CN107112379A - Solar energy aerial array and its manufacture - Google Patents

Abstract

A kind of solar energy aerial array can include capturing and converting sunlight into the aerial array of electric power.Cost is minimized for building the method for solar energy aerial array using template and autoregistration semiconductor processing steps.The visible ray and non-polarized light of wide spectrum can be captured with optimization design.It can also carry out from array test and disconnect defective antenna.

Description

Solar Antenna Array and Its Manufacture

Cross References to Related Applications

This application is a continuation-in-part of US Patent Application No. 13/454,155 filed April 24, 2012, which is incorporated herein by reference in its entirety.

technical field

Aspects of the present disclosure may relate to economical manufacturing processes for visible light rectenna arrays for converting solar energy into electricity.

Background technique

Rectifiers for alternating current (AC) to direct current (DC) conversion of high frequency signals have been known for decades. A specific type of diode rectifier known as a rectenna when coupled to an antenna has also been known for decades. More specifically, more than 20 years ago, Logan in US Patent 5,043,739, issued August 27, 1991, described the use of an array of rectennas to capture microwaves and convert the microwaves into electrical energy. However, the size of the antenna was limited by the frequency until recently when Gritz in US Patent 7,679,957 issued March 16, 2010 described the use of a similar structure to convert infrared light into electricity, and Pietro Sicilia Pietro Siciliano in "Nano-Rectenna For High Efficiency Direct Conversion of Sunlight to Electricity": IMM-CNR (Pietro Sici liano of The Institute of Microelectronics and Microsystems) For Microelectronics and Microsystems IMM-CNR), Pietro Siciliano, Lecce (Italy)" suggested that this structure could be used for sunlight.

However, the minimum size required for such visible light rectennas is usually in the tens of nanometers. While these dimensions can be achieved with today's deep submicron masking techniques, such processing is typically much more expensive than current solar cell processes that require larger dimensions.

However, as Logan pointed out in US Patent 5,043,739, microwave rectifiers can achieve efficiencies as high as 40%, twice that of typical single-junction polycrystalline silicon solar cell arrays, and when used as in Pietro The proposed metal-oxide-metal (MOM) rectifier diodes do not require semiconductor transistors in the core of the array.

Therefore, it may be advantageous to be able to take advantage of the existing fine geometry processing capabilities of today's semiconductor manufacturing without incurring such manufacturing costs.

And recently, Rice University announced that researchers have created a carbon nanotube (CNT) with metal-like electrical and thermal properties. In addition, single-walled carbon nanotube (SWCNT) structures are becoming increasingly manufacturable as described in US Patent 7,354,877, issued April 8, 2008 to Rosenberger et al. Various forms of continuous CNT growth are also contemplated, such as the continuously harvested CNT "forests" of Lemaire et al. Practice the technique described in US Patent 8,137,653 issued March 20, 2012 by Predtechensky et al. Grigorian et al. in US Patent 7,431,985, issued October 7, 2008, describe CNT growth by continuously pushing carbon gas through a catalyst-backed porous membrane.

In addition, others have considered using SWCNTs in various structures, such as Mike Williams on February 13, 2014 at http://news.rice.edu/2014/02/13/rices CNT wire from Rice University as described in "Rice's carbon nanotube fibers outperform copper" on carbon-nanotube-fibers-outperform-copper-2, Thailand Magnetic data storage as described in U.S. Patent 7,687,160, issued March 30, 2010 to Sen. Winarski, and in particular, U.S. Patent Publication 2010/ Antenna-based solar cells described in 0244656. However, Ito et al. do not describe a method for the low-cost construction of carbon nanotube solar antennas for efficient conversion of solar energy.

Contents of the invention

Embodiments of the invention may relate to structures and/or methods of fabricating rectenna arrays for converting sunlight into electricity that can be fabricated using self-aligned process steps and using current deep submicron IC masking techniques template to achieve the fine dimensions required by the antenna.

The structure of the antenna array can include a row of antennas connected to the positive and negative rails through MOM diodes. The antennas may be of equal length, centered for maximum reception of green light.

In one embodiment, the number of rows of antennas can be varied incrementally back and forth along the array between the optimally received portion of blue light and the optimally received portion of red light. This optimal receiving section can consist of a half-wavelength antenna whose length can vary from 220 to 340 nanometers. A rectenna array can be attached to a solid back, which can include mirrors to reflect light back into the array. It can also be used as a ground plane, where the distance between the ground and the antenna array and the dielectric constant of the polymer between them can form an ideal strip antenna for visible light.

In another embodiment, a pair of arrays can be sandwiched together such that the layers of the antenna are perpendicular to each other.

