HK1168468A - Concentrator-type photovoltaic (cpv) modules, receivers and sub-receivers and methods of forming same - Google Patents

Description

Concentrator-type photovoltaic (CPV) modules, receivers and sub-receivers and methods of forming the same

Reference to priority application

The disclosures of U.S. provisional application No.61/151,073 filed on 9/2/2009, 61/151,083 filed on 9/2/2009, and 61/166,513 filed on 3/4/2009, the disclosures of which are hereby incorporated by reference, are claimed.

Technical Field

The present invention relates to integrated circuit devices and methods of forming the same, and more particularly, to optoelectronic devices and methods of forming the same.

Background

Concentrated Photovoltaic (CPV) systems concentrate sunlight onto a photovoltaic surface for the production of electricity. CPV systems are typically mounted on solar trackers to maintain the focus of the light on the photovoltaic surface as the sun moves through the sky. Early examples of CPV systems used acrylic fresnel lenses to focus light on water cooled silicon solar cells and used biaxial solar tracking. Other examples of CPV systems use hybrid silicone-glass fresnel lenses and use passive heat sinks for solar cell cooling.

The semiconductor properties allow solar cells to operate more efficiently in concentrated light systems, provided that the cell junction temperature is kept sufficiently cold with appropriate heat sinks. CPV systems operate most efficiently in direct sunlight because the scattered light resulting from cloudy conditions is generally not concentrated efficiently.

CPV systems offer advantages over conventional flat panel solar cells because CPV solar concentrators are generally less expensive than equivalent area solar cells. CPV system hardware (solar concentrators and trackers) are reasonably priced below $3/Watt, while silicon flat panels are typically sold at a price of $3- $ 5/Watt.

Low concentration CPV systems typically have solar concentration levels of 2-100 suns. For economic reasons, conventional or retrofit silicon solar cells are generally used, and at these concentrations the heat flux is low enough that the cells generally do not need to be actively cooled. The laws of optics suggest that solar concentrators with low concentrations can have high acceptance angles. Thus, low concentration CPV systems generally do not require active sun tracking. A medium concentration CPV system, typically having a solar concentration level of 100 to 300 suns, requires sun tracking and cooling. High Concentration Photovoltaic (HCPV) systems use concentrating optics consisting of dish reflectors or fresnel lenses that concentrate sunlight to an intensity of 300 sun or more. Solar cells in these HCPV systems typically require high capacity heat sinks to prevent thermal damage and manage temperature-related performance losses. Multijunction solar cells are currently favored over silicon solar cells because they are generally more efficient. Although the cost of a multijunction solar cell can be 100 times that of a comparable silicon cell, the cell cost is typically only a small factor of the cost of the overall CPV system, meaning that system economics are generally biased toward the use of multijunction cells.

Disclosure of Invention

Methods of forming concentrator-type photovoltaic (CPV) receivers according to some embodiments of the present invention include forming a solar cell and a self-centering lens support on a substrate. The self-centering lens support is preferably formed to have an opening therein that exposes the light receiving surface of the solar cell. A spherical lens is also formed on the self-centering lens support opposite the light receiving surface of the solar cell. According to some of these embodiments of the invention, the spherical lens is sealed to the opening in the self-centering lens support. Preferably, the seal is a hermetic seal. The sealing operation may include annealing the spherical lens and the self-centering lens support at a temperature in a range from about 150 ℃ to about 350 ℃. This annealing of the lens and the lens support may be performed in a chemically inert environment. Examples of chemically inert environments include nitrogen and/or argon environments that may be free of oxygen.

According to a further embodiment of the invention, the step of forming the self-centering lens support is preceded by the step of forming a pair of electrical interconnect structures on the light-receiving surface of the solar cell. The step of forming a self-centering lens support may then comprise depositing a self-centering lens support onto the pair of electrical interconnect structures. The self-centering lens support may be annular. According to a further embodiment of the present invention, the step of forming the spherical lens on the self-centering lens support may be preceded by forming an annular sealing structure on the substrate around the self-centering lens support. The annular sealing structure may have a diameter larger than the diameter of the self-centering lens support. The annular sealing structure is generally concentrically arranged with respect to the self-centering lens support. Based on these embodiments of the present invention, a concentrator-type photovoltaic (CPV) receiver can include a solar cell on a substrate and a self-centering annular lens support having an opening therein that exposes a light-receiving surface of the solar cell. The lens disposed on the self-centering lens support extends opposite the light receiving surface.

Concentrator-type photovoltaic (CPV) modules according to further embodiments of the present invention may include a back sheet having a series of 1mm thereon²Or smaller solar cells. These cells may have a thickness of less than about 20 μm. And a bottom plate interconnection network is also arranged on the back plate. The backplane interconnect network operates to electrically connect the series of solar cells together. A front panel is also provided spaced from the back panel. The front plate includes a series of primary lenses thereon facing the series of solar cells. In particular, the front plate is configured to provide a lens-to-cell light concentration of greater than 1000 times to the series of solar cells. To achieve this 1000 x lens-to-cell light concentration, the primary lens can be configured as a plano-convex lens with a lens depression of less than about 4 mm. In particular, the lens can be configured to have a lens recess defined by the following relationship:

recess ═ f (n-1) - ((f (n-1))²-(1/2d)²)^1/2

Where f is the focal length of the lens, n is the refractive index of the lens, and d is the diameter of the lens.

According to further embodiments of the present invention, a series of secondary optical elements may be provided that extend between the series of primary lenses and the series of solar cells. Each of the secondary optical elements is mounted close to the light receiving surface of the corresponding solar cell. In particular, each of the secondary optical elements may be configured to have a center of mass substantially aligned with a center of the light receiving surface of the corresponding solar cell. The secondary optical elements may be spherical lenses having a diameter of less than about 5 mm. According to further embodiments of the present invention, the size, shape, configuration, and location of the secondary optical elements relative to the series of solar cells in combination are sufficient to increase the acceptance angle of the CPV module relative to an otherwise equivalent module without the series of secondary optical elements.

Further embodiments of the present invention include Concentrator Photovoltaic (CPV) modules. These modules include a front plate having a series of primary lenses thereon and a back plate having a series of solar cells thereon facing the series of primary lenses. A series of secondary optical elements are also provided, extending between the series of primary lenses and the series of solar cells. A bottom plate is also arranged. The backplane, which electrically connects the series of solar cells together, extends between the backplane and the series of solar cells. According to some embodiments of the invention, the backplane comprises a first interconnection network and a second interconnection network electrically connected to the first terminal and the second terminal of the series of solar cells, respectively. A plurality of overvoltage protection diodes are also provided. The diodes have a cathode terminal electrically connected to the first interconnection network and an anode terminal electrically connected to the second interconnection network.

The front plate has a first light receiving surface thereon. Each of the plurality of primary lenses is configured to concentrate light received at the first surface of the front plate onto a respective optical element of the series of secondary optical elements. In addition, each of the plurality of secondary optical elements may be further configured to concentrate light received from the series of primary lenses onto a light receiving surface of a respective solar cell of the series of solar cells. The frame may also be mounted to the back plate. The frame is configured to support a front panel opposite the series of solar cells. According to a further embodiment of the invention, the front plate and the series of main lenses may be configured as an abutment (contiguous piece) or a compound of an optically transparent material. For example, the series of primary lenses may be laminated or molded onto the inner surface of the front plate. The primary lens may be a plano-convex lens.

