MXPA00001759A - Reflective concentrating solar cell assembly - Google Patents

Abstract

A solar cell assembly for focusing incident radiation on a solar cell. The assembly comprises a reflective member having first and second opposite surfaces. The first surface is transparent to allow incident radiation to pass into the reflective member. The second surface has a plurality of reflective portions positioned to receive the radiation and reflect and focus the radiation toward the first surface. The radiation strikes the first surface at an angle greater than a critical angle of the first surface and is reflected and focused back toward the second surface. The assembly further comprises a solar cell positioned at least proximate to the reflective member to receive the radiation reflected and focused from the first surface of the reflective member and generate electric current from the radiation.

Description

ASSEMBLY OF SOLAR CELLS OF REFLECTIVE CONCENTRATION TECHNICAL FIELD The present invention relates to assemblies of solar cells, and more particularly to an assembly of solar cells of reflecting concentration. BACKGROUND OF THE INVENTION Photovoltaic solar cells are used to generate electricity from the impact of radiation, such as solar radiation. Solar cells are usually formed from semiconductors, such as silicon, amorphous silicon, cadmium telluride, gallium arsenide, and copper and indium diselinide. When subjected to shocking radiation, the cells comprised of the above semiconductor materials generate an electric current. A problem with semiconductor solar cells is that the materials comprising the solar cells are usually expensive. As a result it is difficult to generate electricity with solar cells at a price that competes with electricity generated by other means, such as hydroelectric power or the combustion of fossil fuels. An approach to reduce the costs of semiconductor solar cells has been to make the cells extremely thin, thus reducing the amount of material required to form each cell. Another method to improve the i -. The efficiency of semiconductor solar cells has been to use refractive lenses to focus the radiation on the cell, thereby reducing the surface area of the cell required to receive a given amount of radiation. This method and the associated device are disclosed in U.S. Patent No. 5,437,736 to Cole. A drawback with the conventional methods and devices described above, is that the lenses used to focus the input radiation are usually bulky and non-uniform, resulting in assemblies of solar cells that are difficult to handle, and that collect dirt and other debris, thus reducing the efficiency of the solar cells. A further drawback of the devices described above is that the separate semiconductor solar cells must be electrically coupled to generate sufficient electrical current for typical applications. The electrical coupling of the separate solar cells requires the use of additional materials and process steps, thus increasing the cost of solar cell assembly. One approach to solving the above drawbacks has been to use reflection instead of refraction to direct the incident radiation towards the solar cells. U.S. Patent No. 5,288,337 to itchell discloses a photovoltaic module having a concave bottom surface that directs radiation by total internal reflection to adjacent solar cells. U.S. Patent No. 4,235,643 to Amick, and U.S. Patent No. 4,313,023 to Stephens disclose facets directing radiation by total internal reflection to a set of circular solar cells. U.S. Patent No. 4,162,928 to Shepard, Jr., discloses a plate having a regular pattern of uniform indentations that reflect radiation to a solar cell. United States Patent Number 3,973,994 to Redfield discloses a solar cell having a grooved lower surface that reflects radiation by the total internal reflection back and forth between the upper and lower surfaces of the solar cell. A drawback of the above devices and methods is that they do not collect the incident radiation or direct the radiation to the solar cells in an efficient manner. In accordance with the foregoing, the above methods and devices require a relatively large solar cell surface area to receive a given amount of incident radiation. COMPENDIUM OF THE INVENTION The present invention incorporates a method and apparatus for reflexively focusing radiation on solar cells. An assembly of solar cells under one embodiment of the invention, includes a reflective member having first and second opposing surfaces. The first surface is at least partially transparent, and the second surface has a plurality of reflective portions positioned to receive radiation passing through the first surface of the reflective member, and to focus and reflect the radiation to form focused radiation. The focused radiation is directed towards the first surface at an angle relative to the first surface greater than a critical angle of the first surface. The first surface is placed to direct the focused radiation away from it, such that the focused radiation converges as it moves away from the first surface. The assembly further comprises a solar cell positioned at least close to the reflecting member. The solar cell has a radiation receiving surface positioned to receive focused focused radiation away from the first surface of the reflective member, and generate an electric current therefrom. In another embodiment of the invention, the reflective member comprises a support layer having first and second opposing surfaces, the first surface of the reflective member comprising the second surface of the support layer. The reflective member further comprises a film layer having first and second opposing surfaces, the first surface of the film layer being secured to the first surface of the support layer. The second surface of the reflective member comprises the second surface of the film layer. Each reflecting portion of the reflective member includes a reflective metallic layer positioned to direct a portion of the radiation focused through the film layer, and through the support layer, to the second surface of the support layer, without impacting another portion. reflective In another embodiment of the invention, the solar cell is a first solar cell, the plurality of reflective portions is a first plurality, the radiation comprises a first portion of radiation, and the focused radiation beam is a first portion of focused radiation. The assembly further comprises a second plurality of reflective portions that are positioned to receive a second portion of radiation passing through the first surface of the reflective member. The second reflective portions focus and reflect the second portion of radiation to form a second portion of focused radiation directed toward the first surface, at an angle relative to the first surface, greater than a critical angle thereof. The first surface is positioned to direct the second portion of focused radiation away from the first surface by the total internal reflection, such that the radiation of the second portion of focused radiation converges as it dies away from the first surface. A second solar cell is placed at least close to the reflective member to receive the second portion of focused radiation. In still another embodiment of the invention, the solar cell of the assembly is a first solar cell, and the radiation comprises a first portion of radiation. The assembly also comprises second, third, and fourth solar cells. The plurality of reflective portions includes a first reflective portion positioned to reflect the first portion of radiation toward the first solar cell, and a second reflective portion that faces the first reflective portion, and positioned to reflect a second portion of radiation toward the second. solar cell. The assembly further comprises a third reflective portion positioned intermediate the first and second reflective portions, to reflect a third portion of radiation towards the third solar cell, and a fourth reflective portion positioned opposite the third reflective portion, to reflect the fourth portion of radiation to the fourth solar cell. The first, second, third, and fourth reflective portions each have a triangular shape, and are joined at a common point to form a pyramidal reflective element.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view of an assembly of solar cells in accordance with one embodiment of the present invention. Figure 2 is a top plan view of the solar cell assembly shown in Figure 1. Figure 3 is an illustration of a computer generated ray tracing calculation for an assembly of solar cells in accordance with the embodiment of the Figure 1. Figure 4 is a side elevational view of a first alternative embodiment of the solar cell assembly shown in Figure 1, wherein a thickness of a reflective member comprising the assembly is selected to focus the incoming radiation by a selected amount . Figure 5 is a side elevational view of a second alternative embodiment of the solar cell assembly shown in Figure 1, wherein the film layer comprising the reflective member has an inverted orientation. Figure 6 is a side elevational view of a third alternative embodiment of the solar cell assembly, wherein a layer of film comprising the reflective member includes two conductive layers. Figure 7 is a side elevational view of a fourth alternative embodiment of a solar cell assembly in accordance with the present invention, wherein a reflective member of the assembly comprises a single member. Figure 8 is a plan view of a portion of a fifth alternative embodiment of an assembly of solar cells having a two-dimensional pattern of solar cells. Figure 9 is an amplified isometric view of a portion of the solar cell assembly shown in Figure 8. Figure 10 is an isometric amplified view of an alternative embodiment of the two-dimensional solar cell assembly shown in Figure 8. Figure 11 is an amplified isometric view of another alternative embodiment of the two-dimensional solar cell assembly shown in Figure 8. Figure 12 is a plan view of a sixth alternative embodiment of an assembly of solar cells in accordance with the present invention, having solar cells circular, and a concentrically configured reflective portion. Figure 13A is a side elevational view of an alternative embodiment of the solar cell shown in Figure 1. Figure 13B is a side elevational view of another alternative embodiment of the solar cell shown in Figure 1.