In one embodiment, the template can be created by a series of masked anisotropic V-groove etch followed by anti-stick deposition. The method steps include polishing the resist to allow non-grooved portions of the silicon to be etched by the V-shaped grooves.

In another embodiment, the template can be used in successive metal deposition steps to fabricate the rectenna array. When used as a deposition target, the template can be angled or flat, and the deposition can be much smaller than the depth of the V-grooves in the template. The resulting metal can be peeled off the template using a polymer backing material. Additional layers can then be deposited on the polymer-backed rectenna array.

In another embodiment, the template can be repeatedly cleaned and reused.

In another embodiment, the rectenna array may have redundant antennas that can be powered through the array to disconnect the antennas if defective.

In another embodiment, carbon nanotube antennas can be grown between metal wires consisting of a mixture of metal and metal oxide nanospheres formed from a V-groove template.

Description of drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

1 is a logic diagram of an antenna array according to an embodiment of the present invention,

Figures 2a, 2b and 2c are cross-sections in the Y direction of a template according to an embodiment of the invention during its manufacture,

Figures 3a, 3b, 3c and 3d are cross-sections in the X direction of a template according to an embodiment of the invention during its manufacture,

Figure 4 is a diagram of a portion of a template according to an embodiment of the present invention,

5a, 5b, 5c and 5d are cross-sections of an antenna array in the X direction according to an embodiment of the present invention,

6a, 6b and 6c are cross-sections along the Y direction of an antenna array according to an embodiment of the present invention during its manufacturing process,

Figure 7 is a cross-section of a portion of an antenna array according to an embodiment of the invention,

Figure 8 is a cross-section of two antenna arrays clamped together according to an embodiment of the present invention,

Figure 9 is a top view of a portion of an antenna array according to an embodiment of the present invention,

Fig. 10 is a top view of two antenna arrays clamped together according to an embodiment of the present invention,

11a and 11b are logic diagrams of an antenna array with defects before and after testing according to an embodiment of the present invention,

12a, 12b and 12c are cross-sections along the Y direction of a template according to an embodiment of the present invention during its manufacture,

Figures 13a, 13b, 13c and 13d are cross-sections in the X direction of a stencil according to an embodiment of the invention during its manufacture,

Figure 14 is a top cross-sectional view of a portion of a stencil according to an embodiment of the invention,

Figures 15a to 15f are cross-sections of an antenna array on a template during fabrication according to an embodiment of the invention,

Figures 16a, 16b and 16c are cross-sections of an antenna array according to an embodiment of the invention after it has been removed from the template during its manufacture,

Figure 17 is another logical diagram of an antenna array according to an embodiment of the present invention,

Figures 18a to 18d are cross-sections of another formwork fabrication according to an embodiment of the present invention,

Figures 19a and 19b are diagrams of parts of a template according to an embodiment of the invention,

Figures 20a to 20d are cross-sections of an antenna array according to an embodiment of the invention during its manufacture,

21a to 21d are cross-sections of an antenna array according to another embodiment of the present invention during its manufacture,

Figures 22a and 22b are top views of two different configurations of power and ground lines on a solar array corresponding to portions of the formwork shown in Figures 19a and 19b,

Figure 23 is a cross-section of an antenna array with defective carbon nanotube antennas,

Figure 24 is an annotated cross-section of an antenna array according to an embodiment of the invention, and

25 is a cross-section of an antenna array with a cover plate according to another embodiment of the present invention.

detailed description

Embodiments of the present invention are now described with reference to Figures 1-24, it being understood that the figures may be illustrative of the subject matter of various embodiments and may not be to scale or measure.

A logic diagram of one example of an embodiment of the present invention is shown in FIG. 1 . The core of a solar antenna array may have rows of antennas 10 separated by power lines 13 and ground lines 14 . The power line and the ground line are connected to the antenna by tunnel diodes 11 and 12, respectively. When the antenna is excited by visible light, current can flow from the ground line to the power line, producing half-rectified power. It will be understood by those skilled in the art that additional circuitry such as switches and decoupling capacitors may be included around the periphery of the solar antenna array which may be desired to generate stable DC power at a voltage suitable for commercial applications.

For antennas to efficiently receive visible light, it is beneficial for them to capture 1/4 or 1/2 the wavelength of the light, depending on whether the antenna is coupled to an existing ground plane. In order to produce such small structures without expensive masking operations, templates for the manufacture of antennas can be created.

Referring now to FIG. 4 , an example of a top view of one embodiment of such a template. The template may have rows of horizontal v-grooves 40 bounded on each side by a large ridge 41 and a small ridge 42 . The ridges may alternate across the antenna array. The template can be formed from a silicon wafer with a crystallographic orientation (1,1,1) to facilitate the production of V-shaped structures.