According to still further embodiments of the present invention, a backplane interconnect network includes at least one metal layer. For example, the backplane interconnect network may include a copper layer having a thickness in a range from about 10 μm to about 50 μm. In addition, the backplane interconnect network may include a first local release metal layer on a major surface of the backplane. The first local release metal layer may be configured to act as a heat sink for the series of solar cells. A second partial release metal layer may also be provided on the minor surface of the backplane extending opposite the major surface of the backplane. The second partial release metal layer may act as a heat sink for the backplane. According to still further embodiments of the present invention, each of the plurality of secondary optical elements may have a convex surface facing a respective one of the plurality of primary lenses and a convex surface facing a lower solar cell of the series of solar cells.

Methods of forming concentrator-type photovoltaic (CPV) modules according to still further embodiments of the present invention include forming a front sheet having a series of primary lenses thereon and a back sheet having a series of solar cells thereon facing the series of primary lenses. A series of secondary optical elements are also formed that are formed to extend between the series of primary lenses and the series of solar cells. A backplane interconnect network is formed extending between the backplane and the series of solar cells, electrically connecting the series of solar cells together.

According to some of these embodiments of the invention, the step of forming the backplane interconnect network comprises depositing a metal layer on the major surface of the backplane and then patterning the metal layer into a first backplane and a second backplane, the first backplane being electrically connected to the first terminal of the solar cell and the second backplane being electrically connected to the second terminal of the solar cell. In some of these embodiments of the invention, the step of depositing the metal layer on the major surface may be preceded by forming an electrically insulating release layer on the major surface. The step of patterning the metal layer may also be followed by the step of selectively removing portions of the electrically insulating release layer extending between the first backplane and the major surface of the backplane.

Optoelectronic devices according to further embodiments of the present invention include a first substrate of a first material having at least a first conductive via therein extending between first and second opposing surfaces of the first substrate. A second substrate of a second material different from the first material is provided on the first substrate. The second substrate includes a solar cell having a light receiving surface thereon, and first and second terminals electrically connected with the first and second regions in the solar cell. A first conductive film is provided on the light receiving surface. The first conductive film extends from the first terminal of the solar cell to the first conductive via and onto the first surface of the first substrate. The solar cell may be a compound semiconductor solar cell, and the first region and the second region in the solar cell may be semiconductor regions having opposite conductivity types. A second conductive via may also extend between the first and second opposing surfaces of the first substrate, and a second conductive film may be provided that extends from the second terminal of the solar cell to the second conductive via.

An optoelectronic device in accordance with another embodiment of the present invention includes a first substrate of a first material having at least a first conductive structure thereon extending between first and second opposing surfaces of the first substrate. A second substrate of a second material different from the first material is provided on the first substrate. The second substrate includes a solar cell having a light receiving surface thereon, and first and second terminals electrically connected with the first and second regions in the solar cell. A first conductive film is provided on the light receiving surface. The first conductive film extends from a first terminal of the solar cell to the first conductive structure.

Drawings

Fig. 1a-1c are cross-sectional views illustrating a Concentrated Photovoltaic (CPV) sub-receiver and receiver according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of a CPV sub-receiver according to an embodiment of the present invention.

Fig. 3a-3c are cross-sectional views of CPV sub-receivers according to embodiments of the present invention.

FIG. 4 is a cross-sectional view of a CPV sub-receiver having a secondary lens element thereon according to an embodiment of the present invention.

Fig. 5a is a cross-sectional view of a CPV sub-receiver of an underlying mounted backplane interconnect network in accordance with an embodiment of the present invention.

FIG. 5b is a cross-sectional view of a CPV receiver with a secondary ball lens according to an embodiment of the present invention.

Fig. 6 is a cross-sectional view of a portion of a CPV module according to an embodiment of the present invention.

FIG. 7 is a plan view of a two-dimensional array of CPV sub-receivers mounted on an underlying backplane interconnect network in accordance with an embodiment of the present invention.

Fig. 8 is a generalized cross-sectional view of a CPV module having a primary lens element and a secondary lens element therein according to an embodiment of the present invention.

Figures 9a-9b illustrate a method of forming a backplane interconnect network having self-releasing heat spreading elements according to an embodiment of the present invention.

Fig. 10a-10c are cross-sectional views illustrating a CPV receiver according to an embodiment of the present invention.

11a-11c are flow diagrams illustrating a CPV backplane assembly process according to an embodiment of the present invention.

Detailed Description

The present invention will now be described more fully with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

It will be understood that when an element or layer is referred to as being "on," "connected to" or "coupled to" another element or layer (and variations thereof), it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element or layer (and variations thereof), there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as "/".

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatially relative terms, such as "under", "below", "lower", "upper", "above", and the like, may be used herein to facilitate describing one element or feature's relationship to another element(s) or feature as illustrated. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," "including," "has," "having," and variations thereof, when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. Rather, the term "consisting of … …" when used in this specification is taken to specify the stated features, steps, operations, elements, and/or components, and excludes other features, steps, operations, elements, and/or components.

Embodiments of the present invention are described herein with reference to cross-sectional and perspective views, which are schematic illustrations of idealized embodiments (and intermediate structures) of the present invention. Thus, differences from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, sharp corners may be somewhat rounded due to manufacturing techniques/tolerances.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1a-1b show an optoelectronic device 10 according to an embodiment of the present invention. The optoelectronic device 10 includes a first substrate 12 of a first material, the first substrate 12 having a first conductive via 14a extending therein. The first conductive via 14a extends between the first and second opposing surfaces 12a, 12b of the first substrate 12. The first and second opposing surfaces 12a, 12b may be top and bottom surfaces, respectively. A second substrate 20 of a second material different from the first material is formed on the first substrate 12. The first substrate 12 and the second substrate 20 preferably comprise materials having substantially matched coefficients of thermal expansion (TCE). Typical materials that may be used for the first substrate 12 include, but are not limited to, aluminum oxide, aluminum nitride, silicon, and beryllium oxide.

The second substrate 20 comprises a solar cell having a light receiving surface 20a thereon, and first and second conductive terminals 22a, 22 b. These first and second terminals 22a, 22b are electrically connected to the first and second regions 23a, 23b in the solar cell, respectively. The first conductive film 24a is provided on the light receiving surface 20 a. The first conductive film 24a extends onto the first surface 12a of the first substrate 12 and electrically connects the first terminal 22a of the solar cell to the first conductive via 14 a. This electrical contact to the first terminal 22a may be provided within an opening in the patterned electrically insulating layer 25a, which electrically insulating layer 25a may further serve as an anti-reflective coating. The solar cell may be a multijunction solar cell having a compound semiconductor layer therein, and the first and second regions 23a, 23b may be semiconductor regions having opposite conductivity types (e.g., N-type, P-type). A second conductive via 14b may also extend between the first and second opposing surfaces 12a, 12b of the first substrate 12, and a second conductive film 24b may be provided extending from the second terminal 22b of the solar cell to the second conductive via 14 b. Electrical contact between the second terminal 22b and the second conductive film 24b may be disposed within an opening in the patterned electrically insulating layer 25 b. First and second output pads 26a, 26b are also provided adjacent the second surface 12b of the first substrate 12. As shown, the first and second output pads 26a, 26b are electrically connected to the first and second conductive vias 14a, 14b, respectively. These first and second output pads 26a, 26b provide a means for electrically connecting the terminals (e.g., anode and cathode terminals) of the solar cells within the second substrate 20 to an underlying receiver board (e.g., backplane).

