Abstract: The highly mismatched alloy Zn1-yMnyOxTe1-x, 0?y<1 and 0<x<1 and other Group II-IV-Oxygen implanted alloys have been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of extended states located within the band gap of the Zn1-yMnyTe host. With multiple band gaps that fall within the solar energy spectrum, Zn1-yMnyOxTe1-x is a material perfectly satisfying the conditions for single-junction photovoltaics with the potential for power conversion efficiencies surpassing 50%.

Abstract: Methods are disclosed of fabricating a solar cell system. A solar cell is formed over a substrate. The substrate is attached to a carrier. A translucent or transparent protective cover is overlaid over the solar cell to produce the solar cell system, which is deployed onto an exterior of a building.

Abstract: A method of forming a doped Group IBIIIAVIA absorber layer for solar cells by reacting a a metallic precursor layer with a dopant structure. The metallic precursor layer including Group IB and Group IIIA materials such as Cu, Ga and In are deposited on a base. The dopant structure is formed on the metallic precursor layer, wherein the dopant structure includes a stack of one or more Group VIA material layers such as Se layers and one or more a dopant material layers such as Na.

Abstract: A thin film solar cell module of see-through type and a method of fabricating the same are provided. First, bi-directional openings are formed in the transparent electrode material layer to avoid problems that affect the production yield such as short-circuit resulted by the high-temperature laser scribing process. Moreover, the thin film solar cell module of see-through type has openings that expose the transparent substrate without covering the transparent electrode material layer to increase the transmittance of the cells.

Abstract: CIGS absorber layers fabricated using coated semiconducting nanoparticles and/or quantum dots are disclosed. Core nanoparticles and/or quantum dots containing one or more elements from group IB and/or IIIA and/or VIA may be coated with one or more layers containing elements group IB, IIIA or VIA. Using nanoparticles with a defined surface area, a layer thickness could be tuned to give the proper stoichiometric ratio, and/or crystal phase, and/or size, and/or shape. The coated nanoparticles could then be placed in a dispersant for use as an ink, paste, or paint. By appropriate coating of the core nanoparticles, the resulting coated nanoparticles can have the desired elements intermixed within the size scale of the nanoparticle, while the phase can be controlled by tuning the stochiometry, and the stoichiometry of the coated nanoparticle may be tuned by controlling the thickness of the coating(s).

Abstract: Apparatus and Method for Optimizing the Efficiency of Germanium Junctions in Multi-Junction Solar Cells. In a preferred embodiment, an indium gallium phosphide (InGaP) nucleation layer is disposed between the germanium (Ge) substrate and the overlying dual-junction epilayers for controlling the diffusion depth of the n-doping in the germanium junction. Specifically, by acting as a diffusion barrier to arsenic (As) contained in the overlying epilayers and as a source of n-type dopant for forming the germanium junction, the nucleation layer enables the growth time and temperature in the epilayer device process to be minimized without compromising the integrity of the dual-junction epilayer structure. This in turn allows the arsenic diffusion into the germanium substrate to be optimally controlled by varying the thickness of the nucleation layer.

Abstract: A photovoltaic device utilizing a gain means and an amplification means to intake and convert incident light/photons to greater intensities of highly coherent and monochromatic photons whereby said photons are passed to a resonating means and absorption means, allowing for said photons to be absorbed with increased conversion efficiency.

Abstract: In an embodiment, one reinforced substrate for use in a photovoltaic device includes a polymer base material and a reinforcing structure bonded with the base material. The reinforced substrate presents a surface in a condition that is made-ready for deposition of thin film layers of the photovoltaic device. A thin film photovoltaic device includes the reinforced substrate, a back contact layer formed on the surface of the reinforced substrate, and a solar absorber layer formed on the back contact layer. A plurality of thin film photovoltaic devices may be formed on a common reinforced substrate. A process of producing a reinforced substrate includes combining a fluid base material and a fiber reinforcing structure to form an impregnated fiber reinforcement. The impregnated fiber reinforcement is cured to form the reinforced substrate, and the reinforced substrate is annealed.