Referring now to Figures 2a, 2b and 2c, there are examples of cross-sections in the Y direction of the first set of steps that can be used to produce the formwork. Initially, the silicon wafer 21 of FIG. 2 a can be patterned with near minimum dimension lines in the positive resist, which can be etched vertically to create a series of small trenches 23 . These trenches may then have a layer of etch stop material 22, such as silicon oxide or silicon nitride, deposited over them. A similar pattern can be formed in the negative resist, where the similar pattern can consist of lines close to the minimum dimension, and an etch stop layer 24 can be deposited that can be equally spaced between the trenches 23 .

As shown in Figure 2b, in a next step, the resist line 24 and deposited material 22 can form an etch stop for the V-groove etch, which can remove a portion of the silicon wafer 25, leaving alternating large ridges 26 and Small ridge27. Then in Figure 2c, a thin etch-stop layer can be deposited over the entire array, which may adhere to non-(1,1,1) silicon surfaces. A subsequent vertical etch can be used to remove all the etch stop layer along the thin silicon layer 29 from the horizontal surfaces between the ridges 28 , leaving a thin etch stop layer deposited on the large and small ridges 28 . It should be noted that a combination of the alignment of the masking steps to form the trench 22 and resist line pattern 24 in FIG. 2a and the duration of the V-groove etch 25 in FIG. 2b can be used to produce a suitable antenna length 20, as shown in FIG. 2c Show.

Referring now to Figures 3a, 3b, 3c and 3d, there are examples of cross-sections in direction X of a second set of steps that may be used to produce the formwork. In Figure 3a, a regular array of equal width lines 30 and spaces can be patterned on a flat silicon surface between small and large V-shaped ridges (eg, can be prepared as discussed above). A subsequent partial V-groove etch may form a partial V-groove 31 between the resist lines 30 . If a (1,1,1) silicon material is used, this may not be a time critical step, since the etch may preferentially select the (1,1,1) silicon surface, stopping when the trench is complete. A thin layer of etch stop material can then be deposited in the etched V-groove 33 and removed by removing it with the resist used to pattern the V-groove 32, as shown in Figure 3b . Another V-group etch is performed using the material in the existing V-groove 35 as an etch stop, which can be used to etch the new V-groove 34, as shown in Figure 3c. The resulting groove pattern can then be cleaned of etch stop material and subsequently covered with a layer of material that does not adhere to the metal antenna, such as silicon nitride 36 as shown in Figure 3d.

The alignment of the lines 30 between the V-shaped ridges does not need to be precise, as long as they are large enough to extend over the V-shaped ridges without exceeding the V-shaped ridges, because the initial V-groove etch in Fig. 3c does not affect the small and material 28 on the large ridges, as shown in Figure 2c. Although it may be desirable to keep the lines 30 and spaces 31 to a minimum size as shown in FIG. 3a, it may not be critical; Depths are kept as equal as possible. Thus, in another embodiment, the V-groove etch in Figure 3b can be followed by resist removal and a continuous V-groove etch if the line spacing can be maintained to tighter tolerances than the line width and spacing, Thus producing as many halves of the V-groove as twice as deep. In this case, the trenches formed in the Y direction can be enlarged to ensure proper fabrication of the solar antenna array.

Solar antenna array templates can be made from part or all of silicon wafers. It is further contemplated that silicon ingots can be grown in the necessary orientation to be cut into long panels, or that monocrystalline silicon can be annealed on long panels of silicon deposited on glass or other suitable structures. It is further contemplated that the size of the template need only be determined by its ability to be reliably used and reused in the manufacture of solar antenna arrays.

Referring now to Figures 5a, 5b, 5c and 5d, an example of an X-direction cross-section of a first set of steps that may be used to fabricate a solar antenna array according to an embodiment of the present invention. Figure 5a shows the result of depositing a suitable conductive material onto the V-shaped grooves of the template 50, forming a wire 51 which may become an antenna. This can be achieved using eg low pressure chemical vapor deposition (LPCVD) equipment. In one embodiment, nickel can be used because it does not adhere to the silicon nitride template. In order to form a metal-oxide-metal (MOM) rectifier diode that can handle terahertz frequencies, the cross-section of material 51 can be formed with a 1/4 circle radius smaller than 40 nm, but the V-groove size can be much larger because the amount of material is determined by The deposition time rather than the size of the V-groove is determined. Forming a reasonable antenna array may require the use of a heated template, vibrating the template, or depositing metal on the template at an angle of up to 45 degrees, or any combination of these processes. A layer of polymer material 52, such as polyamide, may then be deposited on the template, as shown in Figure 5b, and may then be cured sufficiently to allow the polymer material 52 and wires 51 to detach from the template, as shown in Figure 5c. The peeling can be performed in the X direction perpendicular to the antenna to prevent damage during the peeling process. A thin oxide layer 53 may then be grown on the wire 51 as shown in FIG. 5d. The oxide layer at the end of the antenna may be thinner than 6nm.