Figure 13C is a side elevational view of yet another alternative embodiment of the solar cell shown in Figure 1. Figure 13D is an isometric view of yet another alternative embodiment of the solar cell shown in Figure 1.

DETAILED DESCRIPTION OF THE INVENTION The high cost element of all photovoltaic energy systems remains of the conversion panels or photovoltaic modules or cells. Current industry standards include modules made from single-crystal silicon wafers. Photovoltaic energy systems that use silicon modules generate electricity at costs much higher than the costs associated with fossil fuel energy sources. The high price of these modules is directly related to the high cost of single-crystal silicon. To reduce costs, silicon must be used better, or it must be replaced with a lower cost alternative. To date, two separate technological approaches have been developed to solve the cost problem: concentration and thin-film materials. The concentration reduces the cost of the material by replacing mirrors and lenses to focus the incoming radiation. An example refractive approach is disclosed by U.S. Patent No. 5,437,736 to Cole, incorporated herein by reference. The focused radiation can be absorbed by a solar cell that has less surface area than a similar cell placed to absorb unfocused radiation. Through the approach of the incoming radiation, the amount of solar cell area required to receive the radiation is reduced, thereby reducing the total amount of solar cell material required. Thin film materials absorb sunlight, but they are only 1/50 the thickness of silicon wafers. This represents a significant saving in the volume of the material, and therefore in the material costs. The semiconductors shown include amorphous silicon, cadmium telluride, and copper and indium diselinide. Thin film materials are manufactured using any number of known vacuum deposition techniques, including chemical vapor, sputtering, and coevaporation. The modules are usually formed on glass sheets or thin and flexible substrates, where an interconnection of cells in series is handled as a part of the process. Unfortunately, these materials are inefficient to collect solar radiation, and therefore, require large surface areas, and therefore, higher material costs for an adequate generation of solar energy. iLi., The present invention solves several inherent problems with both the concentration and the thin film materials. Because the thin film materials are the starting material, the cost of the material is low, and high levels of concentration are not needed to further reduce the material costs of the cells. By using a low level of concentration, approximately 5x, approximately 1/5 thin material is required to achieve the same efficiency as a system with no concentration. The concentration is achieved in the embodiments of the present invention by the reflecting approach of the radiation to the thin film solar cell. Herein an assembly of solar cells is described in detail, and in particular, an apparatus and method for directing the incident radiation by the total internal reflection towards a solar cell. In the following description, numerous specific details are stipulated, such as specific materials, specific geometrical relationships, etc., in order to provide a complete understanding of the present invention. One skilled in the pertinent art, however, will recognize that the present invention can be practiced without one or more of the specific details, or with other geometric relationships, methods, and so on. In other cases, well-known structures or operations are not shown in detail, in order to avoid obscuring the present invention. Figure 1 is a side view of one embodiment of a solar cell assembly 20 in accordance with aspects of the present invention. Figure 2 is a top plan view of the solar cell assembly 20 shown in Figure 1. With reference to Figures 1 and 2, the solar cell assembly 20 comprises a plurality of solar cells 22 attached to a reflective member 24. In one embodiment, the reflective member 24 comprises a thin and flexible lower film layer 26, to which the solar cells 22 are attached, and an upper support layer 28 that adds structural support to the film layer 26. The incident radiation 30, shown schematically on the dotted lines in Figure 1, passes through the support layer 28 and the film layer 26, and is reflected internally and focused towards the solar cells 22, as described in more detail more ahead. The incident radiation 30 may comprise visible or non-visible radiation, depending on the characteristics of the solar cells 22 on which the radiation is focused. Through the approach of the incident radiation 30, the assembly of solar cells 20 can increase the efficiency with which the solar cells 22 convert the radiation to electric current, and can reduce the size of the solar cells necessary to convert a given amount of radiation . For purposes of illustration, only a portion of the total incident radiation is shown on the assembly of solar cells 20 in Figure 1. The support layer 28 includes a top surface 32 facing incident radiation 30, and an opposite lower surface 34. Support layer 28 is transparent to allow incident radiation 30 to pass therethrough. In one embodiment, the support layer 28 has a thickness TI of approximately 4 millimeters, and is at least partially rigid to support the film layer 26, as well as to substantially prevent the film layer from flexing. By substantially preventing the film layer 26 from flexing, the possibility of the solar cells 22 separating from the film layer is greatly reduced, and the reflective properties of the assembly 20 remain substantially fixed. The support layer 28 may comprise glass or acrylic, or may comprise other substantially transparent and rigid materials in alternative embodiments. The support layer 28 is joined with an adhesive layer 36 to the film layer 26. The film layer 26 is placed to reflect the incident radiation 30 by the total internal reflection., as discussed in more detail later. The film layer 26 has an upper surface 38 facing the support layer 28, and a lower surface 40 that faces away from the upper surface 38. The adhesive layer 36 is placed between the upper surface 38 of the film layer 26. and the lower surface 34 of the support layer 28, for bonding the support layer to the film layer. In one embodiment, the film layer 26 comprises a shaped or molded acrylic thimble, and may comprise other transparent materials in other embodiments. In one embodiment, the film layer 26 has a thickness t2 of 0.5 millimeters, and other embodiments have film layers with larger or smaller thicknesses, as described below. The adhesive layer 36 may be transparent to allow incident radiation 30 to pass from the support layer 28 to the film layer 26. In one embodiment, the refractive indices of the support layer 28, the adhesive layer 36, and the film layer 26, are approximately equal, to reduce the possibility of radiation being reflected at any of the interfaces between the backing layer, the adhesive layer, and the film layer. The lower surface 40 of the film layer 26 includes a plurality of separate transparent regions 42. The solar cells 22 are bonded or otherwise secured to the transparent regions 42, to receive the light that passes through the film layer. 26, and generate electric current from it. In the embodiment shown in Figures 1 and 2, the solar cells 22 are elongated and are spaced parallel to one another below the transparent regions 42. The solar cells 22 are preferably linked to the transparent regions 42 by adhesive tapes 46. The adhesive tapes 46 can have a refractive index identical to, or almost identical to, a refractive index of the film layer 26, to reduce the possibility of reflection of the interface therebetween. The opaque regions 44 are placed on the lower surface 40 of the film layer 26, between each transparent region 42. In an exemplary embodiment, the opaque regions 44 are rendered opaque by the presence of a reflective layer 48 covering the lower surface 40 in its opaque regions. The reflective layer 48 may comprise metallic materials or other reflective materials. As best seen in Figure 1, the opaque regions 44 are configured to form a series of alternating first mirror portions 50 that are tilted down from left to right, and second mirror portions 52 adjacent thereto, which are tilted downwardly. from right to left. The reflecting portions 50 and 52 form reflective facets on the lower surface 40 of the film layer 26, which reflect the incident radiation 30 towards the solar cells 22, as discussed below. The first reflective portions 50 are oriented to receive and reflect the first radiation portions 54. The first radiation portions 54 pass through the support layer 28 and the film