in Fig. 3, after the photovoltaic material 15 has been deposited, a conductive material 25 (e.g. a length of conductive tape) may be disposed along at least one edge of the photovoltaic material 15 on the central exposed surface of the metallic substrate 10. The electrically conductive material 25 may include but is not limited to any of the materials that can transport electrons, holes or ions. Examples of such conductive materials 25 may include but are not limited to simple metals, alloys or transparent conductive oxides (TCO) such as Al, Ag, Pt, Au, Ni, Ti, Mo, W, Fe, V, Cr, Cu, stainless steel, brass, nichrome, SnO2, In2O3, ZnO, and ITO.
[0035] As shown in Fig. 4, a clear material 30 may then be deposited over or adhered to the photovoltaic material 15. Examples of such clear material 30 may include but are not limited to oxides such as ZnO, In2O3, SnO2, CdSnO4 and TiO, wherein these chemical formulae do not always represent their actual stoichiometric ratios in the films. Generally, a higher light transmittance of the clear material 30 layer is preferred. The clear material 30 layer may be deposited by a variety of means known within the art including but not limited to vacuum deposition by means of resistance heating and electron beams, sputtering, ion plating, CVD or spray coating, and the like.
[0036] As depicted in Fig. 5, the roll or sheet of the metallic substrate 10 having photovoltaic material 15 may then, preferably, be cut into strips 31 and thereafter may be formed into a parabolic trough configuration. Preferably, the metallic substrate 10 is cut perpendicular to the deposition line of photovoltaic material 15 (depicted in Fig. 2). In this manner, multiple strips are created having photovoltaic material 15 at the central region of each respective strip. In one embodiment, each strip 31 may be put into a metal forming device 32 further comprising a pusher element 33. In such a metal forming device 32, the sides of the metallic substrate 10 having the masking cover 20 without the photovoltaic material 15 disposed thereon may be bent up at an angle to preferably produce a parabolic trough configuration as shown in Fig. 5. The masking cover 20, if used, may then be removed from the at least two parallel edges on the surface of the metallic substrate 10. [0037] As depicted in Fig. 6, a lens 35 may be mounted onto the photovoltaic cell so that the lens 35 spans the distance between the respective top ends of the metallic substrate 10 that has preferably been formed into a parabolic trough. The lens 35 may include but is not limited to any lens configuration known within the art such as shaped lens (e.g. convex lens), a tall lens, a flat lens, a collimating lens, but preferably is a Fresnel lens or a clear plastic cover. The lens 35 material may include any of the class of materials transmissive to light including but not limited to clear plastic, glass, crystal or any other light transmissive material. [0038] While the above description contains much specificity, these should not be construed as limitations on the scope of any embodiment, but as exemplifications of the presently preferred embodiments thereof. Many other ramifications and variations are possible within the teachings of the various embodiments.
[0039] Thus the scope of the invention should be determined by the appended claims and their legal equivalents, and not by the examples given.
INDUSTRIAL APPLICABILITY
[0040] The present invention enables the efficient production of photovoltaic cells, enables the economical production of photovoltaic cells, and serves to increase material output of such devices with little increase in overall cost of manufacture. Sources of alternative energy are increasingly important in a plurality of applications including land transportation, generation of electric energy in remote locations, and the like. The present invention provides for a much more efficient means of manufacturing, collecting and thereby utilizing the available abundance of solar energy. Such methods and devices act to bring available solar energy to remote regions of the world and provide for a more environmentally-conscience alternative energy solution.

