Nanoscale solar energy conversion
20200152814 ยท 2020-05-14
Inventors
Cpc classification
H01L31/02168
ELECTRICITY
H01L31/032
ELECTRICITY
H01L31/035227
ELECTRICITY
H01Q21/22
ELECTRICITY
H01L31/047
ELECTRICITY
Y02E10/547
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
Y02P70/50
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
H01L31/0547
ELECTRICITY
H01L31/036
ELECTRICITY
H01L31/07
ELECTRICITY
Y02E10/52
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
International classification
H01L31/07
ELECTRICITY
H01L31/054
ELECTRICITY
H01L31/036
ELECTRICITY
Abstract
A system for converting solar energy to electric power and a glass for a layer of solar cells in the system. A solar panel installation comprises a solar panel with at least one solar cell formed with a stack of plural layers of photovoltaic wafer material. Each layer of wafer material has an edge direction from a recipient edge to a back edge, and the solar cell is retained within the solar panel installation with the photovoltaic wafer material disposed with the edge direction aligned with incident solar direction. Reflective material applied to facing surfaces of the photovoltaic wafer material facilitates internal reflection of photons. A glass layer has plural sheets of Graphene layered to form a Graphene Cube constructed to exhibit Multiple Excitation Generation (MEG). A method for assembling the glass fixes a top glass above a bottom glass with photovoltaic wafer material establishing a fixed distance therebetween.
Claims
1. A system for the conversion of solar energy to electric power wherein solar light is incident on the system from an incident solar direction, the system comprising: a solar panel installation, the solar panel installation comprising a solar panel; wherein the solar panel comprises at least one solar cell; wherein the solar cell is formed with a layered stack of plural layers of photovoltaic wafer material; wherein each layer of photovoltaic wafer material has a first face surface, a second face surface opposite the first face surface, a recipient edge, a back edge opposite the recipient edge, and an edge direction from the recipient edge to the back edge; and wherein the solar cell is retained within the solar panel installation with the photovoltaic wafer material disposed with the edge direction of the photovoltaic wafer material in an orientation aligned with the incident solar direction.
2. The system of claim 1 further comprising reflective material applied to at least one of the first face surfaces and to at least one of the second face surfaces of one or more of the layers of photovoltaic wafer material of the solar cell thereby to facilitate an internal reflection of photons of solar light incident on the solar panel.
3. The system of claim 2 wherein the reflective material comprises a reflective metal chosen from the group consisting of gold and an alloy of gold.
4. The system of claim 3 further comprising an anti-glare layer applied to at least one surface of the solar cell.
5. The system of claim 1 wherein the photovoltaic wafer material comprises Si and Ge cells.
6. The system of claim 1 further comprising ohmic electrical contacts in electrical communication with the layered stack of plural layers of photovoltaic wafer material.
7. The system of claim 6 wherein the recipient edges of the layers of photovoltaic wafer material are devoid of the ohmic contacts.
8. The system of claim 1 wherein the solar cell further comprises a glass layer.
9. The system of claim 8 wherein the glass layer has plural sublayers and wherein at least one of the sublayers comprises a Graphene sheet.
10. The system of claim 9 wherein the Graphene sheet includes doped Graphene.
11. The system of claim 10 wherein the doped Graphene of the Graphene sheet exhibits a zero eV at 30 degrees chirality to a positive eV at angles above 30 degrees.
12. The system of claim 10 wherein the doped Graphene is formed by a process of immersion in Nitric Acid (HNO.sub.3) for a predetermined time.
13. The system of claim 9 wherein the glass layer further comprises hexagonal Boron Nitrogen (hBN) synthesized with Boron-rich conducting electrodes arched in pure Nitrogen gas.
14. The system of claim 9 wherein there are plural sheets of Graphene layered to form a Graphene Cube.
15. The system of claim 14 wherein the Graphene Cube has resonating antennas operative to resonate to a range of frequencies of photons of light incident on the solar cell to be converted to electrons exhibiting Multiple Excitation Generation (MEG).
16. The system of claim 14 wherein there are plural Graphene Cubes wherein each Graphene Cube has plural sheets of Graphene layered to form the Graphene Cube and wherein each of the sheets of Graphene are separated by one or more hBN layers.
17. The system of claim 16 wherein each Graphene Cube has a top Graphene layer that is an n-type and a bottom layer that is a p-type doped and wherein the one or more hBN layers are electrically connected.
18. The system of claim 16 wherein there are superconductive paths in the one or more hBN layers at 60 degrees chirality.