layer 36, and are reflected by the first reflection portions 50 of return to the upper surface 32 of the support layer 28, forming first portions of reflected radiation 56. The first reflective portions 50 are oriented to direct the first portions of reflected radiation 56 towards each other, thereby focusing the first portions of radiation reflected as they approach the upper surface 32 of the support layer 28. The first reflective portions 50 are also positioned in such a manner that the first reflected radiation portions 56 impact the upper surface 32 by more than the critical angle of the surface higher. As used herein, the critical angle refers to the minimum angle at which the radiation that is passing from a first medium to a second medium is reflected at the boundary between the medium returning to the first medium. The internal reflection refers to the resulting reflection. In accordance with the above, the first portions of reflected radiation 56 are reflected by the total internal reflection on the upper surface 32, forming first portions of redirected radiation 58, which are directed towards a first solar cell 22a. The second reflective portions 52 are placed between each first reflective portion 50. The second reflective portions 52 are positioned to receive the second radiation portions 60, and reflect the second radiation portions towards the upper surface 32 of the support layer 28, forming second portions of reflected radiation 62. On the upper surface 32, the second portions of reflected radiation 62 are redirected by the total internal reflection to a second solar cell 22b, forming second portions of redirected radiation 64. In one embodiment, the first adjacent reflective portions 50 are inclined towards each other. Accordingly, the first portions of reflected radiation 56 are at least partially focused as they approach the upper surface 32 of the support layer 28. The upper surface 32 reflects the first portions of reflected radiation 56, as such. so that the first portions of redirected radiation continue to converge and focus as they move away from the upper surface towards the first solar cell 22a. In a similar manner, the second adjacent reflective portions 52 can be tilted towards each other to focus the second portions of reflected radiation 62. In the embodiment shown in Figures 1 and 2, six first mirror portions 50 and six second portions are placed. reflective 52 between each solar cell 22 for purposes of illustration. In other embodiments, a greater or lesser number of reflective portions may be placed between the solar cells 22, as will be shown in Figure 3. In a further aspect of the embodiment shown in Figures 1 and 2, the first and second reflective portions. 50 and 52 are positioned and oriented in such a manner that the radiation reflected from the first reflective portions 50 does not impact the second reflective portions 52, and vice versa. In accordance with the foregoing, the first and second reflection portions 50 and 52 do not create shadows or otherwise block the radiation that passes to the solar cells 22a and 22b, respectively. As shown in Figure 1, the first reflective portions 50 have an angle a ^ with respect to the upper surface 32 of the supporting layer 28, and the second reflective portions have an angle a ^ with respect to the upper surface. The first and second solar cells 22a and 22b are separated by a distance d, and the solar cells 22 are separated from the upper surface 32 of the support layer by a distance t, comprising t- ^, the thickness of the layer of support 28, and t2, the thickness of the film layer 26. The angles a- ^ ya ^, the distance d and the thickness t, are related by the following two equations: d = 2 tl tan 90o-2a- (1) The above equations can be solved simultaneously to determine a ^ as a function of a - ^ _, to produce the following equation: a 2 = l / 2 \ 90 -atan 1/2 tan \ 90 ° - 2 ?!] (3) Then we can solve equation (3) to produce a range of values for a ^ corresponding to a range of values for Oi- ^. The minimum value for a- ^ is half the critical angle in the upper surface 32. The critical angle is an angle dependent on the material for the internal reflection, which is approximately 42 ° for the acrylic. Substituting the resulting ranges in equations (1) and (2), it is found that the separation distance d is 1.8t to 2.22t for a reflective member 24 having a critical angle of 42 °. For other materials that have higher refractive indexes, the range can be extended up to 1.Ot to 2.22t. Figure 3 is an illustration of a computer generated ray tracing calculation, based on the above equations, and assuming a critical angle of 42 °. As seen in Figure 3, the first and second reflective portions reflect the incoming radiation 30 to impact the first and second solar cells 22a and 22b. The radiation reflected in the reflective layer 48 passes unobstructed to the upper surface 32 of the reflecting member 24, and back to the solar cells 22a and 22b. In one embodiment, the solar cells 22 are thin film solar cells, comprising a thin film portion 66 mounted on a substrate 68, as shown in Figure 1. The thin film portion 66 includes a radiation receiving surface 70. which receives the incoming radiation in the form of direct radiation portions 71, and portions of reflected radiation as described above. In alternative embodiments, the solar cells 22 comprise solar cells different from the thin film solar cells, which are also capable of receiving the incident radiation and generating an electric current therefrom. These alternative modalities may require adjustment of the separation of the solar cells and angles of the reflecting portions. In the further alternative embodiments, the solar cells 22 do not need to be fixed directly to the film layer 26, but rather can be placed close to a surface of the reflective member 24, provided that the radiation that passes out of the reflective member and towards the solar cells is not at an angle that is less than the critical angle of the surface of the relevant reflective member. In accordance with the above, the radiation passes out through the relevant surface of the reflecting member 24 to the solar cells 22, instead of being reflected inside the reflecting member. In still another alternative mode, the solar cells 22 are fixed directly to the lower surface 34 of the support layer 28. In this alternative embodiment, the film layer 26 comprises a plurality of strips attached to the lower surface 34 between the solar cells. 22, instead of being a single continuous sheet. According to the above, the strips may extend parallel to each other between the solar cells 22, to form assemblies of solar cells having a wide range of overall widths. This alternative embodiment is convenient, because it allows to manufacture assemblies of solar cells 20 that are not limited in size by the width of the film layer 26. In one embodiment, the adjacent solar cells 22 can be electrically coupled by the connection of the thin film portion 66 and the substrate 68 of each solar cell to the reflecting layer 48 with conductive contacts 72. Accordingly, the reflective layer 48 may comprise an electrically conductive material. The reflective layer 48 has gaps in the transparent regions 42, such that the current is routed in series through each solar cell 22. Other circuit configurations are used in other embodiments. The conductive contacts 72 may comprise continuous conductive protrusions, as best seen in the plan view of Figure 2, or alternatively, may comprise intermittent protruding portions (not shown). The conductive contacts 72 are formed by welding or other conductive materials known to those skilled in the art, which electrically couple the adjacent solar cells 22 by the reflective Ccipa 48 placed between each pair of solar cells. Accordingly, the reflecting layer 48, which serves to reflect and focus the incident radiation, serves the dual purpose of electrically coupling the solar cells 22, which would otherwise require a separate parasitic element for electrical coupling. In one embodiment, a layer of backing material 74 may be placed against the reflecting layer 48 and the solar cells 22. The backing material layer 74 protects the solar cells 22 and the reflective layer 48 from incidental contact with potentially harmful objects. during shipment and installation of the solar cell assembly 20. The backup material 74 may comprise an elastic material, which can be easily bonded to the solar cells 22 and the reflective layer 48. In one embodiment, the solar cells 22 and the backing material 74 may comprise an integral structure that adhesively bonds to the film layer 26 with the adhesive strips 46. Additional adhesive may be used to adhere the backing material to the reflective layer 48.