Claims

What is claimed is:
1. A method of manufacturing a photovoltaic cell, said method comprising the steps of: providing a metallic substrate; depositing a photovoltaic material on a central exposed surface of said metallic substrate; depositing a conductive material on at least one edge of said photovoltaic material; and depositing a clear material on said photovoltaic material.
2. The method of claim 1, further comprising the step of: cutting said metallic substrate into strips.
3. The method of claim 2, further comprising the step of: bending said metallic substrate strips into a parabolic trough configuration.
4. The method of claim 3, further comprising the step of: disposing a lens between the ends of each of said metallic substrate strips bent into said parabolic trough configuration.
5. The method of claim 4, further comprising the step of: disposing a masking cover on at least two parallel edges of said surface of said metallic substrate, said masking cover protecting said surface of said metallic substrate located there below.
6. The method of claim 5, further comprising the step of: removing said masking cover from said at least two parallel edges of said surface of said metallic substrate after said metallic substrate has been bent into said parabolic trough configuration.
7. The method of claim 1, further comprising the step of: disposing a masking cover on at least two parallel edges of said surface of said metallic substrate, said masking cover protecting said surface of said metallic substrate located there below.
8. The method of claim 1, wherein said metallic substrate is selected from the group consisting of Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, Pb, thin sheets of alloys comprising at least one material selected from Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, and Pb, and complex sheets comprising at least one material selected from Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, Pb, and said alloys thereof.
9. The method of claim 1 , wherein said photovoltaic material is selected from the group consisting of Se, Si, TiO2, Ru, Ga, As, Ni, Te, Cd, S, C, In, Pt, a-Si, Al, B, Sb, Be, Ca, Cr, Au, I, Ir, Li, Mg, Mo, Pd, P, K, Rh, Cu, Ag, Na, Ta, Sn, Zn, Ge, GaAs, GaNi, CdTe, CdS, and CdSe.
10. The method of claim 1, wherein said conductive material is selected from the group consisting of Al, Ag, Pt, Au, Ni, Ti, Mo, W, Fe, V, Cr, Cu, stainless steel, brass, nichrome, SnO2, In2O3, ZnO, and ITO.
11. The method of claim 1, wherein said clear material is selected from the group consisting of ZnO, In2O3, SnO2, CdSnO4 and TiO.
12. The method of claim 4, wherein said lens is selected from the group consisting of a shaped lens, a tall lens, a flat lens, a collimating lens, a Fresnel lens, and a clear plastic cover.
13. A method of manufacturing a photovoltaic cell, said method comprising the steps of: providing a metallic substrate; depositing a photovoltaic material on a central exposed surface of said metallic substrate; depositing a conductive material on at least one edge of said photovoltaic material; depositing a clear material on said photovoltaic material; cutting said metallic substrate into strips; bending said metallic substrate strips into a parabolic trough configuration; and disposing a lens between the ends of each of said metallic substrate strips bent into said parabolic trough configuration, wherein said lens is selected from the group consisting of a shaped lens, a tall lens, a flat lens, a collimating lens, a Fresnel lens, and a clear plastic cover.
14. The method of claim 13, further comprising the step of: disposing a masking cover on at least two parallel edges of said surface of said metallic substrate, said masking cover protecting said surface of said metallic substrate located there below.
15. The method of claim 14, further comprising the step of: removing said masking cover from said at least two parallel edges of said surface of said metallic substrate after said metallic substrate has been bent into said parabolic trough configuration.
16. The method of claim 13, wherein said metallic substrate is selected from the group consisting of Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, Pb, thin sheets of alloys comprising at least one material selected from Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, and Pb, and complex sheets comprising at least one material selected from Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, Pb, and said alloys thereof..
17. The method of claim 13, wherein said photovoltaic material is selected from the group consisting of Se, Si, TiO2, Ru, Ga, As, Ni, Te, Cd, S, C, In, Pt, a-Si, Al, B,
Sb, Be, Ca, Cr, Au, I, Ir, Li, Mg, Mo, Pd, P, K, Rh, Cu, Ag, Na, Ta, Sn, Zn, Ge, GaAs, GaNi, CdTe, CdS, and CdSe.
18. The method of claim 13, wherein said conductive material is selected from the group consisting of Al, Ag, Pt, Au, Ni, Ti, Mo, W, Fe, V, Cr, Cu, stainless steel, brass, nichrome, SnO2, In2O3, ZnO, and ITO.
19. The method of claim 13, wherein said clear material is selected from the group consisting of ZnO, In2O3, SnO2, CdSnO4 and TiO.
20. A method of manufacturing a photovoltaic cell, said method comprising the steps of: providing a metallic substrate, wherein said metallic substrate is selected from the group consisting of Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, Pb, thin sheets of alloys comprising at least one material selected from Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, and Pb, and complex sheets comprising at least one material selected from Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Cu, Pb, and said alloys thereof.; disposing a masking cover on at least two parallel edges of a surface of said metallic substrate, said masking cover protecting said surface of said metallic substrate located there below; depositing a photovoltaic material on a central exposed surface of said metallic substrate between said at least two parallel edges, wherein said photovoltaic material is selected from the group consisting of Se, Si, TiO2, Ru, Ga, As, Ni, Te, Cd, S, C, In, Pt, a-Si, Al, B, Sb, Be, Ca, Cr, Au, I, Ir, Li, Mg, Mo, Pd, P, K, Rh, Cu, Ag, Na, Ta, Sn, Zn, Ge, GaAs, GaNi, CdTe, CdS, and CdSe; depositing a conductive material on at least one edge of said photovoltaic material, wherein said conductive material is selected from the group consisting of Al, Ag, Pt, Au, Ni, Ti, Mo, W, Fe, V, Cr, Cu, stainless steel, brass, nichrome, SnO2, In2O3, ZnO, and ITO; depositing a clear material on said photovoltaic material, wherein said clear material is selected from the group consisting of ZnO, In2O3, SnO2,
CdSnO4 and TiO; cutting said metallic substrate into strips; bending said metallic substrate strips into a parabolic trough configuration; removing said masking cover from said at least two parallel edges of said surface of said metallic substrate; and disposing a lens between the ends of each of said metallic substrate strips bent into said parabolic trough configuration, wherein said lens is selected from the group consisting of a shaped lens, a tall lens, a flat lens, a collimating lens, a Fresnel lens, and a clear plastic cover.
PCT/US2008/004522 2008-02-04 2008-04-07 Method of manufacturing a photovoltaic cell WO2009099414A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011010751A1 (en) * 2011-02-09 2012-08-09 Osram Opto Semiconductors Gmbh Performing epitaxy process, comprises arranging substrate exhibiting semiconductor surfaces on carrier, heating semiconductor surfaces to temperature provided for epitaxy and epitaxially growing semiconductor material