19. The system of claim 9 wherein there are plural sheets of Graphene layered to form Graphene wafer stacks with four (4) layers of Graphene oxide nanosheets (4-GON).
20. The system of claim 9 wherein there are plural sheets of Graphene layered to form Graphene wafer stacks with eight (8) layers of Graphene oxide nanosheets (8-GON).
21. A glass for a layer of a solar cell wherein the glass comprises plural sublayers and wherein at least one of the sublayers comprises a Graphene sheet.
22. The glass of claim 21 wherein the Graphene sheet includes doped Graphene.
23. The glass of claim 22 system wherein the doped Graphene of the Graphene sheet exhibits a zero eV at 30 degrees chirality to a positive eV at angles above 30 degrees.
24. The glass of claim 21 wherein the glass layer further comprises hexagonal Boron Nitrogen (hBN) synthesized with Boron-rich conducting electrodes arched in pure Nitrogen gas.
25. The glass of claim 21 wherein there are plural sheets of Graphene layered to form a Graphene Cube.
26. The glass of claim 25 wherein the Graphene Cube has resonating antennas operative to resonate to a range of frequencies of photons of light incident on the solar cell to be converted to electrons exhibiting Multiple Excitation Generation (MEG).
27. The system of claim 25 wherein there are plural Graphene Cubes wherein each Graphene Cube has plural sheets of Graphene layered to form the Graphene Cube and wherein each of the sheets of Graphene are separated by one or more hBN layers.
28. A method for assembling glass for a layer of a solar cell with Graphene wafer stacks, the method comprising: a) inserting a bottom glass into a tube; b) fixing the bottom glass in place; c) thermally transferring Type B hBN to the bottom glass, positioned in a chemically-etched passivation layer to electrically connect to form an anode connection to form a Trilogy Solar Cell; and d) positioning a top glass above the tube that contains the bottom glass with a layered stack of plural layers of photovoltaic wafer material attached to the top glass.
29. The method of claim 28 wherein a distance between the top glass and the bottom glass is fixed at approximately 2.7 nm.
30. The method of claim 28 wherein the tube comprises a Square Glass Tube (SGT).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The invention will be described and explained with additional specificity and detail with reference to the accompanying drawings in which:
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DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0062] The systems and methods for the conversion of solar energy to electric power disclosed herein are subject to a wide variety of embodiments. However, to ensure that one skilled in the art will be able to understand and, in appropriate cases, practice the present invention, certain preferred embodiments of the broader invention revealed herein are described below and shown in the accompanying drawing figures.
[0063] The disclosed solar panels, arrays of such solar panels, and methods for manufacturing solar panels seek to achieve improved efficiency in converting solar energy to electric energy thereby to realize enhanced capacity per square meter of solar panel surface at a reduced capital cost per watt. The solar panels, arrays of solar panels, and methods for manufacturing solar panels may exploit one or more advances described herein. As shown in the attached drawings and described further below, solar panels as disclosed herein can demonstrate improved efficiency through the selection of materials for solar cells with band gaps enabling the capture of a large portion of the high energy photons present in the Sun's solar spectrum. Further, the crystalline structure of the solar cell material can be oriented for alignment with incident light to achieve optically parallel operation and direct illumination with the goal of reducing the thickness of costly materials and reducing efficiency-robbing heat. Still further, embodiments are contemplated wherein a reflective cavity is provided in each solar cell that reflects or ping pongs photons to increase their chances of absorption and being turned into electrical power.
[0064] A schematic of the fabrication steps to manufacture direct solar cells from wafers 12 is depicted in
[0065] It will be understood that the characteristics of the wafers 12 and of the stack 14 of wafers 12 can vary within the scope of the invention. By way of a non-limiting example, the stack 14 in a preferred embodiment has thirty (30) Si wafers of 10 mils (250 microns) thickness; sixteen (16) Ge wafers of 10 mils (250 microns) thickness; and two (2) conductive wafers of 10 mils (250 micron) thickness. The resulting stack 14 of thirty-eight (38) wafers 12 has a height of one and two-tenths (1.2) centimeters.
[0066] A saw pattern is applied to the top wafer 12 as is shown in
[0067] Looking to
[0068] As
[0069] The cells 20 of solar panels according to the invention can thus act as edge-illuminated cells 20 with edges of the crystalline structure of the materials of the solar cell 20 retained to be aligned with incident light 100. Such an orientation achieves direct illumination of the photovoltaic material of the cell 20 thereby to increase the efficiency of the capture of solar energy by the solar cell 20 and the conversion of that energy into electric power.