An advantage of one embodiment of the solar cell assembly 20 shown in Figures 1 and 2 is that the first and second mirror portions 50 and 52 are oriented to focus the incident radiation on the first and second solar cells 22a and 22b, respectively. In accordance with the foregoing, the size of the first and second solar cells 22a and 22b can be reduced, reducing the amount of normally expensive solar cell material required to receive a given amount of incident radiation. An additional advantage of one embodiment of the solar cell assembly 20 is that the upper surface 32 of the support layer 28 redirects the reflected radiation portions 56 and 62 in the form of redirected radiation portions 58 and 64, which continue focusing as they approach solar cells 22a and 22b, respectively. The additional concentration of the reflected radiation portions is carried out with a flat upper surface 32, instead of a contoured upper surface. Accordingly, still a further advantage of one embodiment of the solar cell assembly 20 is that the flat upper surface 32, unlike a contoured upper surface, does not tend to collect dust, dirt, and other contaminants that block the incident radiation and reduce the effectiveness of the assembly of solar cells. In addition, any dust or debris that may be collected incidentally on the upper surface of the ~~ - - ^ ^ S * ^ * ^ ^ cell, it is more easily removed from a flat upper surface than from a contoured upper surface. Yet a further advantage of one embodiment of the solar cell assembly 20 shown in Figures 1 and 2 is that the reflective layer 48 serves the dual purpose of reflecting and focusing the incident radiation on the solar cells 20, while at the same time providing an electrical coupling between the solar cells. The reflective layer 48, therefore, eliminates the need for any additional electrical coupling between the solar cells 22. Figure 4 is a side elevational view of a first alternative embodiment of the solar cell assembly 20 shown in Figures 1 and 2. The assembly of solar cells 20 shown in Figure 4 is substantially similar to the assembly of solar cells shown in Figures 1 and 2, and the elements of Figure 4 in the other drawings for the other alternative embodiments, will be similarly numbered when they are of a similar construction. Only differences in construction will be described in detail. As shown in Figure 4, a thickness t ^ 'of the supporting layer 28a is reduced relative to a thickness t ^ of the supporting layer 28 shown in Figure 1. As a result, the first and second portions of reflected radiation 56a and 64a, are less focused by the time they reach the upper surface 32 than the corresponding first and second reflected radiation portions 56 and 62 shown in Figure 1. In accordance with the foregoing, the first and second portions of Redirected radiation 58a and 64a also fail to focus sharply when they reach the first and second solar cells 22a and 22b, respectively. The thickness t -] _ 'of the support layer 28a can be selected in a deliberate manner to focus the incident radiation less sharply on the solar cells 22a and 22b, when compared to the support layers 28 shown in Figure 1. An advantage of the solar cell assembly 20 shown in Figure 4 is that the thickness of the support layer 28a can be selected to focus the incident radiation 30 by a desired amount. This capability is convenient, because it may be desirable to focus the incident radiation less clearly in some cases than in others. For example, when mounting the solar assembly 20 on a tracking mechanism to track the movement of the sun during the day, it may be convenient to focus the radiation on the solar cells a little less precisely, to take into account the inaccuracies of the tracking mechanism. According to the above, if the tracking mechanism does not accurately track the movement of the sun, at least a portion of the incident radiation will still impact the solar cell 22, despite the inaccuracies of the tracking. when the solar assembly can be placed consistently in relation to the incident radiation 30, it may be desirable to sharply focus the incident radiation, as shown in Figures 1 to 3, to reduce the amount of solar cell material required to collect a given amount. of radiation. Figure 5 is a side elevational view of a second alternative embodiment of an assembly of solar cells 20 having an inverted film layer 26, as compared to the film layer shown in Figures 1 and 2. For clarity purposes, the radiation shown schematically in Figure 1 has been removed from Figure 5; however, the assembly of solar cells 20 shown in Figure 5 operates in substantially the same manner as the assembly shown in Figure 1, as discussed below. As shown in Figure 5, the film layer 26 is placed adjacent the support layer 28, such that the reflective layer 48 is adjacent to the lower surface 34 of the support layer. The film layer 26 is bonded to the support layer 28 with the adhesive layer 38. As shown in Figure 5, the adhesive layer 38 completely fills any voids between the reflective layer 48 and the bottom surface 34, to reduce the potential of any reflection at the interface between the film layer 26 and the support layer 28. The solar cells 22a and 22b are placed between the opaque regions 44, to receive the reflected radiation from the first and second reflection portions 50 and 52, respectively . In one embodiment, the reflective layer 48 is electrically conductive, and the solar cells are electrically coupled to the reflective layer with wires or tabs 72a. In another embodiment, the substrate 68 of the solar cell 22 can be linked directly to the reflective layer 48 of a link site 72b. In other embodiments, other connecting elements may be used to couple the solar cells 22 to the reflective layer 48. Figure 6 is a side elevational view of a third alternative embodiment of an assembly of solar cells 20 having an inverted film layer. 26. The solar cell assembly 20 shown in Figure 6 is similar to the assembly shown in Figure 5, with the exception that the solar cells 22 are placed external to the film layer 26, instead of being sandwiched between the layer film layer and support layer 28. The film layer 26 shown in Figure 6, according to the above, includes a conductive layer 73, opposite the reflecting layer 48, to which the solar cells 22 are electrically coupled. a manner similar to that discussed above with reference to Figures 1 and 2. The backing material 74 can be provided to protect the solar cells 22, and as described above, integral can be formed mind with the solar cells. An advantage of the solar cell assemblies 20 shown in Figures 5 and 6 is that the radiation incident on the assemblies does not pass through the film layer 26, but rather is immediately reflected upon impact of the film layer. In accordance with the above, the film layer 26 need not comprise materials having highly refined optical characteristics, and instead may comprise cheaper materials, reducing the overall cost of the assembly of solar cells. Figure 7 is a side elevational view of a fourth alternative embodiment of a solar cell assembly in accordance with the present invention. As shown in Figure 7, the reflective member 24a comprises a single unit, rather than a composite of a support layer and a film layer. The reflective member 24a may comprise acrylic, glass, or other transparent rigid materials that are relatively inexpensive, and which have refractive indices that allow the reflective member 24a to reflect, focus, and redirect the incident radiation in a substantially similar manner to that discussed above with reference to Figures 1 and 2. The first and second reflective portions 50 and 52 are preferably machined on the lower surface 40 of the reflective member 24a, or the reflective member can be emptied or molded with the directly formed reflecting portions. on its lower surface. The solar cells 22 and the reflective layer 48 are then linked to the lower surface 40 in a manner substantially similar to that discussed above with respect to Figures 1 and 2. An advantage of the solar cell assembly 20 shown in Figure 7, compare with the assembly shown in Figures 1 and 2, is that the reflecting member 24a comprises a single unit. The reflective member of a single unit 24a, in accordance with the above, reduces the number of manufacturing steps required to form the reflective member, and reduces the potential for undesirable reflections at the interfaces between the components comprising the reflective member. Conversely, an advantage of the solar cell assembly 20 shown in Figures 1 and 2, when compared to the assembly shown in Figure 7, is that it may be cheaper to form the reflecting portions 50 and 52 in a thin film layer 26 of what it is to machine or otherwise form the reflecting portions directly on the reflecting member 24a. Figure 8 is a plan view of a portion of a fifth embodiment of a solar cell assembly 20a, having a two-dimensional pattern of solar cells 22. Figure 9 is an amplified isometric view of a portion of the solar cell assembly 20a shown in Figure 8. Referring to Figures 8 and 9, the solar cell assembly 20a comprises a reflective member 24b. For purposes of illustration the reflective member 24b is shown as a single unit, of a construction similar to that of the reflecting member 24a shown in Figure 7. In other embodiments, the reflective member 24b may comprise a composite of a support layer and a film layer, in a manner similar to that shown in Figures 1 and 2. The reflective member 24b includes a plurality of reflective elements 73. Each reflective element 73 has a 4-sided pyramidal shape that extends upwards, having first and second reflective portions 50a and 52a, and third and fourth reflecting portions 74 and 76. The first and second mirror portions 50a and 52a are positioned to reflect the incident radiation, by the total internal reflection, towards the first and second solar cells 22a and 22b, respectively. The incident radiation impacting the first and second reflection portions 50a and 52a is reflected on the upper surface 32 of the reflecting member 24b towards the respective solar cells 22a and 22b. In a similar manner, the incident radiation impacting the third and fourth mirror portions 74 and 76 is directed by the total internal reflection towards the third and fourth solar cells, 22c and 22d, respectively. For purposes of clarity, the electrical connections between the solar cells 22 in Figures 7 and 8 are not shown.; however, the solar cells can be electrically coupled using any of the previously discussed methods.