Referring now to Figures 6a, 6b and 6c, there are examples of Y-direction cross-sections that can be used for the second set of steps in the manufacture of solar antenna arrays. As shown in Figure 6a, when the template is peeled off, the polymer material 52 can form a large depression 61 and a small 62 from the large V-shaped groove 41 and the small V-shaped groove 42 (as shown in Figure 4) on the template. sunken. To keep the antenna 53 insulated from subsequent metal deposition, a thin cover glass layer 60 may then be deposited over the antenna array. In one embodiment, a short etch may be added to ensure that the oxide on the end of the antenna 53 is exposed. Next, as shown in Figure 6b, a power line material 63 may be deposited and polished to remove extraneous material from the antenna array, leaving distinct power lines, as shown in Figure 6b. A sufficient amount of material can be deposited to fill the small concavities 62 but only partially fill the large recesses 61 . In another embodiment, a thin layer of non-adhesive material can be deposited/grown on top of the deposited material to allow easy removal of polishing debris and another short etch can be added after polishing to again secure the end of the antenna 53 The oxide on the is exposed. As shown in Figure 6c, ground line material 65 may be deposited and polished from portions of the array in a manner similar to the process for power lines to form ground lines, as shown in Figure 6d. In another embodiment, the power and ground wire materials may be malleable metals, such as aluminum and gold, respectively.

In another embodiment of the fabrication process, the template can be cleaned, repaired, and reused to fabricate multiple antenna arrays as needed.

It should be noted that the design of the template and associated antenna array process can be optimized to minimize the overall cost of the manufacturing process while maximizing template reuse and antenna array yield by minimizing the cost of the template and antenna array process.

In another embodiment of the template structure and antenna array process, the majority of the antenna array can be constructed on the template, and only polishing and applying a protective layer to the antenna array can then be done after removing it from the template.

Referring now to Figures 12a, b and c, examples of cross-sections in the Y direction of a template according to an embodiment of the present invention during its manufacture. In this case, as shown in FIG. 12b, the vertical side V-shaped groove 123 can be etched by masking the resist 120. First, as shown in FIG. V-groove 123 etching is shown. Resist may then be refilled into V-groove 125 and polished to expose silicon 124, as shown in Figure 12c. The resist can be used as an etch stop for the subsequent X-direction etch.

Referring now to Figures 13a, b, c and d, exemplary cross-sections in the X direction of a template according to one embodiment of the present invention during its manufacture. A masked resist pattern 130 can be formed, which can then be etched by the V-grooves, as shown in Figure 13a. The resist can then be reapplied and polished, leaving the resist in the existing V-grooves 132, and another V-groove etch can be performed, resulting in another set of V-grooves 133, as shown in Figure 13b . The resist can then be removed, as shown in Figure 13c, and a thin layer 134 of non-adhesive material can be applied to the template, as shown in Figure 13d. Unlike previous X-direction V-groove processes as shown in Figures 3a, b, c and d, the current process does not require the deposition of an etch stop layer or its subsequent stripping.

Referring now to FIG. 14 , a top cross-sectional view of an example of a formwork portion according to one embodiment of the present invention. In this case, although the antenna X-direction V-shaped grooves 140 may be substantially the same as those 40 shown in FIG. 4 , the V-shaped grooves 141 and 142 may be opposite to the V-shaped ridges 41 and 42 shown in FIG. 4 . This facilitates the deposition of power and ground lines on the formwork before the fabricated antenna array is removed from the formwork.

Reference is now made to Figures 15a-f, cross-sectional illustrations of an antenna array on a template during fabrication of an embodiment of the present invention. Initially, as shown in Figure 15a, a suitable conductive material such as nickel may be deposited onto the template to form the antenna 151, including the bottom of the trench 152, which may be followed by a thin oxide step. Next, as shown in Figure 15b, a cover glass 153 can be deposited, which can at least reach the top of the X-direction V-shaped groove. In one embodiment, a short etch may be added to ensure that the oxide on the end of the antenna 151 is exposed. Ideally, the underlying glass and conductive layers can be chosen not to adhere to the non-adhesive layer 134 on the template, as shown in Figure 13d. Optionally, in the next step, another thin layer 154 of non-adhesive material can be deposited if the conductive material for the power and ground lines is not easily removable from the existing non-adhesive layer, as shown in Figure 15c . Then, in the same manner as the process shown in Figures 6a, b and c, the conductive material for the power line 155 shown in Figure 15d and the ground line 156 shown in Figure 15e can be deposited and polished (as required) respectively. Then, as shown in Figure 15f, a flexible polymer 157 may be deposited to form a backing for peeling the antenna array from the template.