[0070] In relation to the foregoing, it is noted that NASA's Lewis Research Center in Cleveland, Ohio, performed testing on an edge-illuminated solar cell. In the table below, NASA's results are scaled, based on the comparative characteristic, to estimate the operational parameters for an embodiment of the present invention utilizing the dual materials of Si and Ge made from a stack of thirty-eight (38) wafers.
TABLE-US-00001 NASA Present Invention Junctions, Number 23 30 Area, cm 0.49 1.2 Suns, Number 207 85.5 Per Junction Voltage 0.4 0.4 E, volts 9.2 12 Efficiency, % 17.4 35 Current, I, ma 151 550
It will be underscored that the foregoing and any other estimates and calculations set forth herein are predicted, anticipated, or desired results only and should not be interpreted as representations of actual performance unless and until verification in practice is achieved and made of record.
[0071] Efficiency. The overall efficiency of solar cells 20 for embodiments of the present invention is dependent on the sum of the efficiency of each of the operations. Therefore, the increase in overall efficiency that is projected for embodiments of solar cells 20 and solar panels 10 incorporating such cells 20 will be dependent on the sum of the increases in efficiencies of plural operations, which may include solar tracking in comparison to stationary panels; dual-junction compared to single junction; direct versus indirect photovoltaic material; and multiple pass reflective cavities in comparison to single passes of light. Overall, preferred embodiments of the present invention incorporating the cumulation of the developments disclosed herein are projected to have an efficiency of double that of the conventional silicon technology or approximately forty percent (40%) compared to the twenty percent (20%) of conventional panels.
[0072] Electric Circuit. In embodiments of the solar panel 10 disclosed herein, the voltage per junction for Si and Ge may preferably be 0.4 v and 0.677 v, respectively. Where a wafer stack 14 of cells 20 has thirty (30) Si cells 24, they are calculated to produce a total seven and one-half (7.5) volts, and the sixteen (16) Ge cells 25 are calculated to produce a total of seven and on-half (7.5) volts. As in
[0073] Graphene Quantum Dots (GQDs). Graphene, a special form of Carbon, can be produced by pulverizing and acid-etching coal. Multi junction solar cells 20 can be manufactured exploiting quantum, very small, dots of Graphene sequenced to have band gaps that are closely matched to the energy of the photons at the wavelength of light equal to the central response of the solar spectrum to capture the solar spectrum and to achieve an improved efficiency, such as is predicted to be greater than sixty percent (60%). The ability to produce GQDs of different band gaps comes from the use of different grades of coal as source material coupled with different synthesis temperatures and is further based on the operating pH.
[0074] Comparison of the Present Invention's Panel to Rectangular Solar Panels of the Prior Art. Manufacturing plants for the present invention's panels 10 can be designed to incorporate the advantages of prior art production facilities while providing concomitant advances thereover. With limited automation, for instance, it is predicted that 75 semi-skilled production workers may be employed for each of the three shifts per day, seven days a week. The panels 10 disclosed herein, on a power generation basis, cost significantly less than the cost of manufacture of panels of the prior art with the disclosed panel 10 replacing expensive polycrystalline silicon, which is taught to occupy 95% of the panel's real estate. It is also contemplated that inexpensive parabolic mirror subassemblies 30 can be employed to occupy, for example, 99% of the area of the panel 10 as according to predicted performance data.
[0075] Graphene quantum dots (GQDs). Coal is a fossil fuel that is, essentially, the altered remains of prehistoric vegetation. However, there are different coal types. Coal originally began to form during the Carboniferous period, which took place between 360 and 290 million years ago. Put simply, plant matter accumulated in swamps and peat bogs, and after being buried and exposed to high heat and pressurelargely due to the shifting of tectonic platesit was transformed into coal.
[0076] The quality of coal is largely determined by the type of vegetation the coal originated from the coal's, depth of burial, the temperatures and pressures at that depth, and how long it took the coal to form. These factors contribute to the degree of transformation of the original plant material to carbon, and it is carbon content that determines a coal's rank. Essentially, higher carbon content is associated with coal that has spent a longer time forming, while lower carbon content is a characteristic of younger coal.