The first reflecting portions 50a of the adjacent reflective elements 73, are inclined towards each other, to focus the incident radiation on the solar cell 22a, in a manner similar to that discussed above with reference to Figures 1 and 2. In a way similarly, the second reflective portions 52a of the adjacent reflector elements 73 are also inclined towards each other to focus the incident radiation towards the second solar cell 22b. In a similar manner, the third reflective portions 74 of the adjacent reflective elements 73 are inclined towards each other to focus the incident radiation towards the third solar cell 22c, and the fourth reflective portions 76 of the adjacent reflective portions 73 are inclined one towards the other to focus the incident radiation on the fourth solar cell 22d. In addition, each reflective portion is oriented to direct the incident radiation to the respective solar cell without causing the radiation to impact a neighboring reflecting portion. The interference or shadow by the neighboring reflecting portions, according to the above, can be eliminated, increasing the efficiency of the assembly of solar cells 20b. In a preferred embodiment, the groups of solar cells, each comprising first, second, third, and fourth solar cells 22a-d, are diagonally staggered with respect to each other, such that only the corners of the cells are actually adjacent to each other. adjacent solar In accordance with the foregoing, each solar cell 22 receives radiation from four directions. Accordingly, an advantage of the solar cell assembly 20a shown in Figure 6, when compared to the assembly 20 shown in Figure 1, is that the solar cells 22 shown in Figure 6 can have twice the efficiency of the cells Solar cells shown in Figure 1, which receive radiation from only two directions. The amount of solar cell material required to receive a given amount of incident radiation, according to the foregoing, can be halved. In an alternative embodiment (not shown), the adjacent cells are not staggered, so that each adjacent cell shares one side with its neighbor. Adjacent solar cells 22 form a grid of rows and columns, separated by reflector elements 73. In this alternative embodiment, each solar cell receives radiation from only two directions, in substantially the same manner as described above with respect to FIGS. and 2. The collection efficiency for this alternative mode, according to the above, is equal to the collection efficiency for the solar cells shown in Figures 1 and 2, and half the efficiency for the solar cells shown in the Figures 8 and 9.