Referring now to FIG. 16a, a cross-sectional illustration of an antenna array with an added cover glass layer peeled from the template and flipped over, according to one embodiment of the present invention. Optionally, the thick cover glass can be polished to remove unnecessary layers to the power conductive material 162 and ground conductive material 161, as shown in Figure 16b, and additional passivation material 163 can be added to cover the exposed conductive material, as Figure 16c shows. It should be noted that the same materials and steps as described in the first process can be used in this fabrication process, and other fabrication steps can be added, or the steps described herein can be modified as needed to improve the yield of the antenna array, or to save the template .

Referring now to FIG. 7 , a Y cross-section of an example of a completed solar antenna array according to an embodiment of the present invention. In this case, a transparent cover layer 75 can be added to protect the array, and a solid backplane 74 can be attached to the polymer material 52 to make the structure more rigid. There may be a MOM diode 71 between the antenna 53 and the ground line 65 and a further MOM diode 72 may be present between the antenna 53 and the power line 63 due to the oxide grown on the antenna. In another embodiment, the back plate 74 may be a mirror for reflecting light not absorbed by the antenna array. In another embodiment, the backplane 74 can be a conductive ground plane, and the thickness of the polymer material 52 can be adjusted so that the antenna array can function as an optimal stripline antenna array.

Reference is now made to Figure 8, which reflects an example of another embodiment of the present invention. The solar antenna array 80 can optimally absorb light polarized along the antenna direction (eg, Y direction), which is generally only 1/2 the energy of sunlight. Other components of randomly polarized light from the sun, such as the X component, can be transmitted through or reflected from the solar antenna array. Thus, in another embodiment, two such solar antenna arrays 80 and 82 may be sandwiched together with a light rotating material 81, such as a liquid crystal disposed between them. Additionally, a layer 83 of reflective material may be attached to the back of the structure to reflect remaining light back into the interlayer array. It is further contemplated that polymeric material 52 and conductive ground backplane 74 as shown in FIG. 7 may be optically transparent and may be included in such a sandwich structure.

In another embodiment of the invention, the material 81 may be optically transparent and the two solar antenna arrays 101 and 102 as shown in FIG.

Referring now to FIG. 9 , a top view of a portion of an example solar antenna array in accordance with an embodiment of the present invention. While the highest energy in visible light is typically in the blue-green portion of the spectrum (wavelength around 500 nm), it is desirable to absorb as much of the visible spectrum as possible. Therefore, it is desirable to vary the antenna length to cover most of the visible spectrum, for example from 400nm to 720nm. This can be accomplished by changing the dimensions of the respective rows of antennas going back and forth across the array, going from two 1/4 wavelength sections of 100nm each 92 up to two 1/4 wavelength sections of 180nm or if not adding The ground plane is twice these dimensions. The graph 90 in FIG. 9 can be used to cover the spectrum from 400nm to 720nm in eight equal steps, although there are finer variations in the step size and more steps may occur before repeating, so that the prism can be used to Light of the appropriate frequency is directed to the most receptive antenna.

Those skilled in the art will appreciate that the dimensions described in this disclosure may be difficult to manufacture and may be prone to defects, particularly open circuits (“open circuits”) and/or short circuits (“short circuits”) between the antenna and power or ground lines. ")middle.

Referring now to FIG. 11 a , a diagram of a portion of an example of an antenna array according to an embodiment of the present invention, wherein the antenna array is shown with bad diodes depicted as resistors randomly connecting the antennas to the power supply 112 Or ground 113. In some cases, antenna 111 may have two shorted diodes. This defect can create a short or partial short between the power and ground wires.

In another embodiment, the antenna array can be tested and fixed by applying a voltage between the ground and power lines sufficient to force a single tunnel diode beyond its negative resistance but not sufficient to conduct on a good pair of diodes. This selectively drives current through a shorted defective diode, heating the resistor sufficiently to open the short in a manner similar to a fuse, so that the short between power and ground can be removed,

Reference is now made to FIG. 11 b , a schematic diagram of a portion of an example of an antenna array according to an embodiment of the present invention, wherein the antenna array is shown with a defective diode that is fused and depicted as an open circuit capacitor 115 , thereby randomizing the antenna elements. Connect to power supply 112 or ground 113 . In an antenna with two shorted diodes 114, the weakest of the resistors may fuse 116, eliminating the short.