[0077] The two main coal types of coal of interest in the present invention, arranged from lowest to highest carbon content, are Bituminous coal and Anthracite coal. Bituminous coal is harder and blacker than lignite and sub-bituminous coal, and can be divided into two types: thermal and metallurgical. Together, they make up 52 percent of the world's coal reserves. Thermal coal is mostly used for power generation, cement manufacturing and other industrial purposes, while metallurgical coal is used primarily for manufacturing iron and steel. Anthracite coal is the most mature coal and thus has the highest carbon content of any type of coal. It is frequently used for home heating and, accounting for about 1 percent of the world's total coal reserves, represents a very small portion of the overall market. Anthracite coal can be used as a smokeless fuel in domestic and industrial contexts.
[0078] In addition, Coke is a source material of interest in embodiments of the present invention. Coke is prepared by removing the volatile materials from coal by heating in a process called coking in which carbonization occurs.
[0079] Coal is a low-cost energy resource. Even though the structure of coal is complex, the simplified composition contains angstrom or nanometer-sized crystalline carbon domains with defects that are linked by aliphatic amorphous carbon. Coal is still mainly used as an energy source, in contrast to crystalline carbon allotropes, such as fullerenes, graphene, graphite and diamond, that have found applications in electronics, physics, chemistry and biology.
[0080] Graphene quantum dots (GQDs) have been synthesized or fabricated from various carbon-based materials. Physical approaches such as lithography, to etch the size of graphene to about 20 nm, are expensive and are impractical for production in bulk quantities for mass production versus laboratory scale production applications.
[0081] Coal's structural characteristics create a perception that coal is only useful for producing energy by combustion. The crystalline carbon within the coal structure is easier to oxidize and displace through an inexpensive wet-chemical method that synthesize wavelength tunable Graphene Quantum Dots (GQDs) from bituminous coal, anthracite coal, and coke resulting in nanometer-sized GQDs with amorphous Carbon added on the edges. The GQDs isolated by the wet-chemical method yield up to four hundred (400) pounds of GQDs per ton of coal or coke.
[0082] In the following, the wave length of photoluminescence of a photovoltaic GQD is used to express what has been previously referred to as the photon's wave length of light equal to the solar spectrum central response of the photovoltaic material.
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[0084] Source Material. The GQDs synthesized from bituminous coal and anthracite coal and Coke pursue different structures. The GQDs produced from three source materials are soluble and fluorescent in aqueous solution.
[0085] Reaction Temperature. The production solution, held for 24 hours, produces GQDs with photoluminescence properties in different ranges based on the selection of the reaction temperature in the 100 or 120 C. for operating range.
[0086] Solution pH. Photoluminescence emission is pH-dependent in the range of pH 3 to pH 10. The GQDs sourced from Bituminous coal exhibit a maximum intensity at pH 6 and pH 7. When the pH changed from pH 6 to pH 3, a red wavelength shift occurs from 500 to 540 nm. When the pH increased from 7 to 10, a blue wavelength shift occurs to 460 nm.
[0087] The maximum intensity emissions for the GQD sourced from anthracite coal is 530 nm, orange-yellow. The maximum intensity emissions for the GQD sourced from bituminous coal is 460 nm, blue fluorescence. When manufacturing conditions are selected to change the size of the GQD sourced from bituminous coal changed from 2.96 nm to 2.30 nm, the emission wavelength blue shifted from 500 to 460 nm the maximum intensity emissions for the GQD sourced from Coke is 480 nm, green.
[0088] Synthesis of GQDs from Coals or Coke. In one practice of the manufacturing procedure, one can measure a given mass of coal or coke source material, such as 300 mg. The source material is suspended in a blend of concentrated sulfuric acid (60 ml) and nitric acid (20 ml). The blended material is mixed, such as by placement in a sonic mixer and held, such as for two (2) hours. The blended material is then stirred and heated in a constant temperature oil bath at a selected temperature in the range of 100 to 120 C. and held for twenty-four (24) hours. The solution is then cooled to room temperature before adding a sufficient volume of three molar (3 M) Sodium Hydroxide (NaOH) to adjust the mixture to 7 pH. The neutralized mixture is then filtered through a 0.45-m membrane filter and subsequently purified in a 1,000 Da bag and held for five (5) days. After purification, the solution is concentrated, using rotary evaporation, to obtain solid GQDs. The GQDs prepared from coals and coke can then serve as multiple junctions in solar cells according to the invention that can be placed in illumination series to capture increased solar energy.
[0089] The conventional wisdom is that solar cells made from a single material, silicon, absorb and convert into electrical energy all photons that have greater energy than the material's threshold energy. The present inventor proposes that this is not wholly accurate, that the only photons converted into electrical energy are ones that are in a narrow range above and below the material's threshold energy.