Abstract: Apparatus and Method for Optimizing the Efficiency of Germanium Junctions in Multi-Junction Solar Cells. In a preferred embodiment, an indium gallium phosphide (InGaP) nucleation layer is disposed between the germanium (Ge) substrate and the overlying dual-junction epilayers for controlling the diffusion depth of the n-doping in the germanium junction. Specifically, by acting as a diffusion barrier to arsenic (As) contained in the overlying epilayers and as a source of n-type dopant for forming the germanium junction, the nucleation layer enables the growth time and temperature in the epilayer device process to be minimized without compromising the integrity of the dual-junction epilayer structure. This in turn allows the arsenic diffusion into the germanium substrate to be optimally controlled by varying the thickness of the nucleation layer.

Abstract: The present invention relates generally to the field of photovoltaics and more specifically to manufacturing thin-film solar cells using a thermal process. Specifically, a method is disclosed to manufacture a CIGS solar cell by an in-situ junction formation process.

Abstract: A multi-junction solar cell device (10) is provided. The multi-junction solar cell device (10) comprises either two or three active solar cells connected in series in a monolithic structure. The multi-junction device (10) comprises a bottom active cell (20) having a single-crystal silicon substrate base and an emitter layer (23). The multi-junction device (10) further comprises one or two subsequent active cells each having a base layer (32) and an emitter layer (23) with interconnecting tunnel junctions between each active cell. At least one layer that forms each of the top and middle active cells is composed of a single-crystal III-V semiconductor alloy that is substantially lattice-matched to the silicon substrate (22). The polarity of the active p-n junction cells is either p-on-n or n-on-p.

Abstract: A photovoltaic cell exhibiting an overall conversion efficiency of at least 9.0% is prepared from a copper-indium-gallium-diselenide thin film. The thin film is prepared by simultaneously electroplating copper, indium, gallium, and selenium onto a substrate using a buffered electro-deposition bath. The electrodeposition is followed by adding indium to adjust the final stoichiometry of the thin film.

Abstract: A solar cell has an active semiconductor structure and a back electrical contact overlying and contacting an active semiconductor structure back side. A front electrical contact is applied overlying and contacting the active semiconductor structure front side. The front electrical contact has multiple layers including a titanium layer overlying and contacting the active semiconductor structure front side, a diffusion layer overlying and contacting the titanium layer, a barrier layer overlying and contacting the diffusion layer, and a joining layer overlying and contacting the barrier layer. The front electrical contact may be applied by sequentially vacuum depositing the titanium layer, the diffusion layer, the barrier layer, and the joining layer in a vacuum deposition apparatus in a single pumpdown from ambient pressure. A front electrical lead is affixed overlying and contacting an attachment pad region of the front electrical contact.

Abstract: The present invention relates to light-weight thin-film photovoltaic cells, methods for making cells, modules made from cells, and methods for making modules from cells. The invention teaches a manner in which individual cells may be bonded to one another, eliminating the need for an additional support substrate and interconnecting leads, thus reducing the overall weight and thickness of individual cells and modules of the cells.

Abstract: The invention relates to a method for constructing a layer structure on an especially fragile flat substrate. In order for thin, fragile flat substrates to be able to be subjected to refinement or construction of semiconductor components, a process is proposed with the steps: Applying an inorganic ceramic phase to the fragile substrate and subsequent heat treatment for hardening and sintering the inorganic ceramic material.

Abstract: An alloy having a large band gap range is used in a multijunction solar cell to enhance utilization of the solar energy spectrum. In one embodiment, the alloy is In1?xGaxN having an energy bandgap range of approximately 0.7 eV to 3.4 eV, providing a good match to the solar energy spectrum. Multiple junctions having different bandgaps are stacked to form a solar cell. Each junction may have different bandgaps (realized by varying the alloy composition), and therefore be responsive to different parts of the spectrum. The junctions are stacked in such a manner that some bands of light pass through upper junctions to lower junctions that are responsive to such bands.

Abstract: A photovoltaic or thermophotovoltaic device includes a diode formed by p-type material and n-type material joined at a p-n junction and including a depletion region adjacent to said p-n junction, and a quantum barrier disposed near or in the depletion region of the p-n junction so as to decrease device reverse saturation current density while maintaining device short circuit current density. In one embodiment, the quantum barrier is disposed on the n-type material side of the p-n junction and decreases the reverse saturation current density due to electrons while in another, the barrier is disposed on the p-type material side of the p-n junction and decreases the reverse saturation current density due to holes. In another embodiment, both types of quantum barriers are used.