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5868869A (en) * 1995-06-07 1999-02-09 Photon Energy, Inc. Thin film photovoltaic device and process of manufacture
US5935344A (en) * 1995-10-26 1999-08-10 Sanyo Electric Co., Ltd. Photovoltaic element and manufacturing method thereof
US20010006066A1 (en) * 1998-07-27 2001-07-05 Matthew Cherney Solar energy systems and related hardware
US20060260673A1 (en) * 2003-10-17 2006-11-23 Canon Kabushiki Kaisha Photovoltaic element and method of producing photovoltaic element

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5868869A (en) * 1995-06-07 1999-02-09 Photon Energy, Inc. Thin film photovoltaic device and process of manufacture
US5935344A (en) * 1995-10-26 1999-08-10 Sanyo Electric Co., Ltd. Photovoltaic element and manufacturing method thereof
US20010006066A1 (en) * 1998-07-27 2001-07-05 Matthew Cherney Solar energy systems and related hardware
US20060260673A1 (en) * 2003-10-17 2006-11-23 Canon Kabushiki Kaisha Photovoltaic element and method of producing photovoltaic element

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102011010751A1 (en) * 2011-02-09 2012-08-09 Osram Opto Semiconductors Gmbh Performing epitaxy process, comprises arranging substrate exhibiting semiconductor surfaces on carrier, heating semiconductor surfaces to temperature provided for epitaxy and epitaxially growing semiconductor material

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