In another embodiment, the antenna elements may be spaced close enough to each other to minimize degradation in power production through the array due to the elimination of random defective antennas.

In another embodiment of the present invention, the antenna may consist of carbon nanotubes grown between the power line and the ground line. In this case, the template can consist essentially of V-shaped grooves of the same depth.

Reference is now made to Figures 18a to 18d for cross-sections of examples of formwork fabrication. A regular width pattern can be exposed to the resist 181 and a short vertical plasma etch can be performed followed by a subsequent V-groove etch leaving a first set of V-grooves between the remaining resist 180. Alternatively, a phosphorous doped wafer can be used to construct the template, and a selective nitrogen doping diffusion 188 can be performed on the initial V-groove. Thereafter, the cleaned wafer may be coated with a thin layer of non-adhesive material such as silicon nitride (SiN) or silicon carbide (SiC), coating the first set of V-grooves 183 and the top surface of the wafer, as shown in FIG. 18b Show. After polishing the wafer to remove the non-adhesive material on the unetched surface 182, the second set of V-grooves 184 are etched, leaving the first set 185 protected by the non-adhesive material, as shown in Figure 18c. Finally, an additional layer of non-stick material can be added to the wafer, covering all of the V-grooves 186, as shown in Figure 18d. The first set of V-shaped grooves 187 may be etched wider than the second set of V-shaped grooves to compensate for the different thicknesses of the non-bonded material.

Alternatively, different non-adhesive materials such as silicon nitride and silicon carbide may be deposited in the first set of V-shaped grooves 185 and in the second set of V-shaped grooves 184, respectively. The template formed comprises power 190 and ground 192 V-groove fingers, each connected in interconnected fashion to power 191 and ground 193 V-groove strips, with alternating breaks 194 and 195 at the other end of the fingers, as Figure 19A shows. It is also conceivable that the V-groove fingers for the power lines 196 and ground lines 197 can be varied horizontally and vertically, as shown in Figure 19b

Reference is now made to Figures 20a to 2Od, cross-sections of examples of an antenna array according to an embodiment of the present invention during its manufacture. Initially, a carbon nanotube catalyst such as iron, nickel, or some other magnetic metal can be arc-sputtered onto the stencil, forming a layer of small optional oxide spheres in the V-shaped grooves. A conductor such as gold, silver, aluminum or some other suitable metal or alloy can be deposited in the V-shaped groove so that the catalytic ball 201 can hang over the edge of the conductor 202, as shown in Figure 20a. Alternatively, a PN diode created between two sets of V-shaped grooves in the template is reverse biased, which can selectively deposit carbon nanotube catalyst in some of the V-shaped grooves 207 . A polymer 203 such as polyamide or some other suitable material can then be coated on the template as shown in Figure 20b. After curing the polymer 203, the entire structure can be removed from the template. Optionally, the oxide balls 205 may be etched back, thereby exposing the metal of the catalytic balls, as shown in Figure 20c. Thereafter, the power and ground wires can be heated and charged to negative and positive voltages respectively, an optional magnetic field can be applied, and hydrocarbons such as methane or acetylene can be introduced into the deposition chamber to grow between the power and ground wires carbon nanotubes, as shown in Figure 20d. Nanotubes can grow from catalytic spheres on the negatively charged electric field line to the metal on the positively charged ground line 208 . After the nanotubes are attached to the conductor, the conductor can be heated, which anneals the carbon nanotubes into a conductive material.

Reference is now made to Figures 21a to 21d, cross-sections of examples of an antenna array according to another embodiment of the present invention during its manufacture. In this embodiment, as shown in Fig. 21a, the V-grooves may only be filled with conductors 211 covered by polymer 212 and removed from the template. The power line and the ground line can be charged to negative and positive voltages, respectively, and the charged oxidized catalytic balls can be selectively deposited on the ground line 213 so that the power line 214 is away from the catalytic balls, as shown in Figure 21b. Thereafter, optionally, the exposed oxide may be etched away from the catalytic ball 215, as shown in Figure 21c. Subsequently, the carbon nanotubes 218 can grow from the ground line towards the opposite direction of the metal on the power line, and the catalytic balls are supported on the tips of the carbon nanotubes, so that the shortest carbon nanotubes 217 can be connected first, and the longer carbon nanotubes Tube 218 can be connected later, as shown in Figure 21d. The conductor, catalytic spheres and thin oxide can form a metal oxide metal (MOM) diode. In this way, as shown in FIG. 17, the rectifying MOM diode 171 can be connected to the power line 173 and the antenna 170, and the other end of the antenna 172 can be connected to the ground line. The diameter of the catalytic sphere can determine the diameter of the nanotube, the structure or chirality of the carbon nanotube can be determined in part by the applied magnetic field, and the growth direction of the nanotube can be determined by the electric field between the electric force line and the ground line, Its connection is performed continuously in the order of its length, as shown in Fig. 21d.