Figure 10 is an isometric amplified view of an alternative embodiment of the two-dimensional solar assembly 20a, shown in Figure 7. Each reflective element 73 of the reflective member 24b comprises a plurality of reflective subelements 73a. Each subelement 73a includes first, second, third, and fourth mirror portions 50a, 52a, 74, and 76, respectively, which reflect the incident radiation to the respective solar cells in a manner similar to that described above with reference to FIGS. 8 and 9. An advantage of the reflector subelements 73a shown in Figure 8 is that they can more precisely focus the incident radiation by individually focusing smaller portions of incident radiation, compared to the portions of radiation focused by the reflector elements 73 shown. in Figures 8 and 9. Figure 11 is an isometric amplified view of a portion of another alternative embodiment of the two-dimensional solar cell assembly 20a, having curved reflector elements 73b. Each reflector element 73b has a four-sided pyramid shape, but the sides of the reflector element comprising the reflective portions 50a, 52a, 74, and 76 are curved instead of flat. The curved shape may be concave, as shown in Figure 11, or convex in an alternative embodiment. Accordingly, an advantage of the reflector elements 73b is that the curved shape of the reflecting portions can further focus the radiation reflected by the reflective elements. By increasing the degree to which the incident radiation is focused, the amount of solar cell material required to receive a given amount of incident radiation can be further reduced, and the overall thickness of the solar cell assembly 20a can also be reduced. As shown in Figures 8 to 11, the reflective elements 73 have four-sided pyramidal shapes. In alternative embodiments, the reflective elements may have other shapes, such as six-sided hexagonal shapes. In these embodiments, the solar cells 22 have corresponding hexagonal shapes, and can be configured in relation to the reflective elements 73 in a staggered manner similar to that shown in Figure 8. In the additional alternative embodiments, the solar cells can have other shapes . In one of these alternative embodiments shown in Figure 12, the solar cell assembly includes circular solar cells 22e. The first and second reflection portions 50b and 52b surround in an alternating and concentric manner each solar cell 22e. The first and second reflective portions 50b and 52b, the spacing between the solar cells 22e, and the thickness of the reflective member 24 containing the first and second mirror portions, are all selected to reflect, focus, and redirect the incident radiation from the reflecting portions to the upper surface 32 of the reflecting member, and back to the solar cells 22e, in a manner substantially the same as that discussed above with reference to Figures 1 and 2. Figure 13A is an alternative embodiment of a solar cell 22f shown in Figure 1, having a convex receiving surface 70a. The convex receiving surface 70a is convenient, because it can more efficiently receive the radiation impacting the solar cell 22f from different directions, than would the flat solar cell 22 shown in Figure 1. When the radiation of impact is not focused in a precise way directly on the center of the solar cell, the curved shape of the receiving surface 70a can provide a greater amount of surface area, including the area that is normal to the impact radiation, reducing this Thus, the possibility of radiation coming out of the receiving surface (for example, being received at an angle approximately equal to, or greater than, the critical angle of the receiving surface). In a similar manner, the alternating solar cells 22g and 22h shown in Figures 13b and 13c have receiving surfaces 70b and 70c, respectively, configured to receive radiation that may not be directly focused on the center of the respective solar cell. By For example, the receiving surface 70c on the side of the solar cell 22h can be configured to receive the radiation directed towards the solar cell from the left, which crosses the radiation directed towards the solar cell from the right, before impacting the receiving surface. In yet another alternative embodiment of the solar cell shown in Figure 13D, a plurality of spherical solar cells 22i are embedded in a strip 80. Each solar cell 22i has a spherical radiation receiving surface 70d configured to receive the impact radiation. The space between the solar cells 22i can be filled with an optical adhesive (not shown) of a composition similar to that of the adhesive layer 36 discussed above with reference to Figures 1 and 2. The strip 80, with the solar cell 22i and the bonded adhesive 82 may replace the solar cell 22 shown in Figures 1 and 2. Although specific embodiments and examples of the present invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, such as It will be recognized by experts in the relevant field. The teachings provided herein, of the present invention, can be applied to other solar cell assemblies, and not necessarily to the example assemblies described above. Solar cells having different characteristics from those described herein, and reflective members comprising different materials, and having refractive indices different from those described herein, may be employed under the present invention, without deviating from the scope of the present invention. invention. In addition, the reflective member described herein may be used to reflect and / or focus radiation for purposes other than energy conversion by solar cells. All of the patents and applications of the previous United States of America are hereby incorporated by reference, as if they were stipulated in their entirety. The foregoing and other changes to the invention can be made in light of the above detailed description. In general, in the following claims, the terms used should not be construed to limit the invention to the specific embodiments disclosed in the specification and claims, but should be construed to include all assemblies of solar cells operating under the claims, to provide focused radiation to solar cells. In accordance with the foregoing, the invention is not limited by the disclosure, but instead its scope must be determined entirely by the following claims.

Claims (45)

1. An assembly of solar cells, which comprises: a reflective member having first and second opposing surfaces, the first surface being substantially transparent, the second surface having a transparent portion and a plurality of opaque reflecting portions, the reflecting portions being positioned to receive the radiation passing through the first surface of the reflecting member, and focusing and reflecting the radiation to form focused radiation directed towards the first surface, at an angle relative to the first surface greater than a critical angle of the first surface, the first surface to direct the focused radiation away from the first surface, the focused radiation converging as it moves away from the first surface; a solar cell having a radiation receiving surface fixed to the transparent portion of the second surface of the reflecting member, and positioned to receive the focused radiation.

The assembly of claim 1, wherein the reflective member comprises: a support layer having first and second opposing surfaces, the first surface of the reflecting member comprising the second surface of the support layer; and a film layer having first and second opposing surfaces, the first surface of the film layer being bonded to the first surface of the support layer, the second surface of the reflecting member comprising the second surface of the film layer, wherein wherein each opaque reflective portion of the reflective member includes a reflective metallic layer positioned to direct a portion of the radiation focused through the film layer and the support layer, to the second surface of the support layer, without impacting another reflective portion .

The assembly of claim 1, wherein the reflective member comprises: a support layer having first and second opposing surfaces, the first surface of the reflecting member comprising the second surface of the support layer; and a film layer having first and second opposing surfaces, the first surface of the film layer being bonded to the first surface of the support layer, and forming the second surface of the reflecting member.

The assembly of claim 1, wherein each reflecting portion of the reflective member is positioned to direct the focused radiation toward the first surface without impacting another reflecting portion.

The assembly of claim 1, wherein the solar cell has first and second ends separated, and is elongated along a longitudinal axis extending between the ends, and the reflecting portions are elongated substantially parallel to the longitudinal axis.

The assembly of claim 1, wherein the solar cell has a substantially circular shape, and the reflective portions extend concentrically around the solar cell.

The assembly of claim 1, wherein the radiation receiving surface of the solar cell has first and second edges separated, and a central region intermediate the edges, impacting the focused radiation on the central portion of the radiation receiving surface. .

The assembly of claim 1, wherein the solar cell is a first solar cell, the plurality of opaque reflecting portions is a first plurality, the radiation comprises a first portion of radiation, and the focused radiation is a first portion of radiation focused, further comprising: a second plurality of opaque reflecting portions positioned to receive a second portion of radiation passing through the first surface of the reflecting member, and focusing and reflecting the second portion of radiation to form a second portion of focused radiation directed towards the first surface, at an angle in relation to the first surface, greater than a critical angle of the first surface, the first surface being placed to direct the second portion of focused radiation away from the first surface, the radiation of the second surface converging portion of radiation focused as it moves away from the first surface; and a second solar cell having a radiation receiving surface linked to a second transparent portion of the second surface of the reflecting member, and positioned to receive the second portion of focused radiation.

The assembly of claim 1, wherein the reflective member comprises acrylic, and the solar cell is a first solar cell, the plurality of opaque reflecting portions is a first plurality, the radiation comprises a first portion of radiation, and the radiation focused is a first portion of focused radiation, further comprising: a second plurality of opaque reflective portions positioned to receive a second portion of radiation passing through the first surface of the reflective member, and focusing and reflecting the second portion of radiation for forming a second portion of focused radiation directed toward the first surface at an angle relative to the first surface greater than a critical angle of the first surface, the first surface being positioned to direct the second portion of focused radiation away from the first surface, converging the radiation of the second portion of radiation and Focused as it moves away from the first surface; and a second solar cell having a radiation receiving surface bonded to a second transparent portion of the second surface of the reflecting member, and positioned to receive the second portion of focused radiation, the second solar cell of the first solar cell being separated by a distance in the range of approximately 1.8 to 2.22 times the thickness of the reflecting member.

The assembly of claim 1, wherein the solar cell is a first solar cell, the plurality of opaque reflecting portions is a first plurality, the radiation comprises a first portion of radiation, and the focused radiation is a first portion of radiation focused, further comprising: a second plurality of opaque reflecting portions positioned to receive a second portion of radiation passing through the first surface of the reflective member, and focusing and reflecting the second portion of radiation to form a second portion of focused radiation directed towards the first surface at an angle in relation to the first surface greater than a critical angle of the first surface, the first surface being positioned to direct the second portion of focused radiation away from the first surface, the radiation of the second focused portion converging as it moves away from the first its surface; and a second solar cell having a radiation receiving surface bonded to a second transparent portion of the second surface of the reflecting member, and positioned to receive the second portion of focused radiation, the second solar cell being separated from the first solar cell by a distance approximately equal to 1.0 to 2.22 times the thickness of the reflecting member.