These first and second output pads 26a, 26b enable the optoelectronic device 10 to function as a Concentrated Photovoltaic (CPV) sub-receiver that can be electrically connected to an underlying receiver substrate. This configuration of the CPV sub-receiver enables higher CPV receiver performance, higher precision, increased reliability, enhanced scalability, and reduced cost, among other things. In addition, the photovoltaic apparatus 10 of FIGS. 1a-1b allows the use of high precision, high throughput manufacturing processes, including photolithography, screen printing, laser drilling, and self-aligned surface mounting, to manufacture receivers suitable for small solar cells (< 1mm), including CPV systems using thin solar cells. These cells may have a thickness of less than 20 μm, or possibly less than 12 μm, or even less than 8 μm. These embodiments also enable CPV systems that advantageously use transfer printed solar cells, such as solar cells that are physically released from a growth substrate and recovered and printed using an embosser. An example of a transfer printed solar cell is described in U.S. patent No.7,622,367 to Nuzzo et al entitled "method and apparatus for fabricating and assembling printable semiconductor elements," the disclosure of which is incorporated herein by reference.

As described more fully below, embodiments of the present invention provide a sub-receiver for CPV applications that can be manufactured and assembled into a module in a cost-effective manner and that can be easily scaled to high volume production; providing a sub-receiver for CPV suitable for small solar cells (< 1mm) and/or thin solar cells (< 20 μm); providing a sub-receiver for CPV that can be assembled with good positional accuracy; and providing a sub-receiver for CPV comprising means for the transfer of electrical energy from the solar cell without damaging the solar cell. Thus, embodiments of the invention described herein provide a sub-receiver for CPV that does not require bonding wires, tapes, cables, or leads. Rather, these embodiments provide sub-receivers for CPV that include means for transferring electrical energy through thin and thick films, conductive vias, and/or laterally positioned vertical interconnect structures. These embodiments of the present invention also provide sub-receivers for CPV that can be quickly tested in a parallel fashion before racking, sorting and final assembly.

Thus, as shown in fig. 1c, the optoelectronic device 10 of fig. 1a can be electrically and mechanically bonded to an underlying receiver substrate 38 having patterned first and second conductive patterns 36a, 36b (e.g., a thick film interconnect structure) thereon. As shown, an electrically insulating passivation layer 34 is disposed on the first and second electrically conductive patterns 36a, 36 b. The passivation layer 34 is patterned to define openings therein that expose the conductive patterns 36a, 36 b. The first and second electrically conductive solder pads 32a, 32b are disposed on the electrically conductive patterns 36a, 36b using conventional techniques such as electroplating. These solder pads 32a, 32b may be electrically and mechanically bonded to the first and second output pads 26a, 26b, respectively, to define a mounted sub-receptacle. The mounted sub-receiver may be one of any series of interconnected sub-receivers that function as relatively high current optoelectronic devices/modules, as described more fully below.

Fig. 2 shows an optoelectronic device 10a according to another embodiment of the present invention. This opto-electronic device 10, which may be used as a sub-receiver within a CPV system, is similar to the device 10 of fig. 1a-1 b. However, as shown in fig. 2, the device 10a employs first and second conductive structures 15a, 15b located on the outer sidewall surfaces of the first substrate 12. As shown, these conductive structures 15a, 15b extend in a wound manner between the first and second opposing surfaces 12a, 12b of the first substrate 12. These structures 15a, 15b replace the conductive vias 14a, 14b shown in fig. 1a-1 b.

Fig. 3a-3c illustrate optoelectronic devices 10b-10d according to further embodiments of the present invention. The optoelectronic device 10b of fig. 3a is similar to the device 10 of fig. 1a-1 b. However, the conductive vias 14a, 14b of fig. 1a are replaced by vias 14a ', 14 b' having sloped sidewalls. The sloped sidewalls of the conductive vias 14a ', 14 b' may create a highly reliable electrical interconnect structure that supports vertical current flow between the first and second conductive films 24a, 24b and the first and second output pads 26a, 26 b. The optoelectronic device 10c of fig. 3b is similar to the optoelectronic device 10b of fig. 3 a. However, the conductive vias 14a, 14b are omitted. Alternatively, through-substrate trenches 27a, 27b having sloped sidewalls are formed in the first substrate 12 and then lined with first and second conductive layers 24a ', 24 b' that extend directly between the respective first and second terminals 22a, 22b and first and second output pads 26a, 26 b. The optoelectronic device 10d of fig. 3c is similar to the optoelectronic device 10a of fig. 2. However, the conductive structures 15a, 15b of fig. 2 are replaced by first and second conductive layers 24a ", 24 b" extending directly on opposite sidewalls of the first substrate 12. In addition, first and second output pads 26a ', 26 b' are disposed directly on the second surface 12b of the first substrate 12 and on the outside edges of the first and second conductive layers 24a ", 24 b", as shown.

The optoelectronic devices of fig. 1a-1c, 2 and 3a-3c may be used with optical elements that focus light onto the exposed light-receiving surface 20a of the solar cell within the second substrate 20. For example, fig. 4 shows a light receiving sub-receiver 40 having a light gathering optical element 42 therein, the light gathering optical element 42 being supported by a lens support device 44 opposite the first substrate 12. The support device 44 may be an annular support that provides a hermetic seal with the optical element 42, as described more fully below with respect to fig. 10a-10 c.

Fig. 5a-5b show additional light receiving sub-receivers 50a, 50b that use a ball lens 52 (e.g., a glass lens) in place of the condensing optical element 42 of fig. 4. In the sub-receiver configuration 50a of fig. 5a, an annular lens support 54 is disposed between the conductive films 24a, 24b and the ball lens 52. The "self-centering" lens support 54 is positioned to align the center of the spherical ball lens 52 with the center of the underlying solar cell substrate 20. The solar cell substrate 20 is disposed within a photovoltaic device 10, the photovoltaic device 10 is electrically and mechanically bonded to an underlying receiver substrate 38, and the receiver substrate 38 may serve as a monolithic backplane as will be more fully described below. In contrast, the sub-receiver configuration 50b of fig. 5b uses an annular lens support 54 mounted directly on an underlying receiver substrate 38 ', the receiver substrate 38' having first and second conductive patterns 36a ', 36 b' (e.g., thick film metallization) thereon.

