Lens systems for solar energy solutions

Abstract

An integrated solar lens and lens system that may be active, a hybrid, or a self-powered system. A solar lens is fabricated and configured to concentrate received solar energy onto a solar sensor material, whereby a medium is provided between the lens and the solar sensor material, such as a fluid and a fluid including micro or nano components including transparent microemulsion balls, and ionized particles. Such balls and particles improve the transducing of the solar energy to heat, and which heated fluid can be circulated throughout a system.

Description

CLAIM OF PRIORITY

This application claims priority of U.S. Provisional Application Ser. No. 61/128,113 filed May 19, 2008 entitled FULLY INTEGRATED LIGHT VALVE the teachings of which are included herein.

FIELD OF THE INVENTION

The present invention is generally related to solar cells and systems, and more particularly to solutions for capturing and converting solar energy, and circulation of such collected energy.

BACKGROUND OF THE INVENTION

Solar energy is typically collected by solar cells, which solar cells operate as a transducer to convert solar energy into electricity, heat, or some other energy medium. For instance, solar cells may comprise of p-n semiconductor junctions which are configured to emit electrons as electrical energy when bombarded with solar energy. This electrical energy is in the form of electrical current, and is conventionally accumulated in battery cells to store such created energy.

Over the years, a variety of solar cell technologies have been designed with the goal of providing a low cost, highly efficient mechanism that is practical for use in a variety of applications. Some would argue the near term goal is to meet the performance level of producing one Watt of energy for every dollar of solar cell material, commonly referenced to as the buck-a-watt goal.

One such known solar technology developed in the 1990's is the spheral solar cell technology developed by Texas Instruments Corporation of Dallas, Texas. An array of silicon spheral balls were created and doped to create a plurality of p-n junction cells arranged in an array, resembling an egg crate structure. These solid spheral balls were typically comprised of fused silicon powder or particles, doped and etched to create a p-n junction.

Other solar cell solutions include solar ribbons, such as those developed by Seimens Corporation.

There is a continued need to achieve more efficient solar energy transducers at an affordable cost.

SUMMARY OF INVENTION

The present invention achieves technical advantages as an integrated solar lens and lens system that may be active, a hybrid, or a self-powered system. A solar lens is fabricated and configured to absorb energy within the structure of the lense, and concentrate received solar energy, such as onto a solar sensor material, whereby a medium is provided between the lens and the solar sensor material, such as a fluid that may contain micro or nano components including transparent microemulsion balls, and ionized particles. Such balls and particles improve the transducing of the solar energy to heat or charge solutions, and which heated or charged fluid can be efficiently circulated throughout a system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a diagram of a fluid-filled lens configured to direct received solar energy to a solar sensor material;

FIG. 2-7 show a method forming a lens using molds;

FIG. 8 is a first design showing the lens of FIG. 7 including a first absorption layer plus dichroic layer created on the lens, and a second absorption layer below the sensor;

FIG. 9 is a second design showing the lens of FIG. 9 including a first absorption layer and an antireflective layer created on the lens, along with a second absorption layer below the sensor;

FIG. 10 shows a third design including a first absorption layer and a reflective layer formed upon the lens of FIG. 7;

FIGS. 11-13 shows a top down orientation option for the lens of FIG. 8;

FIG. 14 shows an integrated lense, fluid and electrostatic stage systems into an active scanning example; and

FIGS. 15-94 depict additional preferred embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, there is generally shown at 10 a solar cell seen to include a spheral lens 12 configured to absorb, direct and/or focus received solar light 14 to a solar sensor material 16. The lens 12 is configured over a chamber 18 formed within a frame 20, this frame 20 being sealed to a substrate 22 via a hermetic solder ring seal 24. This chamber 18 is filled with a fluid, and which fluid may include transparent microemulsion balls 30, semiconductor materials, and/or ionized particles. These balls are extremely small, and may have diameters ranging from one micron to one millimeter, although limitations to these dimensions is not to be inferred as nano and micro balls/particles are contemplated, as well the shapes of these particles may not be spherical but oblong, or have other symmetry for a cavity design, and thickness to absorb light, and have a uniform coating or doping around its surface. These balls and/or ionized particles are configured to efficiently transduce light to heat, charge the balls or particles, or both. These balls and particles may also be circulated to transmit heat from the substrate, and through a system. These balls and particles can also be used to create battery-like storage and charge transfer. The charged solution can be circulated to increase the charge in solution and aid in the active surface area that can be drawn from.