[0090] On Earth, solar cells made from a single material have been found to achieve an efficiency of approximately 20% for conversion of solar energy into electrical energy. In space, solar cells made from three materials have been found to have an efficiency of approximately 40% for conversion of solar energy to electrical energy. In space, it is known to place three materials in optical series by layering the materials in by epitaxial growth, which is a costly process used in the manufacture of semiconductor devices. The present invention teaches a 90-degree rotation of the three materials with respect to incident light and seeks to achieve the same efficiency as in space, approximately 40%. Photovoltaic materials, such as gallium arsenide, silicon, and germanium, are disposed in optical parallel operation as shown in
[0091] The optically parallel operation depicted in
[0092] In a quest to identify the elemental materials to produce high-efficiency solar cells 20, focus can be had to the area of the periodic table containing the elements that produced organic matter. A clue as to where to focus may be had by reference to the Periodic Table. Of the 118 elements, only five (5) elements, namely Carbon (C), Hydrogen (H), Silicon (Si), Nitrogen (N) and Oxygen (O), account for 98.5% of all organic matter by weight. These elements, except for Oxygen (O), are positioned in Table I below as in the periodic table with adjacent elements used as dopants. Hydrogen (H) is positioned above the Group 13 elements. Also included for each element are the values of Pauling's Electronegativity Scale value, which is a measure of the ability of the element to attract electrons to itself in a covalent bond.
[0093] The atomic number of a chemical element is the number of protons found in the nucleus of an atom. Just as Lithium (Li), the lowest atomic number metal, is the material of choice for batteries due to ease of electron movement in the conductive band, Carbon (C) is, for a similar reason, a superior material choice to Silicon for solar cells, and Boron (B) and Nitrogen (N) are superior dopant materials as compared to Aluminum (Al) and Phosphorus (P).
[0094] The solar cell 20 is doped to produce an n-type semiconductor or p-type semiconductor and then capped with dopants on the Sun illumination side of the cell 20 with n-type and p-type dopants on the opposite side. The dopant elements of choice for Silicon solar cells, Boron for p-type and Nitrogen (N) for n-type, are the same as for the elements used in a Carbon (C) Solar Cell according to the present invention. The difference in electronegativity of the base elemental materials, Silicon and Carbon, and the dopants, Boron and Nitrogen (N), is shown in the following Table 2:
[0095] The Carbon (C) solar cell 20 according to the invention provides an almost equal balance of dopant electronegativity with positive 0.51 relative to Boron (B), employed as the p-type dopant, and negative 0.49 relative to Nitrogen (N), employed as the n-type dopant. The Silicon solar cell 20 provides both negative electronegativities for the dopants relative to the Silicon (Si) base material and can only function as a solar cell because the Boron (B) dopant is less electron negative relative to Nitrogen (N). The electronegativity of Hydrogen (H), positive 2.1, is comparable to the electronegativity of Boron (B), positive 2.04, resulting in a comparable difference in electronegativity relative to Carbon (C) to create favorable conditions for electron movement.
[0096] As shown in
[0097] In one example of the present invention as in
[0098] Graphene is the material of choice for the solar panel. The source of Graphene can progress, for instance, from Vapor deposition in six-inch squares on Copper to thirty-inch wide film. According to the invention, a lower cost alternative for production of Graphene is the carbonization and processing of the stalk of hemp. In one practice of the invention, for example, the blast fiber is converted to Graphene by first carbonizing, such as at 180 degrees C. for 24 hours at moderate pressure, followed by treating with Potassium Hydroxide, and finally by heating and holding at 800 degrees C.
[0099] The total thickness of the Graphene layers can be scaled to the size of the Graphene Quantum Dot (GQD) that produces a spectral adsorption with the added efficiency benefit of alignment by self-assembly and direct connection to ballistic transport hBN rather than the less efficient method of Graphene Quantum Dots of transport through liquid contact.
[0100] Looking to
[0101] Manifestations of the present invention can use Graphene sheets. When intersected with a perpendicular plane and rotated, Graphene sheets move from a zero eV, characteristic of a metal, to a positive eV, characteristic of a semiconductor, to an infinite eV, characteristic of an insulator. In the present invention, the Graphene is doped so that, when the same perpendicular plane is rotated, the Graphene moves from a zero eV at 30 degrees chirality, characteristic of a metal, to a positive eV, characteristic of a semiconductor at all other angles.