Referring now to FIG. 24, an annotated cross-section of an example antenna array of one embodiment of the present invention. The efficiency with which an antenna absorbs electromagnetic frequencies may decrease significantly the farther the electromagnetic frequency is from the antenna's ideal frequency, or the farther the electromagnetic wave is from the antenna. These effects significantly limit the efficiency of regular two-dimensional antenna arrays with different lengths. To absorb the optimal amount of visible and infrared solar energy, the antenna needs to vary in length between 80 nanometers and 460 nanometers. The nanotubes can be grown to a distance between 80 nanometers and 460 nanometers in the direction of an electric field that can be applied between the conductors containing the catalytic spheres. The amount of growth is related to the strength of the electric field and the density of the catalytic spheres, which can be chosen to maximize the efficiency of the resulting antenna. The power and ground lines of a solar antenna array can be constructed by depositing ~190 nm of catalytic spheres and metal 241 followed by ~40 nm of insulating polymer 242 using a template with V-shaped grooves that can be fabricated using inexpensive Masks with ~1/2 micron dimensions are constructed and may be coated with silicon nitride, silicon carbide, and/or some other material that does not adhere to the deposited conductor. Due to the coating and any optional etching, the resulting power and ground lines may be ~20 nm shallower than the original etched V-groove 240 .

Referring now to Figures 22a and 22b, top views of two different configurations of power and ground wires on a solar array corresponding to the template sections shown in Figures 19a and 19b. In either configuration, the array is limited to the size of the aligned V-grooves because conductivity requires the height of the power and ground lines to remain the same throughout the array. In one configuration shown in Figure 22a, the array may consist of alternating fingers of power lines 220 and ground lines 221, with vertical strands 222 and 223 and possibly multiple strands 224 and 225 as required, This keeps current density and resistance low. In another configuration, the array can contain a varying pattern of fingers of power lines 226 and ground lines 227 that can locally balance the horizontal and vertical directions of the nanotube antennas, as shown in Figure 22b. This configuration can eliminate the need for two vertically aligned panels clipped together.

It is also contemplated that the probe pads and larger wires may be deposited separately on the array prior to the initial charging of the power and ground wires.

Furthermore, it is contemplated that the conductor may be silver, aluminum, platinum, or another alloy that may be oxidized in the same process step as or adjacent to that of oxidizing the catalytic balls. Carbon nanotubes are then grown between the power line and the ground line and then a MOM diode can be formed between the power line and the end of the carbon nanotube antenna, and a carbon metal oxide metal diode between the ground line and the other end of the carbon nanotube antenna Similar to the structure shown in Figure 1.

It is also conceivable that the method of testing and fusing the short circuit shown in Figures 11a and b could be applied to carbon nanotube antennas, thereby disconnecting at least one end of a defective antenna. Referring now to FIG. 23 , a cross-section of an example of an antenna array with defective carbon nanotube antennas. After building the solar antenna array, some individual nanotubes may not be fully or incorrectly connected to the power line 230 and/or the ground line 231 . They can be tested and corrected using the following steps:

A: Turn the solar array upside down,

B. Ground both the power line and the ground line,

C. moving the positively charged power source under and across the antenna array such that the loose nanotubes are pulled behind the side of the power line or ground line to which they are attached, thereby destroying the freedom of the nanotubes, and

D. Remove any loose nanotubes that disrupt the array.

In another embodiment of the invention, a larger structure can support a cover plate over the array to protect the antennas, power lines, and ground lines from the external environment. Referring now to FIG. 25 , a cross-section of an example of an antenna array with a cover plate. Large plate lines 251 can be formed from polyamide by etching large V-shaped grooves on the outside of the template. It is also possible to periodically etch large squares of V-shaped grooves in the template, which can create a regular array of large polyamide cones or posts 252 between the power and ground lines 253 on the antenna array 250 on which the A supporting clear glass (or other material transparent enough to allow light through) plate 254 is placed to protect the antenna array. Optionally, if the polyamide is sufficiently transparent, the glass plate can be replaced by a mirror that can reflect light that might enter the array through the polyamide back to the antenna.

Those skilled in the art can understand that the present invention is not limited by the contents specifically exemplified and described above. Rather, the scope of the present invention includes combinations and sub-combinations of the various features described above as well as modifications and variations that would occur to those skilled in the art upon reading the foregoing description and which do not belong to the prior art.