As will be described with respect to fig. 6-9, embodiments of the present invention can be used to fabricate large arrays of miniature solar cells that achieve significant reductions in energy loss and wiring costs and provide higher voltage outputs. Additionally, the combination of miniature solar cells with a monolithic backplane design, as described herein, enables surface mount devices for economical manufacture of CPV modules. Embodiments of the present invention also enable the design of CPV modules with high reliability and extended lifetime. In particular, embodiments of the present invention are well suited for the fabrication of CPV systems using ultra-thin solar cells (e.g., multijunction cells) having substrate thicknesses of less than 20 microns, and even less than 12 microns. Embodiments of the present invention also use transfer printing of solar cell substrates such as those disclosed in the Nuzzo et al' 367 patent described above. In particular, embodiments of the present invention can be used in concentrator-type photovoltaic (CPV) modules that can be manufactured with a reduced number of assembly steps using a massively parallel assembly and interconnection process. These embodiments are able to meet the objectives of providing CPV modules with increased reliability, functionality, efficiency and weight advantages over prior art CPV modules. Additionally, the use of a leadless CPV sub-receiver, such as the sub-receivers shown in FIGS. 1-5, can provide significant advantages over prior art sub-receivers. These advantages include: due to efficient dissipation of heat from concentrated sunlight illuminated sub-receiver surfacesImproved receiver performance from scratch; has a lower I²More efficient transfer of R lost power; and precise matching of solar cell output characteristics, which allows for efficient interconnects for large area array applications.

Fig. 6 shows a concentrator-type photovoltaic (CPV) module 65 according to another embodiment of the present invention. The module is shown to include a backplane having a backplane interconnect network located thereon that operates to electrically connect a series of solar cells together. According to some embodiments of the invention, the underlying receiver substrate 38' may serve as a component of the backplate. As shown in fig. 5a-5b and fig. 6, the light-receiving sub-receivers 50b are disposed at spaced apart locations on the receiver substrate 38'. These light receiving sub-receivers 50b may be electrically interconnected to provide 1mm²A two-dimensional array of solar cell substrates 20 (or smaller) having a thickness of less than about 20 μm.

The backplane interconnect networks 36a ', 36b ' are disposed on a receiver substrate 38 '. The front plate 60, which is supported by an outer frame 64, is disposed in spaced relation to the back plate. The front plate 60, having an outer surface 60a on an outer panel 62a, is shown to include a series of primary lenses 62b thereon, the primary lenses 62b being located within the CPV module 65 and facing the series of solar cell substrates 20. The outer panel 62a and the series of primary lenses 62b may be constructed as an abutment or a single piece of material (e.g., glass) or as a laminated composite of optically transparent materials. According to some embodiments of the invention, the front sheet 60 may be configured to provide a lens-to-cell light concentration of greater than 1000 times to the series of solar cell substrates 20. To achieve this 1000 x lens-to-cell light concentration, the primary lens 62b can be configured as a plano-convex lens with a lens depression of less than about 4 mm. In particular, the lens can be configured to have a lens recess defined by the following relationship:

recess ═ f (n-1) - ((f (n-1))²-(1/2d)²)^1/2

Where "f" is the focal length of the lens and "n" is the refraction of the lens materialThe ratio, and "d" is the diameter of the lens. By way of example, a series of main lenses 62b made of standard BK 7 optical glass (n 1.51) and having a lens focal length of 100mm can produce a lens depression of less than 2mm when the lenses have a diameter of less than about 28 mm. Therefore, to achieve a CPV module with a concentration of at least 1000 times, the solar cell substrate 20 should have less than 1mm²The light receiving area of (a).

Fig. 7 is a plan view of a back plate 70 according to an embodiment of the present invention. The back sheet 70 is shown to include a receiver substrate 38 having a two-dimensional array of CPV sub-receivers 50a located thereon. These sub-receivers 50a are electrically connected to the first and second large area electrical interconnect structures 36a, 36b that make up the backplane interconnect network. These electrical interconnect structures may be formed as copper layers having a thickness in a range from about 10 μm to about 50 μm. An overvoltage protection diode 72 is also provided. The anode and cathode terminals of diode 72 are connected to electrical interconnect structures 36a, 36b as shown. These diodes 72 operate to limit the maximum magnitude of any reverse voltage present at the solar cell substrate 20 that generates little (or no) current. To provide a CPV module of 1000 times concentration, the number of solar cell substrates 20 is typically in the range of 1000 to 4000 per square meter of module aperture (for solar cells having a width in the range of 0.5mm to 1 mm). Since the output voltage generated by the solar cell substrate 20 is generally independent of substrate size, higher module output voltages can be achieved when large arrays of substrates 20 are connected in series columns by appropriate patterning of the electrical interconnect structures 36a, 36 b. In addition, as described more fully below with respect to fig. 9a-9b, the large area electrical interconnect structures 36a, 36b may also operate to perform a heat sink function in addition to the low resistance electrical interconnect function.

Fig. 8 is a generalized cross-sectional view of a CPV module according to further embodiments of the present invention. The generalized view illustrates how the parallel paths of light received at the outer surface 60a of the front plate 60 are redirected into the light collection paths 75a-75c by the main lens 62b located inside the front plate 60. These light-collecting paths 75a-75c pass through respective secondary optical elements 52 ', which secondary optical elements 52' may be configured as spherical ball lenses (or refractive lenses). Each of these secondary optical elements 52' is mounted close to the light receiving surface of the corresponding solar cell within the sub-receiver 50 a. While not wishing to be bound by any theory, it is expected that the use of the two-step light concentrator provided by the primary and secondary lenses can produce a light transmission efficiency of greater than 80% when the primary and secondary lens elements are coated with an anti-reflective coating and have a light acceptance angle of greater than ± 1 degree.

These sub-receivers 50a may be electrically connected together on the underlying receiver substrate 38, as shown in FIG. 7. According to some embodiments of the present invention, each of the secondary optical elements 52' may be configured to have a center of mass substantially aligned with a center of the receiving surface of the corresponding solar cell substrate 20. These secondary optical elements 52' may be spherical lenses having a diameter of less than about 5 mm. In particular, the size, shape, composition, and location of the secondary optical elements 52 'relative to the underlying series of solar cell substrates 20 in combination are sufficient to increase the acceptance angle of the CPV module relative to an otherwise equivalent module without the series of secondary optical elements 52'.

Fig. 9a-9b are cross-sectional views of a receiver substrate 38 ' that advantageously enhance the heat dissipation capability of at least some of the first and second conductive patterns 36a ', 36b ' (e.g., thick and thin film metallization layers). As shown in fig. 9a, an electrically insulating release layer 39a may be formed between portions of the first and second electrically conductive patterns 36a ', 36b ' and the underlying substrate 38 '. Furthermore, an electrically insulating release layer 39b may be disposed on the bottom surface of the receiver substrate 38' along with the conductive pattern 37 (e.g., a thick film metallization layer), with the conductive pattern 37 covering portions of the release layer 39 b.

To improve the efficiency of heat transfer (by radiation and convection) to the environment within the CPV module, the first and second conductive patterns 36a ', 36b ' and portions of the pattern 37 can be partially released from the underlying substrate 38 '. For example, as shown in fig. 9b, the release layers 39a, 39b may be patterned and then removed (e.g., by etching) to selectively release portions of the metal patterns 36a ', 36b ', and 37 from the substrate 38 '. While not wishing to be bound by any theory, the metal patterns 36a ', 36 b', and 37 may be deposited to have internal stresses therein. These stresses can be suitably modified to provide controlled peeling of portions of the pattern (e.g., heat sink "fins") when the release layers 39a, 39b are removed. These parts of the pattern are highlighted in fig. 9b with reference numerals 36a ", 36 b" and 37'.