Abstract: A process for making a thin film ZnO/Cu(InGa)Se2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se2 layer on the metal back contact on the glass substrate to a temperature range between about 100° C. to about 250° C.; subjecting the heated layer of Cu(InGa)Se2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se2.

Abstract: A two-junction solar cell has a bottom solar cell junction of crystalline silicon, and a top solar cell junction of gallium phosphide. A three (or more) junction solar cell has bottom solar cell junctions of silicon, and a top solar cell junction of gallium phosphide. The resulting solar cells exhibit improved extended temperature operation.

Abstract: Systems and methods are described for synthesis of films, coatings or layers using templates. A method includes locating a template within at least one of a first precursor layer that is coupled to a first substrate and a second precursor layer that is coupled to a second substrate; forming a composition layer; and moving the first substrate relative to the second substrate, wherein the composition layer remains coupled to the second substrate.

Abstract: A method of disordering a layer of an optoelectronic device including; growing a plurality of lower layers; introducing an isoelectronic surfactant; growing a layer; allowing the surfactant to desorb; and growing subsequent layers all performed at a low pressure of 25 torr.

Abstract: The present invention provides a solar cell comprising a substrate, a first buffer layer disposed above the base layer, a second buffer layer disposed above the first buffer layer, a first boron compound layer disposed above the second buffer layer, a second boron compound layer disposed above the first compound layer, and a window layer disposed above the second compound layer, wherein the first compound layer comprises a first type of doping, wherein the second compound layer comprises a second type of doping, wherein the second buffer layer comprises a higher energy bandgap than the first compound layer, and wherein the first buffer layer and the second buffer layer permit a boron content in the first compound layer and the second compound layer to be greater than 3 %.

Abstract: A method of reducing propagation of threading dislocations into active areas of an optoelectronic device having a III–V material system includes growing a metamorphic buffer region in the presence of an isoelectronic surfactant. A first buffer layer may be lattice matched to an adjacent substrate and a second buffer layer may be lattice matched to device layers disposed upon the second buffer layer. Moreover, multiple metamorphic buffer layers fabricated in this manner may be used in a single given device allowing multiple layers to have their band gaps and lattice constants independently selected from those of the rest of the device.

Abstract: A photovoltaic cell or other optoelectronic device having a wide-bandgap semiconductor used in the window layer. This wider bandgap is achieved by using a semiconductor composition that is not lattice-matched to the cell layer directly beneath it and/or to the growth substrate. The wider bandgap of the window layer increases the transmission of short wavelength light into the emitter and base layers of the photovoltaic cell. This in turn increases the current generation in the photovoltaic cell. Additionally, the wider bandgap of the lattice mismatched window layer inhibits minority carrier injection and recombination in the window layer.

Abstract: The present invention is directed to systems and methods for protecting a solar cell. The solar cell includes first solar cell portion. The first solar cell portion includes at least one junction and at least one solar cell contact on a backside of the first solar cell portion. At least one bypass diode portion is epitaxially grown on the first solar cell portion. The bypass diode has at least one contact. An interconnect couples the solar cell contact to the diode contact.

Abstract: Nanocomposite photovoltaic devices are provided that generally include semiconductor nanocrystals as at least a portion of a photoactive layer. Photovoltaic devices and other layered devices that comprise core-shell nanostructures and/or two populations of nanostructures, where the nanostructures are not necessarily part of a nanocomposite, are also features of the invention. Varied architectures for such devices are also provided including flexible and rigid architectures, planar and non-planar architectures and the like, as are systems incorporating such devices, and methods and systems for fabricating such devices. Compositions comprising two populations of nanostructures of different materials are also a feature of the invention.

Abstract: Nanocomposite photovoltaic devices are provided that generally include semiconductor nanocrystals as at least a portion of a photoactive layer. Photovoltaic devices and other layered devices that comprise core-shell nanostructures and/or two populations of nanostructures, where the nanostructures are not necessarily part of a nanocomposite, are also features of the invention. Varied architectures for such devices are also provided including flexible and rigid architectures, planar and non-planar architectures and the like, as are systems incorporating such devices, and methods and systems for fabricating such devices. Compositions comprising two populations of nanostructures of different materials are also a feature of the invention.