[0102] In a preferred embodiment of the present invention, eight (8) Graphene sheets are doped that have been grown to self-assemble in alignment from Methane (CH.sub.4) and Hydrogen (H.sub.2) gas in the presence of a transition metal catalyst, such as Cobalt (Co), Nickel (Ni), or another transition metal catalyst. Doping an eight (8) sheet assembly can be accomplished, for instance, by immersion in 63%, by weight, Nitric Acid (HNO.sub.3) for 10 minutes.
[0103] Under the present invention, the Graphene sheet assembly (GSA) is a canvas over which the resonant primary frequency and harmonics are superimposed somewhat like antenna lengths and are based on electron path length formed by the number of sheets of Graphene. The primary frequency of the GSA is based on: 1) the assembly's total thickness, which could in one non-limiting example be 4.61 nm (100.335 films+90.14 spaces) resembling the 4 nm diameter GQD that resonates with 580 nm, Yellow (570 to 590 nm) solar spectrum light; 2) the first half harmonic, with a length of 2.3 nm, that resembles the 2 nm diameter GQD that resonates with 480 nm, Blue (450 to 495 nm) solar spectrum light; and 3) the second quarter harmonic, with a length of 1.15 nm resembles a 1 mm diameter GQD that resonates with 380 nm, Violet (380-450 nm), or more accurately near UV, solar spectrum light.
[0104] The energy available increases as resonance occurs for each photon moving from the primary frequency that corresponds to Yellow's, 2.1 eV, to the first resonant frequency that corresponds to Blue's, 2.6 eV, and finally to the second resonant frequency that corresponds to near UV, or an estimated 3.2 eV. As theorized hereunder, the presence of high electron volt photons opens the possibility for the occurrence of Multiple Excitation Generation (MEG) with individual photons achieving greater than 100% efficiency.
[0105] Light is absorbed by the Carbon, which has a higher resistance than metal for all planes of rotation that are perpendicular to the sheet. Under the invention, the Carbon is doped to increase its conductivity. One side of the Carbon is positioned adjacent to Boron, which has a valence of three electrons in its outer shell. The valance of Boron is one lower than the valance of the Carbon, which has 4 electrons in its outer shell, and the other side of the Carbon is positioned adjacent to Nitrogen with a valence having 5 electrons in its outer shell, one higher than the other valance of Carbon. As schematically depicted in
[0106] For all perpendicular planes to the Graphene sheet other than the plane that is at the Chiral, 30 degrees, the Graphene is a p-type doped semiconductor. At the Chiral plane as shown in
[0107] In an embodiment of the present invention, the synthesis of hBN employs Nitrogen free, Boron-rich conducting electrodes arched in pure Nitrogen gas. The electrodes incorporate a very small amount of Nickel (Ni) and Cobalt (Co) as catalysts. The electrode can be formed from 99% pure Boron to which one percent, 1%, by weight of each catalytic metal is added. Both Nitrogen (N) and Boron (B) have stable isotopes that contain one neutron more in their nucleuses. The heavier isotopes have reduced electron mobility due to the greater attractive forces of the heavier nucleuses. Nitrogen-15 is present at only 0.14% of the total Nitrogen and is not a problem in the present invention. Boron-11 is present at 80.1% of the total Boron. In embodiments of the present invention, the electrode is prepared from Boron-10 to a 99% purity so that the electrons in the Boron have equivalent mobility to the electrons in Carbon and Nitrogen.
[0108] In embodiments of the invention as illustrated in
[0109] The Carbon-Carbon bond length is 0.14 nm in a sheet of Graphene, the same distance as the separation of the sheets of Carbon. However, the sigma bond between Carbon in the sheet of Graphene is significantly higher strength that the pi bond between layers. This allows the Disk to have a resonant response because the Disk is positioned in a cavity with freedom of vertical movement in the cavity formed by heavier bottom glass, which could for example be 3 mm thick, and the lighter top glass, which could for example be 0.2 mm thick.
[0110] A single hexagon with Carbon atoms located at the six (6) corners can measure 0.242 nm across. Therefore, there are 4010.sup.16 Graphene hexagons in the 66 surface that contain 24010.sup.16 Carbon atoms. The total number of Carbon atoms in the Disk that contains eight (8) sheets is 1910.sup.18 Carbons. These numbers show that each photon incident on the Graphene Carbon solar cell 20 has the opportunity on a path for absorption and conversion into one or more electrons by first impinging on a Carbon atom as is schematically shown in
[0111] The Graphene solar cell can operate at an estimated sixty percent (60%) efficiency, with incident 1.5 AM Suns (1,000 watts per square meter) calculated to produce 15 milliamps per square centimeter at four (4) Volts or fourteen (14) Watts for a six-inch (6)six-inch (6) cell. A solar panel 10 according to the invention of four (4) feet by six (6) feet could, for instance, contain seventy-two (72) cells and would produce a calculated 1,008 Watts or nominally one (1) Kilowatt. The same size Silicon solar panel produces 395 Watts. Embodiments of the present invention are thus estimated to produce 2.55 times the energy as the referenced prior art solar panels.