Claims (20)

1. A solar antenna array configured to convert sunlight into electricity, comprising: evenly horizontally spaced alternating power and ground wires having sloped sides, and A carbon nanotube antenna whose length varies vertically, and the carbon nanotube antenna is connected between the power line and the ground line. 2. The solar antenna array of claim 1, wherein the power and ground lines further comprise conductive metal. 3. The solar antenna array of claim 2, wherein the conductive metal comprises at least one selected from the group consisting of gold, silver, platinum, copper and aluminum. 4. The solar antenna array of claim 2, wherein said power lines and ground lines further comprise catalytic balls. 5. The solar antenna array of claim 3, wherein the catalytic spheres comprise an oxide-coated magnetically conductive metal. 6. The solar antenna array of claim 5, wherein said conductive catalytic spheres comprise at least one material selected from the group consisting of nickel, iron and cobalt. 7. The solar antenna array of claim 1, wherein the antennas of different lengths are configured to cover at least two regions of the spectrum. 8. The solar antenna array of claim 1 wherein said antennas of different lengths are locally aligned in at least two directions. 9. The solar antenna array of claim 8, wherein the two directions are perpendicular to each other. 10. A method of building a solar antenna array, characterized in that the method comprises: Create templates on silicon wafers, depositing metal and insulating polymer layers on said template, separating the array from the template, grow carbon nanotubes between the catalytic spheres and the oppositely charged wires of the metal, and Defective carbon nanotubes are removed. 11. The method of claim 10, wherein creating a template comprises: exposing the pattern of lines in the resist coated on the silicon wafer, performing a first V-groove etch on the pattern of lines to obtain a first V-groove, coating the first V-groove with silicon nitride, removal of silicon nitride from the unetched surface of the silicon wafer, performing a second V-groove etch on the unetched surface to obtain one or more second V-grooves, and A second layer of the wafer is coated with at least one of silicon nitride or silicon carbide. 12. The method of claim 11, wherein the silicon wafer is a phosphorous doped silicon wafer, and wherein the first V-groove etch includes nitrogen doped diffusion. 13. The method of claim 11, wherein the coated first and second V-shaped grooves have a common width. 14. The method of claim 10, wherein applying the metallic and insulating polymer layers comprises: Conductive metals are deposited using low-pressure chemical vapor deposition (LPCVD), Simultaneous arc sputtering and oxidation of catalytic metal spheres, and Deposit insulating polymer. 15. The method of claim 10, wherein depositing metal and insulating polymer layers comprises: A voltage is applied across the nitrogen-doped diffused and phosphorous-doped silicon wafers to reverse bias the PN diodes. Conductive metals are deposited using low-pressure chemical vapor deposition (LPCVD), simultaneously selectively arc sputtering and oxidizing catalytic metal balls on one of said first V-groove and second V-groove, and Deposit insulating polymer. 16. The method of claim 10, wherein growing carbon nanotubes comprises: Applying a negative voltage on the power line, and a positive voltage on the ground line, heating power lines, filling the chamber containing the solar cells with hydrocarbon gas, and Continue to apply negative and positive voltages, heat the power lines, and fill the chamber until carbon nanotubes grow between the power and ground lines. 17. The method of claim 10, wherein depositing metal and insulating polymer layers comprises: Deposit conductive metals using low-pressure chemical vapor deposition (LPCVD), and Deposit insulating polymer. 18. The method of claim 17, wherein growing carbon nanotubes comprises: Applying a negative voltage on the power line, and a positive voltage on the ground line, selectively depositing charged oxidation catalytic spheres on said electric lines, etching oxide from the exposed surfaces of the catalytic spheres and conductive metal, heating power lines, filling the chamber containing the solar cells with hydrocarbon gas, and Etching the oxide, heating the power line, and filling the chamber continues until carbon nanotubes grow between the power and ground lines. 19. The method of claim 17, wherein growing carbon nanotubes comprises: Applying a negative voltage on the power line, and a positive voltage on the ground line, selectively depositing charged oxidation catalytic spheres on said electric lines, heating power lines, filling the chamber containing the solar cells with hydrocarbon gas, and Continue heating the power line and filling the chamber until carbon nanotubes grow between the power line and ground. 20. The method of claim 10, wherein removing defective carbon nanotubes comprises: heating the ground wire to anneal the carbon nanotubes to the metal, Flip the solar array over, Ground the power and ground wires, Disconnect one or more loose carbon nanotubes by moving a positively charged power source from one side of the wire containing the one or more loose carbon nanotubes towards the opposite side of the wire through the array in a direction perpendicular to the power and ground lines nanotubes, and The resulting one or more disconnected loose carbon nanotubes are removed.