The assembly of claim 1, wherein the solar cell is a first solar cell, the plurality of opaque reflecting portions is a first plurality, the radiation comprises a first portion of radiation, and the focused radiation is a first portion of radiation focused, further comprising: a second plurality of opaque reflecting portions positioned to receive a second portion of radiation passing through the first surface of the reflective member, and focusing and reflecting the second portion of radiation to form a second portion of radiation focused towards the first surface at an angle relative to the first surface greater than a critical angle of the first surface, the first surface being positioned to direct the second portion of focused radiation away from the first surface, the radiation of the second surface converging focused portion as it moves away from the first to surface; and a second solar cell having a radiation receiving surface linked to a second transparent portion of the second surface of the reflective member, and positioned to receive the second focused radiation portion, each of the first plurality of reflective portions comprising a reflecting metallic layer for directing the first portion of the radiation focused through the reflecting member towards the first surface, metal layers being electrically adjacent to one another to form a continuous conductive layer extending between the first and second solar cells, coupling the first and second solar cells electrically with the conductive layer.

The assembly of claim 1, wherein the reflective member comprises an acrylic material.

The assembly of claim 1, wherein the reflective member comprises glass.

14. The assembly of claim 1, wherein the radiation receiving surface of the solar cell is substantially planar.

The assembly of claim 1, wherein the solar cell radiation receiving surface is convex, having first and second edges separated, and a central region intermediate the edges, with the first surface of the reflective member being located closest to the central region of the solar cell that from its banks.

The assembly of claim 1, wherein the radiation receiving surface of the solar cell is concave, having first and second edges separated, and a central region intermediate the edges, with the first surface of the reflecting member being located further away from the central region of the solar cell that from its banks.

The assembly of claim 1, wherein the solar cell is a first solar cell, and the radiation comprises a first portion of radiation, which further comprises second, third, and fourth solar cells, and wherein the plurality of reflective portions opaque includes a first reflective portion positioned to reflect to the first portion of radiation toward the first solar cell, a second reflective portion opposite the first reflective portion, and positioned to reflect a second portion of radiation toward the second solar cell, a third portion reflective placed intermediate .- ** * & & amp; * to the first and second reflecting portions, to reflect a third portion of radiation towards the third solar cell, and a fourth reflecting portion opposite the third reflecting portion, to reflect a fourth portion of radiation towards the fourth solar cell.

The assembly of claim 17, wherein the first, second, third, and fourth reflective portions each have a triangular shape, the reflecting portions joining at a common point to form a pyramidal reflective element.

19. The assembly of claim 17, wherein at least one of the reflecting portions has a flat surface.

The assembly of claim 17, wherein at least one of the reflecting portions has a curved surface.

The assembly of claim 17, wherein the reflecting portions together comprise a first reflective element, and the solar cells together comprise a first group of solar cells, the first group of solar cells having a first diagonal axis extending from the reflective element between the first and third solar cells, and a second diagonal axis extending from the reflective element between the second and third solar cells, which further comprises a second reflective element and a second , * «.. > i? .. ii: ß r-i 'aS group of solar cells adjacent to the first reflecting element and to the first group of solar cells, respectively, the second reflective element being placed on one of the first and second diagonal axes.

22. An assembly of solar cells which comprises: a reflective member having first and second opposing surfaces, the first surface being at least partially transparent, the second surface having a plurality of reflective portions, the reflecting portions being positioned to receive the radiation that passes through the first surface of the reflective member, and converge and reflect the radiation to form convergent radiation directed towards the first surface at an angle relative to the first surface greater than a critical angle of the first surface, the first surface being placed to direct the convergent radiation away from the first surface, the converging radiation converging as it moves away from the first surface; and a solar cell positioned at least close to the reflecting member, the solar cell having a radiation receiving surface positioned to receive the directed convergent radiation away from the first surface, and generate an electric current therefrom.

The assembly of claim 22, wherein the reflective member comprises: a support layer having first and second opposing surfaces, the first surface of the reflective member comprising the second surface of the support layer; and a film layer having first and second opposed surfaces, the first surface of the film layer being bonded to the first surface of the support layer, the second surface of the reflecting member comprising the second surface of the film layer, wherein each reflective portion of the reflecting member includes a reflective metallic layer positioned to direct a portion of the converging radiation through the film layer and the support layer, towards the second surface of the support layer, without impacting another reflective portion .

The assembly of claim 22, wherein each reflective portion of the reflective member is positioned to direct the convergent radiation toward the first surface, without impacting another reflective portion.

The assembly of claim 22, wherein the solar cell is a first solar cell, the plurality of reflective portions is a first plurality, the radiation comprises a first portion of radiation, and the converging radiation is a first portion of convergent radiation , which also comprises. a second plurality of reflective portions positioned to receive a second portion of radiation passing through the first surface of the reflecting member, and converging and reflecting the second portion of radiation to form a second portion of convergent radiation directed toward the first surface in an angle in relation to the first surface greater than a critical angle of the first surface, the first surface being positioned to direct the second portion of convergent radiation away from the first surface by the total internal reflection, the radiation of the second portion of radiation converging convergent as it moves away from the first surface; and a second solar cell positioned at least close to the reflecting member, the second solar cell having a radiation receiving surface positioned to receive the second portion of convergent radiation, and generating an electric current therefrom.

The assembly of claim 22, wherein the solar cell is a first solar cell, the plurality of reflective portions is a first plurality, the radiation comprises a first portion of radiation, and the converging radiation is a first portion of convergent radiation , which further comprises: a second plurality of reflective portions positioned to receive a second portion of radiation that S?,?? K * í & '# #? Fe' s passes through the first surface of the reflecting member, and converge and reflect the second portion of radiation, to form a second portion of convergent radiation directed towards the first surface at an angle relative to the first surface greater than a critical angle of the first surface, the first surface being positioned to direct the second portion of converging radiation away from the first surface, the radiation of the second converging radiation portion converging as it moves away from the first surface; and a second solar cell having a radiation receiving surface bonded to a second transparent portion of the second surface of the reflecting member, and positioned to receive the second convergent radiation portion, each of the first plurality of reflective portions comprising a metal layer reflective placed to direct the first portion of the convergent radiation through the reflecting member towards the first surface, electrically coupling metal layers adjacent to each other to form a continuous conductive layer extending between the first and second solar cells, electrically coupling the first and second solar cells to the conductive layer.

27. The assembly of claim 1, wherein the solar cell is a first solar cell, and the radiation ÍSSÉ & . - 5 * 51 comprises a first "portion of radiation," further comprising second and third solar cells, and wherein the plurality of reflected portions includes a first reflective portion positioned to reflect the first portion of radiation toward the first solar cell , a second reflecting portion opposite the first reflective portion, and positioned to reflect a second portion of radiation towards the second solar cell, the first and second solar cells defining an axis extending therebetween, the reflecting portions further including a third reflecting portion positioned intermediate the first and second reflecting portions, to reflect a third portion of radiation towards the third solar cell, the third solar cell of the axis extending between the first and second solar cells being offset.