[0112] The 14-Watt cell at 4 volts produces 3.45 amps. Each amp per second is a Coulomb that contains 6.2410.sup.18 electrons or a total of 21.510.sup.18 electrons per second. The quantity of electrons required to be produced by the cell, 21.510.sup.18 electrons per second, approximately equals the number of Carbon atoms in the cell, 1910.sup.18 Carbons. The disclosed cell thus exceeds the one electron per photon production by Multiple Excitation Generation (MEG) producing as many as three (3) electrons per photon. Therefore, as few as one third of the Carbon atoms participate in the absorption of photons each second to produce the 14-Watt cell.
[0113] Embodiments of the Disk include what can be analogized as antennas or tuning forks that resonate to the range of frequencies of the photon of light to be absorbed and converted to electrons that are instantaneously collected and transmitted to the electrodes to produce useful power. The incident light eV is received by the Carbon's bandgap locations, and the eV of the light that exceeds the energy required to excite the electron in this band gap is split off and conducted to other of the Carbon's band gap locations to excite another electron. This process of releasing more than one electron for each photon of light that is absorbed is Multiple Excitation Generation (MEG), which increases the efficiency of the Graphene solar cell. Reference may be had to
[0114] A further beneficial characteristic of the present invention is that the Graphene Carbon has the ability of aggregating the lower energy photons in the red and infrared region to produce higher energy photons. The characteristic colors of violet, blue, green, and red are emitted when low energy infrared photons are incident on Carbon atoms held in the Graphene structure. This aggregation of energy into higher energy photons is another process by which the present invention increases the conversion efficiency of the incident solar energy.
[0115] Carbon has six electrons. The energy of the pairs of electrons in the orbit shell closest to the nucleus is low, which makes these electrons not available for elevation to the conductive band. The energy level of the next pair of electrons that have a higher energy are also not available since one electron spins in the opposite direction of the other electron and acts as a counter balance. The electrons in the 2p.sub.x and 2p.sub.z both spin in the same direction and are available to be elevated to the conductive band. As has been previously stated, the atomic number of Carbon of six makes Carbon more reactive and more likely to release an electron to the conductive band than Silicon, which has an atomic number of 14 with a larger nucleic mass holding its electron with more force.
[0116] As an alternative to hexagonal Boron Nitrogen (hBN), Graphene can be doped to produce Nitrogen atoms with strong electron donor capability at a greater concentration by contact with nitric acid. Exposure to the nitric acid can, for instance, be for longer than 10 minutes for eight layers or more with concentrated acid and Boron atoms, with strong electron withdrawing capability, such as by thermal annealing in the presence of Boron Oxide without a need for incorporating a catalyst.
[0117] In another preferred aspect of the invention, three hBN layers are incorporated that are located at the top, the bottom, and in the center. Thus, two Graphene Cubes with four layers each are separated by an hBN layer. The electrical connection of the hBN is such that the top Graphene layer in the n-type and the bottom layer in the p-typed doped and the hBN layers are connected. Accordingly, the two portions of the cell are in electrical series.
[0118] Because both Graphene and Boron Nitride have identical hexagonal structures, hBN or the individually doped Boron Carbon (BC) and Nitrogen Carbon (NC) have the same electron paths. This allows for electron export with a minimum distance from the point of absorption to export of the electron as is depicted in
[0119] Turning to
[0120] The superconductive paths in hBN are at 60 degrees chirality. This allows the use of hBN at both the top and bottom of the Graphene Disk with Nitrogen connected at the top to collect electrons without the interference of the Boron atoms and the reverse connection of the Boron atoms for electrons deficit without the interference of the Nitrogen atoms.
[0121] The Disk has multiple layers of Graphene. One or more Disks in the optical path defined by the Sun's illumination can be disposed at one end of the path and a reflective mirror can be disposed at the other end of the path. The number of layers of Graphene can be a multiple of two in each Disk, such as 2, 4, 6, or 8 layers, and the number of Disks connected in electrical and optical series can be a multiple of one, including 1, 2, 3, or 4. When more than one Disk is placed in series, the doping of the Graphene can be alternated starting with Nitrogen doping.