The balls or particles 30 may comprise of TiO2 powder, silicon, multiband semiconductor balls, quantum dots, ionic charge particles, or other particles, and may, if desired, have an antireflective coating, such as aluminum, or a graded antireflective coating. Energy not collected in the lenses and its antireflective coating. Ideally the graded coating is preferred to match the liquid/ball filled interior with an index matching filled media, or of a greater index to focus the light with different demagnification to a low cost matched optical focused area sensor at the base of the interior of the system. This sensor can be optional and the entire base can be reflective in the range of wavelengths that are passed through the lense into the media. The same base outside of the sensor should be reflective for the range of light passing through the lense to increase the energy absorption of the particles/balls in the media. The aformentioned types of particles with a greater density offer the ability to tune the lens to liquid index matching. Those particles/balls with a combinational semiconducting nature and ionic nature will allow for a battery charge flow to occur. Those particle/balls solutions with graded or other antireflective coating allow for resonance or charge creation to create heat. This heat in turn heats the liquid medium and creates a flow through the tube to circulate the collected heat to areas where this energy is used to create steam from water.

FIG. 2 shows the first of several steps for forming an integrated solar lens. Step A is shown in FIG. 2 and depicts a semispherical shaped mold 40 comprised of a p-layer having a semispherical recess 42. This semispherical recess 42 may be formed by an isotropic etch (such as dry, wet, plasma, ash, etc) into the p-substrate layer 40. This layer 40 may be coated, printed, liftoff, doped, implant/cleave, etc. Optionally, the p-layer can be etched using a non-isotropic process, which can be done for non-semispherical shaped molds.

FIG. 3 depicts Step B which comprises a front side implant or diffusion of n-doped material into the p-type base layer 40 to create an n-layer 44 along the surface of the substrate 40 and along the curved surface 42 as shown. This n-layer prevents release of layers and release of top film. This n-layer 44 can also be used for multiband base layer that will be doped into.

Step C depicts an n-substrate 50 with a recess 52, similar to the process shown in FIGS. 2 and 3, whereby a p-layer 54 is formed on top of the n-layer 50 from front side doping. Optionally, a multiband doping maybe provided to protect from back side release wet etchs.

FIG. 4 depicts multiple options and steps that can be performed, these options include:

• • 1) diochroic+transparent top electric p contact coat
  • 2) antireflective layer+top p contact coat, antireflective+transparent top p contact, top p contact, antireflective+p contact layer
  • 3) reflective layer+top p contact electrode, reflective top p contact layer

FIG. 5 depicts Step E, whereby after Step D shown in FIG. 4, the mold is filed in for strength with a material, with either a transparent polymer/polymide, silicon, a hybrid layer, ceraset, oxide, etc, and then planarized as shown.

FIG. 6 shows Step F where the back side layer 40 layer is released. Thereafter, optional process paths may be performed including:

• • 1) Opt for diffractive circular grating
  • 2) Opt for IR antennas
  • 3) Opt for n-type antireflective or reflective contact layer
  • 4) As applicable, lens can be integrated into arrays, passive, self-powered, and actively powered stages.

FIG. 8 shows a Step G according to a first design whereby a second sensor layer 60 is attached and includes a sensor 62 positioned proximate a focal point of the lens structure formed and generally shown at 64. An optional transparent top coat may be provided for physical strength and reliability. FIG. 8 shows a first design whereby the resulting structure includes a first absorption layer, a dichroic layer and lens. A second lower cost absorption layer may be provided for tuned wavelengths. As shown in FIG. 8, incident solar light directed on the lens assembly is configured such that a desired colored light is passed, focused and directed through layer 48 onto sensor 62. Non-desired colored light is reflected from the lens structure as shown.

FIG. 9 depicts a second design for Step G whereby the lens structure is provided with a first absorption layer and an antireflective coating upon the lens. In this embodiment the received full spectrum of incident light on the lens structure is allowed to be directed upon sensor 62.

FIG. 10 depicts a third design for Step G, where a first absorption layer and a reflective layer is disposed upon the lens structure. The optional transparent top coat can be applied to all designs for physical strength and reliability if desired.

Turning now to FIG. 11-13, there is shown an additional three steps for the first design of FIG. 8 that may be provided in a top down orientation. Shown in FIG. 11 is Step H, whereby a top coat is applied for structural fill and strength to complete the following processing stages.

Shown in Step I in FIG. 12 is selective removal of the material filling the lense cavity.

Shown in Step J of FIG. 13 is the completed top down design. The lense is designed and manufactured upside down to the std process. The advantage is to allow a second structurally strong but transparent (or etched through light path around the sensor) wafer to be bonded to the tense backing. This aids in alignment for the attaching of these two substrates. As well the local regions on the top of the handle wafer can be then etched bringing direct path of the light down into the back side of the lense. In this scenario the micro lense acts both as a focusing reflector and an absorber of light. Additionally the handle wafer offers environmental protection to the system from external weather, integrated into the design.