Fig. 10a-10c illustrate methods of forming concentrator-type photovoltaic (CPV) receivers according to further embodiments of the present invention. In particular, fig. 10a shows a photovoltaic device 10e having a solar cell substrate 20 positioned on an underlying receiver substrate 38'. First and second conductive patterns 36a ' and 36b ' are also disposed on the receiver substrate 38 ' and on the terminals (e.g., anode and cathode terminals) of the solar cell substrate, as previously described. First and second self-centering lens holders 54 and 55 are disposed on the first and second conductive patterns 36a and 36 b'. These first and second self-centering lens supports 54 and 55 may be patterned as annular support/seal structures concentrically arranged with respect to each other and having openings that expose the light-receiving surface of the solar cell substrate 20.

As shown in fig. 10b, a spherical lens 52 is formed on the self-centering lens supports 54, 55, thereby defining a sub-receiver 50 b'. In some of these embodiments of the invention, the spherical lens 52 may be sealed to an opening in the self-centering lens support 54, 55. Preferably, the seal provided is a hermetic seal. The sealing operation may include annealing the spherical lens 52 and the self-centering lens supports 54, 55 at a temperature in a range from about 150 ℃ to about 350 ℃. This annealing of the lens 52 and the lens supports 54, 55 may be performed in a chemically inert environment. Examples of chemically inert environments include nitrogen and/or argon environments that may be free of oxygen.

Fig. 10c shows a sub-receiver 50b with a spherical lens 52 mounted on a self-centering lens support 54. As indicated by the optical paths indicated by reference numerals L1 and L2, the high precision alignment of the lens 52 with the solar cell substrate 20 provided by the self-centering lens support 54 can be used to improve the light collection efficiency of the sub-receiver 50b by redirecting off-center light onto the light receiving surface of the solar cell substrate 20, as highlighted by reference numeral L2.

11a-11c are flow diagrams illustrating a CPV backplane assembly process according to further embodiments of the present invention. As shown in fig. 11a, the assembly process 110a may include depositing a solar cell onto a substrate (e.g., a silicon wafer substrate) using a transfer printing technique, see block 112 a. An example of a transfer printing technique is disclosed in the aforementioned' 367 patent to Nuzzo et al. Metal deposition and patterning steps may then be performed to define electrical interconnect structures that contact the terminals of the solar cells with corresponding regions on the substrate (e.g., through-substrate conductive vias), see block 114 a. The steps of defining a self-centering lens support and a seal pattern adjacent to the lens support on the solar cell may be performed, see blocks 116a, 118 a. As described previously with respect to fig. 5-6 and 10a-10c, the self-centering lens supports may be formed as annular supports, and the seal pattern may be formed by depositing and patterning rings of seal material concentrically arranged with respect to the respective lens supports.

As shown in block 120a, the substrate (e.g., wafer) is then divided (e.g., along scribe lines) into a plurality of optoelectronic devices, such as those shown in fig. 1 a. As described herein, these photovoltaic devices may be used as solar cell sub-receivers. These steps of singulating the substrate may be followed by the steps of attaching the lens elements to a self-centering lens support and then curing/cross-linking the sealing pattern (e.g., using a thermal process) to hermetically seal the lens elements to the lens support, see blocks 122a, 124 a. In particular, the lens elements (e.g., spherical lenses) and the seal pattern may be annealed in a chemically inert environment at a temperature in a range from about 150 ℃ to about 350 ℃. The chemically inert environment may be an oxygen-free environment comprising nitrogen and/or argon. The sub-receivers with lens elements (e.g., ball lenses) may then be tested for functionality, see block 126 a. The sub-receivers that have passed the functional test may then be placed on the CPV module backplane in a two-dimensional array pattern, see block 128 a. As shown in fig. 1c and 5a, a backplane solder reflow operation may be performed to electrically connect the solar cell interconnect structures (e.g., output pads 26a, 26b) to the backplane metallization layers (e.g., patterns 36a, 36b), see block 130 a.

Referring now to fig. 11b, an alternative assembly process 110b may include depositing a solar cell onto a substrate (e.g., a silicon wafer substrate) using a transfer printing technique, see block 112 b. An example of a transfer printing technique is disclosed in the aforementioned' 367 patent to Nuzzo et al. Metal deposition and patterning steps may then be performed to define electrical interconnect structures that contact the terminals of the solar cells with corresponding regions on the substrate (e.g., through-substrate conductive vias), see block 114 b. The steps of defining a self-centering lens support and a seal pattern adjacent to the lens support on the solar cell may be performed, see blocks 116b, 118 b. As described previously with respect to fig. 5-6 and 10a-10c, the self-centering lens supports may be formed as annular supports, and the seal pattern may be formed by depositing and patterning rings of seal material concentrically arranged with respect to the respective lens supports.

As shown in block 126b, the solar cells and electrical interconnect structures may be tested at the "wafer" level to identify pass and fail equipment. Next, as shown in block 120b, the substrate (e.g., wafer) is then divided (e.g., along scribe lines) into a plurality of sub-receiver devices. The "qualified" devices may then be placed on the CPV module backplane in a two-dimensional array pattern, see block 128 b. As shown in block 122b, the lens element is attached to a self-centering lens support. A heat treatment step may then be performed to (i) cure/crosslink the seal pattern to hermetically seal the lens element to the lens support; and (ii) reflowing the backplane solder, which electrically connects the solar cell interconnect structures (e.g., output pads 26a, 26b) to the backplane metallization layer (e.g., patterns 36a, 36b), see blocks 124b, 130 b.

Referring now to fig. 11c, an additional assembly process 110c may include depositing a solar cell onto a substrate (e.g., a silicon wafer substrate) using a transfer printing technique, see block 112 c. Metal deposition and patterning steps may then be performed to define electrical interconnect structures that contact the terminals of the solar cells with corresponding regions on the substrate (e.g., through-substrate conductive vias), see block 114 c. The step of defining a self-centering lens support on the solar cell may be performed, see block 116 c. As shown in block 126c, the solar cells and electrical interconnect structures may be tested at the "wafer" level to identify pass and fail equipment. Next, as shown in block 120c, the substrate (e.g., wafer) is then divided (e.g., along scribe lines) into a plurality of sub-receiver devices. The "qualified" devices may then be placed on the CPV module backplane in a two-dimensional array pattern, block 128 c. As shown in blocks 118c and 122c, a seal pattern is formed adjacent to the lens support, and then the lens element is attached to the self-centering lens support. Next, a heat treatment step may be performed in order to (i) cure/crosslink the sealing pattern to hermetically seal the lens element to the lens support; and (ii) reflowing the backplane solder, which electrically connects the solar cell interconnect structures (e.g., output pads 26a, 26b) to the backplane metallization layer (e.g., patterns 36a, 36b), see blocks 124c, 130 c.

In the drawings and specification, there have been disclosed typical preferred embodiments of the invention; and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Claims (109)

1. A method of forming a concentrator-type photoreceiver comprising:

forming a solar cell on a substrate;

forming a self-centering lens support on the substrate, the self-centering lens support having an opening therein that exposes a light-receiving surface of the solar cell; and

forming a spherical lens on the self-centering lens support opposite the light receiving surface of the solar cell.

2. The method of claim 1, wherein said forming a spherical lens comprises sealing said spherical lens to said opening in said self-centering lens support.