[0122] The Disk forms a plurality of Corner Reflecting Antennas with what can be analogized as rungs of a ladder where the rungs of the ladder are the Carbon-Carbon bonds of 0.246 nm. The spacing between layers of 0.335 nm allows harmonics of Solar Energy Frequencies to resonate with these antennas as illustrated in
[0123] For the Disk to achieve the design value power, 14 Watts or 2.1810.sup.19 electrons per second of production is required. The Disk, containing 4.410.sup.18 Carbon atoms, receives illumination of 0.6 Photons/second that make available a possible 1.8 electrons/second. Following the details and calculations of
[0124] A sequence of manufacture for solar cells as disclosed herein is depicted schematically in
[0125] The chart of
[0126] Practices of the invention can rely on plural wafer stacks 14 with Graphene. For instance, Graphene wafer stacks 14 can be constructed for use and testing hereunder with four (4) layers of Graphene oxide nanosheets (4-GON) and two (2) stacks of eight (8) layers of Graphene oxide nanosheets (8-GON) as is shown in
[0127] Testing is intended to confirm the desired number of layers in wave stacks and the preferred doping content of Nitrogen. The number of layers is confirmed by optical measurement at 550 nm wavelength and reported to confirm the number of layers of Graphene in the wave stacks. As set forth hereinabove, each layer is calculated to attenuate the Yellow-Green light by 2.6%. Therefore, the 4-GON layered Graphene will attenuate light by 10.4%, and the 8-GON layered Graphene will attenuate light by 20.8%. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), or Raman spectroscopy can be used to confirm the doping level to 16.7% with one Nitrogen replacing one of the six (6) Carbons in the hexagonal crystalline structure.
[0128] Further, practices of the invention can rely on hexagonal Boron Nitride (hBN). By way of example, testing can be performed with plural, such as ten (10), pieces of monolayer of three (3) forms, namely Types A, B and C, of hBN as depicted in
[0129] Testing can further be employed to confirm the desired number of layers in the Nitrogen and Boron content. For instance, SEM, TEM, or Raman spectroscopy may be used to confirm the composition of the hBN in terms of the number of Nitrogens replacing Borons or the number of Borons replacing Nitrogens in the hexagonal crystalline structure.
[0130] With respect to forming an electrode in the passivation layer for an electrical connection, the passivation layer can be etched to form a channel to contact the edge of the hBN to allow electrical connection of the hBN capped wafer stack as is depicted schematically in
[0131] Potential configurations for assembly of the wafer stack and the hBN can be further perceived by reference to
[0132] Still further, testing can be conducted to confirm desired spacing of the stacks 14. By way of example, SEM, TEM, or Raman spectroscopy can be used to confirm the consistency of spacing of the stacks 14. The spacing can, for example, be equal to a distance of 0.14 nm between hBN and Carbon layers and 0.14 nm between Carbon Layers.
[0133] Final assembly of a Type One wafer stack 14 with 4-GON Layers, and hBN Caps can be typical of plural types of wafer stacks 14. With additional reference to
[0134] a) The bottom glass is inserted into a 5 mm long Square Glass Tube (SGT), positioned at one end of the SGT, and fixed in place with epoxy;
[0135] b) The Type B hBN is thermally transferred to the bottom glass, positioned in the chemically-etched passivation layer to electrically connect through the Nanosilver/Graphene to form an anode connection for what can be referred to as a Trilogy Solar Cell; and
[0136] c) The top glass is positioned above the SGT that contains the bottom glass with the Wafer Stack attached with the distance between the two glass plates at 2.7 nm measured, maintained, and fixed in place, such as with epoxy.
[0137] With certain details and embodiments of the present invention for Systems and Methods for the Conversion of Solar Energy to Electric Power disclosed, it will be appreciated by one skilled in the art that numerous changes and additions could be made thereto without deviating from the spirit or scope of the invention. This is particularly true when one bears in mind that the presently preferred embodiments merely exemplify the broader invention revealed herein. Accordingly, it will be clear that those with major features of the invention in mind could craft embodiments that incorporate those major features while not incorporating all of the features included in the preferred embodiments.
[0138] Therefore, the claims that will ultimately be employed to protect this invention will define the scope of protection to be afforded to the inventor. Those claims shall be deemed to include equivalent constructions insofar as they do not depart from the spirit and scope of the invention. It must be further noted that a plurality of the following claims may express certain elements as means for performing a specific function, at times without the recital of structure or material. As the law demands, any such claims shall be construed to cover not only the corresponding structure and material expressly described in this specification but also all equivalents thereof.