28. An assembly of solar cells, which comprises: a solar cell having a radiation receiving surface positioned to receive radiation and generate an electric current therefrom; a reflective layer having a first substantially transparent surface, and a second surface opposite the first, the second surface having a link portion linked to the solar cell's radiation receiving surface, and a plurality of separate reflecting portions, each reflective portion for ..jseaaaasr ^ r ^ s: receive a portion of radiation that passes through the reflecting layer from the first surface to the second surface, and re-direct in a reflective manner the portion of radiation along a reflected path which extends away from the second surface, the reflected trajectories approaching one another as they extend away from the second surface; and a substantially transparent support layer having a first surface bonded to the first surface of the reflecting layer, and a second surface opposite to the first, the support layer having a refractive index sufficient to receive the portions of radiation reflected from the reflecting layer, and redirecting by the total internal reflection the portions of radiation along the redirected trajectories that extend away from the first surface towards the solar cell, approaching the paths redirected to each other as they extend away from the solar cell. the first surface.

The assembly of claim 28, wherein the reflective member comprises: a support layer having first and second opposing surfaces, the first surface of the reflective member comprising the second surface of the support layer; and a film layer that has first and second * opposite surfaces, the first surface of the film layer being bonded to the first surface of the support layer, and forming the second surface of the reflective member.

The assembly of claim 28, wherein the reflective layer can be bent in a direction normal to its first surface, and the support layer is substantially rigid in a direction normal to the first surface thereof, and adhesively bonded to the reflective layer to restrict the bend of the reflective layer in the direction normal to the first surface of the reflecting layer, each reflecting portion of the reflecting layer comprising a reflective metallic layer positioned to reflect the radiation from the reflecting portion through the reflecting layer. reflecting layer and support layer, each reflective portion being positioned to redirect the radiation portion along the corresponding reflected trajectory without impacting another reflective portion.

The assembly of claim 28, which further comprises an adhesive layer positioned between the support layer and the reflective layer, for bonding the support layer and the reflective layer together, the adhesive layer having a substantially equal refractive index at a refractive index of the support layer.

The assembly of claim 28, which further comprises an adhesive layer placed between the support layer and the reflective layer, for bonding the support layer and the reflective layer together, the adhesive layer having a substantially equal refractive index at a refractive index of the reflecting layer.

The assembly of claim 28, wherein the reflective layer has a refractive index substantially equal to a refractive index of the support layer.

The assembly of claim 28, wherein the reflective layer comprises an acrylic material, and the support layer comprises glass.

35. An assembly of solar cells, which comprises: a solar cell having a radiation receiving surface positioned to receive radiation and generate an electric current therefrom; a reflective layer having a first substantially transparent surface, and a second surface opposite the first, the second surface having a link portion linked to the solar cell's radiation receiving surface, and a plurality of separate reflecting portions, each reflective portion to receive a portion of radiation that passes through the reflecting layer from the first surface to the second surface, and to re-direct in a reflective manner the portion of radiation along a reflected path extending away from the second surface, the reflected trajectories approaching each other as they extend away from the second surface, the first surface of the reflective layer having a refractive index sufficient to receive the reflected radiation portions from its second surface, and redirecting the radiation portions by the reflection i Total normal to the solar cell, converging the radiation portions as they move away from the first surface.

36. The assembly of claim 35, wherein the reflective portions each comprise a reflective metallic layer positioned to reflect radiation from the reflecting portions through the reflecting member toward the first surface, each reflecting portion being positioned to redirect the portion of radiation along the corresponding reflected path without impacting another reflective portion.

37. An assembly of solar cells, which comprises: first and second separated solar cells, each having a radiation receiving surface; and a reflective member having first and second opposing surfaces, the first surface being substantially transparent, the second first and second surface having transparent portions linked to the radiation receiving surfaces of the first and second solar cells, respectively, the second surface also having a plurality of opaque mirror units, each reflective portion having a first facet and a second adjacent facet, each of the first facets having a different angular orientation relative to the first surface, to collectively receive a first portion of radiation passing through the first surface of the reflecting member, and focusing in a reflective manner and redirecting the first portion of radiation towards the first surface at an angle relative to the first surface greater than a critical angle of the first surface, the first surface being placed to direct the first portion of radiation away from the first surface towards the first solar cell, the first portion of radiation converging as it moves away from the first surface, each of the second having facets a different angular orientation in relation to the first surface, to collectively receive a second portion of radiation passing through the first surface of the reflecting member, and to focus in a reflective manner and to redirect the second portion of radiation towards the first surface at an angle in relation to the first surface, greater than a critical angle of the first surface, the first surface being placed to direct the second portion of radiation away from the first surface towards the second solar cell, the second portion of radiation converging as it moves away of the first surface.

38. A reflective assembly for focusing radiation, which comprises: a reflective member having first and second opposing surfaces, the first surface being at least partially transparent, the second surface having a plurality of reflective portions, the reflective portions being positioned to receive the radiation passing through the first surface of the reflecting member, and focusing and reflecting the radiation to form focused radiation directed towards the first surface, at an angle relative to the first surface, greater than a critical angle of the first surface, being placed the first surface to direct the focused radiation away from the first surface, the focused radiation converging as it moves away from the first surface.

39. A method for focusing radiation on a radiation receptor surface of a solar cell, which comprises: directing the radiation through a first -eßm Szz. substantially transparent surface of a reflecting member towards a second surface of the reflective member opposite the first surface; reflecting a first portion of the radiation away from a first opaque portion of the second surface, to form a first portion of reflected radiation directed toward the first surface; reflecting a second portion of the radiation away from a second opaque portion of the second surface, to form a second portion of reflected radiation directed toward the first surface, and toward the first portion of reflected radiation; re-reflecting the first and second portions of reflected radiation towards the first surface, to direct the portions of reflected radiation towards each other, and toward the receiving surface of the solar cell.

40. The method of claim 39, wherein the act of reflecting the first portion of the radiation includes directing the first portion of reflected radiation toward the first surface at an angle greater than a critical angle of the first surface.

41. The method of claim 39, wherein the act of reflecting the second portion of the radiation includes directing the second portion of reflected radiation toward the first surface at an angle greater than a critical angle of the reflective member.

42. The method of claim 39, which further comprises selecting a thickness of the reflective member to direct the first and second portions of reflected radiation to substantially impact the same location on the radiation receiving surface of the solar cell.

43. The method of claim 39, further comprising selecting a thickness of the reflective member to direct the first and second portions of the reflected radiation to impact the solar cell's radiation receiving surface in first and second separate locations , respectively.

44. The method of claim 39, wherein it further comprises selecting a thickness of the reflective member to focus the first and second portions of reflected radiation by a desired amount on the receiving surface of the solar cell.

45. The method of claim 39, wherein the act of reflecting the second portion of the radiation includes preventing the second portion of reflected radiation from impacting the first opaque portion.