3. The method of claim 2, wherein said sealing said spherical lens comprises annealing said spherical lens and said self-centering lens support at a temperature in a range from about 150 ℃ to about 350 ℃.

4. The method of claim 3, wherein said sealing said spherical lens comprises annealing said spherical lens and said self-centering lens in a chemically inert environment.

5. The method of claim 3, wherein the chemically inert environment is oxygen-free.

6. The method of claim 5, wherein the chemically inert environment comprises nitrogen and/or argon.

7. The method of claim 1, wherein the forming a spherical lens comprises hermetically sealing the spherical lens to the opening in the self-centering lens support.

8. The method of claim 1, wherein said forming said self-centering lens support is preceded by forming a pair of electrical interconnect structures on said light-receiving surface of said solar cell; and wherein said forming said self-centering lens support comprises depositing said self-centering lens support onto said pair of electrical interconnect structures.

9. The method of claim 1, wherein the self-centering lens support is annular; and wherein forming a spherical lens on the self-centering lens support is preceded by forming an annular sealing structure on the substrate surrounding the self-centering lens support.

10. The method of claim 9, wherein the annular sealing structure has a diameter greater than a diameter of the self-centering lens support; and wherein the annular sealing structure is concentrically arranged with respect to the self-centering lens support.

11. A method of forming a concentrator-type photoreceiver comprising:

forming a solar cell on a substrate;

forming a self-centering lens support on the substrate, the self-centering lens support having an opening therein that exposes a light-receiving surface of the solar cell; and

forming a lens on the self-centering lens support opposite the light receiving surface of the solar cell.

12. The method of claim 9, wherein the self-centering lens support is annular; and wherein forming a lens on the self-centering lens support is preceded by forming an annular sealing structure on the substrate surrounding the self-centering lens support.

13. The method of claim 11, wherein the forming a lens comprises hermetically sealing the lens to the opening in the self-centering lens support.

14. The method of claim 11, wherein said forming a lens comprises sealing said lens to said opening in said self-centering lens support; and wherein said sealing said lens comprises annealing said lens and said self-centering lens support at a temperature in the range of from about 150 ℃ to about 350 ℃.

15. The method of claim 14, wherein the sealing the lens comprises annealing the lens and the self-centering lens support in an oxygen-free environment.

16. A method of forming a concentrator-type photoreceiver comprising:

forming a solar cell on a substrate;

forming an annular lens support on the substrate, the annular lens support having an opening therein that exposes a light receiving surface of the solar cell; and

forming a lens on the annular lens support opposite the light receiving surface of the solar cell.

17. The method of claim 16, wherein said forming said annular lens support is preceded by forming a pair of electrical interconnect structures on said light-receiving surface of said solar cell; and wherein said forming the annular lens support comprises depositing the annular lens support onto the pair of electrical interconnect structures.

18. The method of claim 17, wherein the forming a lens comprises hermetically sealing the lens to the opening in the annular lens support.

19. A concentrator-type photoreceiver comprising:

a solar cell on the substrate;

a self-centering lens support on the substrate, the self-centering lens support having an opening therein exposing a light-receiving surface of the solar cell; and

a spherical lens on the self-centering lens support, the spherical lens opposing the light receiving surface of the solar cell.

20. A concentrator-type photoreceiver comprising:

a solar cell on the substrate;

a self-centering lens support on the substrate, the self-centering lens support having an opening therein exposing a light-receiving surface of the solar cell; and

a lens on the self-centering lens support, the lens being opposite the light receiving surface of the solar cell.

21. A concentrator-type photoreceiver comprising:

a solar cell on the substrate;

an annular lens support on the substrate, the annular lens support having an opening therein exposing a light receiving surface of the solar cell; and

a lens on the annular lens support, the lens opposing the light receiving surface of the solar cell.

22. A concentrator-type photovoltaic module comprising:

thereon with a series of 1mm²Or a back sheet of a smaller solar cell;

a backplane interconnect network on the backplane, the backplane interconnect network electrically connecting the series of solar cells together; and

a front plate spaced from the back plate, the front plate having a series of primary lenses thereon facing the series of solar cells and providing a lens-to-cell light concentration of greater than 1000 times to the series of solar cells.

23. The concentrator-type photovoltaic module of claim 22, wherein the main lens is a plano-convex lens having a lens depression of less than about 4 mm.

24. The concentrator-type photovoltaic module of claim 23, wherein the lens depression of the plano-convex lens is defined by the relationship:

recess ═ f (n-1) - ((f (n-1))²-(1/2d)²)^1/2

Where f is the focal length of the lens, n is the refractive index of the lens, and d is the diameter of the lens.

25. The concentrator-type photovoltaic module of claim 22, wherein the solar cell has a thickness of less than about 20 μ ι η.

26. The concentrator-type photovoltaic module of claim 22, further comprising a series of secondary optical elements extending between the series of primary lenses and the series of solar cells.

27. The concentrator-type photovoltaic module of claim 26, wherein each of the secondary optical elements is mounted proximate to the light-receiving surface of the respective solar cell.

28. The concentrator-type photovoltaic module of claim 27, wherein each of the secondary optical elements has a center of mass that is substantially aligned with a center of the light-receiving surface of the respective solar cell.

29. The concentrator-type photovoltaic module of claim 28, wherein the secondary optical element is a spherical lens having a diameter of less than about 5 mm.

30. The concentrator photovoltaic module of claim 29, wherein the size, shape, composition and location of the secondary optical elements relative to the series of solar cells combine to sufficiently increase the acceptance angle of the concentrator photovoltaic module relative to an otherwise equivalent module without a series of secondary optical elements.

31. The concentrator photovoltaic module of claim 27, wherein the size, shape, composition and location of the secondary optical elements relative to the series of solar cells combine to sufficiently increase the acceptance angle of the concentrator photovoltaic module relative to an otherwise equivalent module without a series of secondary optical elements.

32. A concentrator-type photovoltaic module comprising:

a front plate having a series of primary lenses thereon;

a back sheet having a series of solar cells thereon facing the series of primary lenses;

a series of secondary optical elements extending between the series of primary lenses and the series of solar cells; and

a backplane electrically connecting the series of solar cells together, the backplane extending between the backplane and the series of solar cells.

33. The concentrator-type photovoltaic module of claim 32, wherein the backplane comprises first and second interconnection networks electrically connected to the first and second terminals of the series of solar cells, respectively.

34. The concentrator photovoltaic module of claim 32, further comprising a plurality of overvoltage protection diodes, said diodes having a cathode terminal electrically connected to said first interconnection network and an anode terminal electrically connected to said second interconnection network.

35. The concentrator-type photovoltaic module of claim 32, wherein the front plate has a first light-receiving surface thereon, and wherein each of the plurality of primary lenses is configured to concentrate light received at the first surface of the front plate onto a respective optical element of the series of secondary optical elements.

36. The concentrator-type photovoltaic module of claim 35, wherein each of the plurality of secondary optical elements is further configured to concentrate light received from the series of primary lenses onto the light-receiving surface of a respective solar cell in the series of solar cells.

37. The concentrator photovoltaic module of claim 32, further comprising a frame mounted to the back sheet, the frame configured to support the front sheet opposite the series of solar cells.

38. The concentrator photovoltaic module of claim 32, wherein the front plate and the series of primary lenses are configured as an abutment of optically transparent material.