FIG. 14 shows an integrated lense, fluid and electrostatic stage systems into an active scanning example and to compare the advantages. It is to replace the large and expensive tracking systems used in solar systems today and to optimize peak sun light tracking from sunrise to sunset. Usually large and expensive tracking stations are used to tilt mirrors or lenses all day long to optimize the amount of light into the system as compared to the height of the sun across the day sky. This system is also used for raster scanning of the absorbing device (balls, substrates, etc below). The idea here is to minimize all wasted energy. Usually in the art people dump so much energy into the sensor that it turns to wasted heat. The device then can never overcome this limitation and begins to become less and less efficient the higher the energy flux and thermal heat it creates. By raster scanning the device you put a time domain transfer rate into this action so that just the right amount of energy to maximize the device is put in, but not so much that the device is running super hot and starts become less and less efficient. This is a core element to the active tracking invention. Allowing it to achieve in concentrated environments higher efficiencies. Further the addition of the liquid media and solar balls in the lense designs allows for super fluid flow rates designs to be implemented that not only absorb solar energy but regulate heat in the system. This energy that is absorbed into the balls and the liquid allows for then other work to be done and collected from the solution for heating water or the like to generate electricity. In the charge solution design versus thermal transducing balls this allows the full solution to be circulated and constantly kept charged getting around limitations of diffusion and making possible a very large surface area battery design for maximum current draw in minimal space.

TECHNICAL ADVANTAGES

The lense itself absorbs energy, whatever is not absorbed inside the shell of the lense, or the outer coating of the lense, is focused or reflected onto either a second transducer or the particle(shapes) in solution, or the particle(shapes) and a 2^nd transducer. The design is meant to couple a hybrid solution for collecting energy between semi materials, resonance heating, and/or charge collection, or both. The designs unique vertical hybrid coupling of several methods of solar transducing allow the vertical stack of transducing methods to be tunneable given each system (lense coating, balls(shapes), non covered wavelength sensor) optimally as a set to have different ways to optimize them independent of the other, grabbing more energy than they can separately. In addition for the fluid filled cases, and the active staging designs the 2^nd sensor, which normally, is thermally limited from achieving optimum solar cell efficiency can be kept cool and the input energy can be rastered at a maximum rate. In theory vertical wall space can also be used in a 3d design to pack more charge/heat creation capability into the design since the rastering lense can move the light around on a wide angle. This allows for fluid vs the 2^nd sensor to be heating multi channels of different transducing, thermal conductivity, charge to be energized or waveguided away to do other work and not wasted as is done in macro systems. Finally the lense on the stage in this design as well gets rid of the need of tracking Thus a gymboled lense system will track passively (gymboled arms are charged as light hits diode on their support structures versus shadowed sides don't receive as much energy causing a miss balance in charge creation on the arms. This difference of voltage then in opposition to the electrodes below the lense stage have an electrostic force that will realign the stage until the voltage ratios (ie optimal angle to get the maximum energy into the lense) are balanced in the gymboling arms. As the sun moves across the sky the gymboled lense rebalanced the pull of the charged diode designs above with the electrostatic bars below automatically. This prevents the need for programming and complex electronics. Else if needed and more complicated tracking is need the electrodes and the gymboling can be actively energized to tilt and move the lense around to optimize energy transfer.

FIGS. 15-94 depict additional preferred embodiments of the invention.

Though the invention has been described with respect to a specific preferred embodiment, many variations and modifications will become apparent to those skilled in the art upon reading the present application. The intention is therefore that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.

Claims

1. A solar cell, comprising:

a first layer comprised of a first semiconductor material and having a recess;

a second layer comprised of a second semiconductor material and forming a lens portion over the recess and a cavity therebetween; and

a fluid disposed in the cavity.

2. The solar cell as specified in claim 1 wherein the first material and the second material form a p-n semiconductor junction.

3. The solar cell as specified in claim 2 wherein the fluid is a liquid.

4. The solar cell as specified in claim 3 further comprising particles disposed in the fluid.

5. The solar cell as specified in claim 4 wherein the particles are configured to absorb solar energy transmitted thereto through the lens portion.

6. The solar cell as specified in claim 4 wherein the particles are configured to reflect solar energy transmitted thereto through the lens portion.

7. The solar cell as specified in claim 4 wherein the particles comprise balls.

8. The solar cell as specified in claim 7 wherein the balls are microemulsion balls.

9. The solar cell as specified in claim 7 wherein the balls have a coating.

10. The solar cell as specified in claim 7 wherein the balls are configured to absorb solar energy transmitted thereto through the lens portion.

11. The solar cell as specified in claim 9 wherein the balls have a reflective coating.

12. The solar cell as specified in claim 9 wherein the balls have an antireflective coating.

13. The solar cell as specified in claim 7 wherein the balls have substantially the same diameter.

14. The solar cell as specified in claim 4 wherein the particles are configured to be ionized.

15. The solar cell as specified in claim 4 further comprising a sensor configured under the lens and configured to react to received solar light as a function of the particles.

16. The solar cell as specified in claim 15 wherein the particles are configured to improve the function of the sensor.

17. The solar cell as specified in claim 4 wherein the second layer is also disposed upon a portion of the first layer.

18. The solar cell as specified in claim 4 wherein the lens has a coating configured to absorb solar energy.

19. The solar cell as specified in claim 4 wherein the lens has a coating configured to reflect solar energy.

20. The solar cell as specified in claim 4 wherein the lens has a dichroic layer.