39. The concentrator photovoltaic module of claim 32, wherein the front plate and the series of primary lenses are constructed as a composite of optically transparent materials.

40. The concentrator photovoltaic module of claim 39, wherein the series of primary lenses are laminated or molded onto the interior surface of the front plate.

41. The concentrator photovoltaic module of claim 35, wherein the front plate and the series of primary lenses are configured as a composite of optically transparent material; and wherein the series of primary lenses are laminated or molded onto the inner surface of the front plate.

42. The concentrator-type photovoltaic module of claim 32, wherein the main lens is a plano-convex lens.

43. The concentrator-type photovoltaic module of claim 32, wherein the backplane interconnect network comprises at least one metal layer.

44. The concentrator photovoltaic module of claim 32, wherein the backplane interconnect network comprises a copper layer having a thickness in the range from about 10 μ ι η to about 50 μ ι η.

45. The concentrator-type photovoltaic module of claim 32, wherein the backplane interconnect network comprises a first local release metal layer on a major surface of the backplane.

46. The concentrator-type photovoltaic module of claim 45, wherein the first local release metal layer is configured to act as a heat sink for the series of solar cells.

47. The concentrator photovoltaic module of claim 46, further comprising a second local release metal layer on a secondary surface of the backplane extending opposite the major surface of the backplane, the second local release metal layer acting as a heat sink for the backplane.

48. The concentrator-type photovoltaic module of claim 36, wherein each of the plurality of secondary optical elements has a convex surface facing a respective one of the plurality of primary lenses and a convex surface facing a lower solar cell of the series of solar cells.

49. A method of forming a concentrator photovoltaic module, comprising:

forming a front plate having a series of primary lenses thereon;

forming a back sheet having a series of solar cells thereon facing the series of primary lenses;

forming a series of secondary optical elements extending between the series of primary lenses and the series of solar cells; and

forming a backplane interconnect network extending between the backplane and the series of solar cells, the backplane interconnect network electrically connecting the series of solar cells together.

50. The method of claim 49, wherein the forming a backplane interconnect network comprises depositing a metal layer on a major surface of the backplane and then patterning the metal layer into a first backplane electrically connected to a first terminal of the solar cell and a second backplane electrically connected to a second terminal of the solar cell.

51. The method of claim 50, wherein depositing the metal layer on the major surface is preceded by forming an electrically insulating release layer on the major surface, and wherein patterning the metal layer is followed by a step of selectively removing portions of the electrically insulating release layer extending between the first backplane and a major surface of the backplane.

52. An optoelectronic device, comprising:

a first substrate of a first material having at least a first conductive via therein extending between first and second opposing surfaces of the first substrate;

a second substrate of a second material different from the first material on the first substrate, the second substrate comprising a solar cell having a light receiving surface thereon and first and second terminals electrically connected to first and second regions in the solar cell; and

a first conductive film on the light receiving surface, the first conductive film extending from a first terminal of the solar cell to the first conductive via.

53. The optoelectronic device of claim 52, wherein the first conductive film extends from a first terminal of the solar cell onto the first surface of the first substrate.

54. The optoelectronic device of claim 52, wherein the solar cell is a compound semiconductor solar cell.

55. The optoelectronic device of claim 52, wherein the first and second regions in the solar cell are semiconductor regions having opposite conductivity types.

56. The optoelectronic device of claim 52, further comprising:

a second conductive via extending between the first and second opposing surfaces of the first substrate; and

a second conductive film extending from a second terminal of the solar cell to the second conductive via.

57. An optoelectronic device, comprising:

a first substrate of a first material having at least a first conductive structure therein extending between first and second opposing surfaces of the first substrate;

a second substrate of a second material different from the first material on the first substrate, the second substrate comprising a solar cell having a light receiving surface thereon and first and second terminals electrically connected to first and second regions in the solar cell; and

a first conductive film on the light receiving surface, the first conductive film extending from a first terminal of the solar cell to the first conductive structure.

58. A concentrator-type photovoltaic module comprising:

a miniature solar cell;

a front plate holding a series of short focal length primary optical lenses;

a secondary concentrator optical element that provides concentrated sunlight onto the miniature solar cell; and

a monolithic backplane, supported by the backplane, providing a means for dissipating heat and electrically interconnecting a series of said miniature solar cells.

59. The concentrator photovoltaic module of claim 58, wherein the micro-solar cells are thinner than 20 μm.

60. The concentrator-type photovoltaic module of claim 58, wherein the front plate and the primary optical lens are fabricated as a single piece.

61. The concentrator-type photovoltaic module of claim 58, wherein the front plate and the primary optical lens are made of glass.

62. The concentrator-type photovoltaic module of claim 58, wherein the primary optical lens is molded or laminated onto a bottom surface of the front plate.

63. The concentrator-type photovoltaic module of claim 58, wherein the primary optical lens is a plano-convex lens.

64. The concentrator-type photovoltaic module of claim 58, wherein the back sheet has a thickness of less than 10 x 10^-6mK^-1The coefficient of thermal expansion of (a).

65. The concentrator photovoltaic module of claim 58, wherein the back sheet is made of glass.

66. The concentrator photovoltaic module of claim 58, wherein the monolithic base plate is made of copper.

67. The concentrator photovoltaic module of claim 58, wherein the monolithic backplane is thinner than 51 μm.

68. The concentrator-type photovoltaic module of claim 58, wherein the primary and secondary lenses provide a combination of the following characteristics:

a geometric concentration equal to or higher than 1000 times;

an optical efficiency higher than 80%; and

wider than an acceptance angle of ± 1 degree.

69. A concentrator-type photovoltaic module comprising:

a front plate holding a series of short focal length primary optical lenses;

a series of surface mount receivers having an interposer board, wherein a membrane interconnect structure is located on top of the interposer board and a downward vertical conductive via extends through the interposer board, wherein the downward vertical conductive via is connected to an output pad on the bottom of the interposer board;

a micro solar cell having terminals transfer printed on the interposer board, wherein the terminals are in contact with the film interconnect structure on the top of the interposer board;

a sub-concentrator type optical element providing concentrated sunlight onto the micro solar cell; and

a monolithic backplane, supported by the backplane, provides a means for dissipating heat and electrically interconnecting a series of receivers.

70. The concentrator-type photovoltaic module of claim 69, wherein the primary and secondary lenses provide a combination of the following characteristics:

a geometric concentration equal to or higher than 1000 times;

an optical efficiency higher than 80%; and

wider than an acceptance angle of ± 1 degree.

71. The concentrator photovoltaic module of claim 69, wherein the interposer board is made of an aluminum compound.

72. The concentrator photovoltaic module of claim 69, wherein the monolithic base plate is made of copper.

73. The concentrator photovoltaic module of claim 69, wherein the back sheet is made of glass.

74. The concentrator photovoltaic module of claim 69, wherein the backplane is selectively patterned.

75. The concentrator-type photovoltaic module of claim 69, wherein the backplane is partially released from the backplane.

76. The concentrator photovoltaic module of claim 69, wherein the backplane has a metal layer selectively patterned and lifted onto the back side of the backplane.

77. The concentrator-type photovoltaic module of claim 69, wherein the back sheet has a thickness of less than 10 x 10^-6mK^-1The coefficient of thermal expansion of (a).

78. The concentrator photovoltaic module of claim 69, wherein the monolithic base plate is thinner than 51 μm.

79. The concentrator photovoltaic module of claim 69, wherein the secondary concentrator optical element homogenizes incident electromagnetic radiation.

80. The concentrator photovoltaic module of claim 69, further comprising a self-centering support structure on the micro solar cells configured to align a respective one of the secondary concentrator optical elements with a respective micro solar cell.

81. A leadless sub-receiver for concentrator-type optoelectronic systems, comprising:

a compound semiconductor solar cell attached to an upwardly facing surface of a sheet having a different composition, wherein the solar cell has at least two electrical terminals;

conductive film interconnect structures on the upward-facing surface of the plate that establish electrical connections with the solar cells, wherein at least one of the film interconnect structures establishes electrical connections with terminals on the upward-facing surface of the solar cells; and

a conductive structure establishing an electrical connection between a structure on an upward facing surface of the board and a structure on a downward facing surface of the board.

82. The leadless sub-receiver of claim 81, wherein the sub-receiver is a separate smaller portion of a receiver comprised of one or more solar cells and an optional secondary optical element that accepts concentrated sunlight and incorporates means for thermal and electrical energy transfer.

83. The leadless sub-receiver of claim 81, wherein the plate has a different composition selected from a group of materials including, but not limited to, aluminum oxide, aluminum nitride, silicon, aluminum, steel, and beryllium oxide.

84. The leadless sub-receiver of claim 81, wherein the conductive structure establishing electrical connection between the structure on the upward-facing surface of the plate and the structure on the downward-facing surface of the plate is a conductive via fill material.

85. The leadless sub-receiver of claim 81, wherein the conductive structure establishing electrical connection between the structure on the upward-facing surface of the plate and the structure on the downward-facing surface of the plate is a laterally positioned conductor.

86. The leadless sub-receiver of claim 81, wherein the structure on the downward facing surface of the plate is a conductive pad.

87. A leadless sub-receiver having sloped sidewalls for concentrator-type optoelectronic systems, the leadless sub-receiver comprising:

a compound semiconductor solar cell attached to an upwardly facing surface of a sheet having a different composition, wherein the solar cell has at least two electrical terminals;

conductive film interconnect structures on the upward-facing surface of the plate that establish electrical connections with the solar cells, wherein at least one of the film interconnect structures establishes electrical connections with terminals on the upward-facing surface of the solar cells; and

a conductive structure establishing an electrical connection between a structure on an upward facing surface of the board and a structure on a downward facing surface of the board.

88. The leadless sub-receiver of claim 87, wherein the electrical connection between structures on the upward facing surface of the plate and structures on the downward facing surface of the plate is through vias passing through the plate.

89. The leadless sub-receiver of claim 87, wherein the electrical connection between structures on an upward-facing surface of the plate and structures on a downward-facing surface of the plate is achieved through a membrane interconnect structure.

90. A leadless sub-receiver for concentrator-type optoelectronic systems, comprising:

one or more compound semiconductor solar cells attached to an upwardly facing surface of a sheet having a different composition, wherein the solar cells have at least two electrical terminals;

an optical element having a support structure for concentrating sunlight onto the solar cell to concentrate and homogenize incident electromagnetic radiation;

conductive film interconnect structures on the upwardly facing surface of the panel that establish electrical connections with each of the solar cells, wherein at least one of the film interconnect structures establishes electrical connections with terminals on the upwardly facing surface of each of the solar cells; and

a conductive structure establishing an electrical connection between a structure on an upward facing surface of the board and a structure on a downward facing surface of the board.

91. The leadless sub-receiver of claim 90, wherein the plate has a different composition selected from a group of materials including, but not limited to, aluminum oxide, aluminum nitride, silicon, aluminum, steel, and beryllium oxide.

92. The leadless sub-receiver of claim 90, wherein the conductive structure that establishes an electrical connection between the structure on the upward-facing surface of the plate and the structure on the downward-facing surface of the plate is a conductive via fill material.

93. The leadless sub-receiver of claim 90, wherein the optical element is a lens.

94. The leadless sub-receiver of claim 90, wherein the optical element comprises a light bucket.

95. The leadless sub-receiver of claim 90, wherein the conductive structure establishing an electrical connection between a structure on the upward-facing surface of the plate and a structure on the downward-facing surface of the plate is a laterally positioned conductor.

96. The leadless sub-receiver of claim 90, wherein the structure on the downward facing surface of the plate is a conductive pad.

97. The leadless sub-receiver of claim 90, wherein the plate comprises a bypass diode.

98. The leadless sub-receiver of claim 90, wherein the conductive film interconnected with the upwardly facing surface of the plate of electrical connection of the solar cell is electrically insulated from at least one of the electrical terminals of the compound semiconductor solar cell by an insulating film material.

99. The leadless sub-receiver of claim 98, wherein the insulating film material is an anti-reflective coating.

100. A method of forming a leadless sub-receiver for a concentrator-type optoelectronic system, comprising:

forming a board substrate having a first surface thereon;

printing a compound semiconductor solar cell onto the first surface of the board substrate, the compound semiconductor comprising at least a first terminal located on a light receiving surface;

forming a film interconnect structure extending from a first terminal on the light-receiving surface of the compound semiconductor solar cell to the first surface of the plate substrate; and

forming a conductive structure connecting a portion of the film interconnect structure disposed on the first surface of the board substrate to a structure on a second surface of the board substrate.

101. A method of assembling a concentrator photovoltaic module, comprising:

forming a series of solar cells at spaced apart locations on a first surface of a first substrate;

patterning conductive interconnect structures on terminals of the series of solar cells and on the first surface;

separating the first substrate into a plurality of sub-receivers having respective solar cells thereon; and

attaching the plurality of sub-receivers to a backplane having a monolithic backplane thereon, the backplane being electrically connected with the conductive interconnect structure and the terminals of the series of solar cells.

102. The method of claim 101, further comprising testing the series of solar cells on the first substrate in parallel prior to dividing the first substrate into a plurality of sub-receivers.

103. The method of claim 101, further comprising testing the series of solar cells on the first substrate prior to dividing the first substrate into a plurality of sub-receivers.

104. The method of claim 101, wherein the attaching comprises attaching the plurality of sub-receptacles to the monolithic base plate using a solder reflow process that bonds the sub-receptacles to the monolithic base plate.

105. The method of claim 101, wherein the patterning is followed by:

forming a self-centering lens support on the series of solar cells; and

sealing a spherical secondary lens to the self-centering lens support such that light received by each of the solar cells passes through a respective spherical secondary lens.

106. The method of claim 105, wherein the forming a self-centering lens support comprises forming a self-centering lens support on the series of solar cells and the conductive interconnect structure.

107. The method of claim 105, wherein said forming a self-centering lens support comprises forming a sealing ring concentrically arranged with respect to a corresponding self-centering lens support.

108. The method of claim 105, wherein the sealing of the spherical secondary lens to the self-centering lens support is performed simultaneously with the attaching of the plurality of sub-receivers to the backplate.

109. The method of claim 108, wherein the attaching comprises attaching the plurality of sub-receptacles to the monolithic base plate using a solder reflow process that bonds the sub-receptacles to the monolithic base plate.