Abstract: Method and system for converting solar energy into electrical energy utilizing serially coupled multijunction-type photovoltaic cells in conjunction with a form of spectral cooling. The latter cooling is carried out by removing ineffective solar energy components from impinging concentrated light, inter alia, through the utilization of dichroics or the conversion of ineffective solar energy components to effective energy components by means of luminescence, phosphorescence, or fluorescence. Ineffective solar energy components are described as those exhibiting wavelengths outside the bandgap energy defined wavelength and an associated wavelength defined band of useful photon energy.

Abstract: A method and a multijunction solar device having a high band gap heterojunction middle solar cell are disclosed. In one embodiment, a triple-junction solar device includes bottom, middle, and top cells. The bottom cell has a germanium (Ge) substrate and a buffer layer, wherein the buffer layer is disposed over the Ge substrate. The middle cell contains a heterojunction structure, which further includes an emitter layer and a base layer that are disposed over the bottom cell. The top cell contains an emitter layer and a base layer disposed over the middle cell.

Abstract: GaAs substrates with compositionally graded buffer layers for matching lattice constants with high-Indium semiconductor materials such as quantum well infrared photoconductor devices and thermo photo voltaic devices are disclosed.

Abstract: Sulfur is used to improve the performance of CIGS devices prepared by the evaporation of a single source ZIS type compound to form a buffer layer on the CIGS. The sulfur may be evaporated, or contained in the ZIS type material, or both. Vacuum evaporation apparatus of many types useful in the practice of the invention are known in the art. Other methods of delivery, such as sputtering, or application of a thiourea solution, may be substituted for evaporation.

Abstract: Nanocomposite photovoltaic devices are provided that generally include semiconductor nanocrystals as at least a portion of a photoactive layer. Photovoltaic devices and other layered devices that comprise core-shell nanostructures and/or two populations of nanostructures, where the nanostructures are not necessarily part of a nanocomposite, are also features of the invention. Varied architectures for such devices are also provided including flexible and rigid architectures, planar and non-planar architectures and the like, as are systems incorporating such devices, and methods and systems for fabricating such devices. Compositions comprising two populations of nanostructures of different materials are also a feature of the invention.

Abstract: A solar cell having a multijunction solar cell structure with a bypass diode is disclosed. The bypass diode provides a reverse bias protection for the multijunction solar cell structure. In one embodiment, the multifunction solar cell structure includes a substrate, a bottom cell, a middle cell, a top cell, a bypass diode, a lateral conduction layer, and a shunt. The lateral conduction layer is deposited over the top cell. The bypass diode is deposited over the lateral conduction layer. One side of the shunt is connected to the substrate and another side of the shunt is connected to the lateral conduction layer. In another embodiment, the bypass diode contains an i-layer to enhance the diode performance.

Abstract: A CIS-based solar cell with a high conversion efficiency that has been reduced in cost by omitting a window layer is provided. The solar cell includes: a first layer having translucency and conductivity; and a p-type semiconductor layer disposed adjacent to the first layer, with a junction being formed by the first layer and the p-type semiconductor layer, wherein the p-type semiconductor layer includes a semiconductor with a chalcopyrite structure containing a group Ib element, a group IIIb element and a group VIb element, the first layer has a carrier density of 1019/cm3 or more, a band gap Eg1 (eV) of the first layer and a band gap Eg2 (eV) of the p-type semiconductor layer satisfy a relationship represented by the formula: Eg1>Eg2, and an electron affinity &khgr;1 (eV) of the first layer and an electron affinity &khgr;2 (eV) of the p-type semiconductor layer satisfy a relationship represented by the formula: 0≦(&khgr;2−&khgr;1)<0.5.

Abstract: A thin-film solar cell including a transparent electrode layer, a semiconductor photovoltaic conversion layer, a rear transparent electrode layer and a rear reflective metal layer, said layers being formed in this order on a transparent substrate, wherein the rear transparent electrode has a two-layer structure of an ITO or ZnO:Ga layer and a ZnO:Al layer formed in this order on the semiconductor photovoltaic conversion layer.

Abstract: There is disclosed herein a concentrating solar energy receiver comprising a primary parabolic reflector having a center and a high reflectivity surface on a concave side of the reflector and having a focal axis extending from the concave side of the reflector and passing through a focal point of the primary parabolic reflector; and a conversion module having a reception surface wherein the reception surface is spaced from the focal point by a predetermined distance and disposed to receive a predetermined cross section of radiant solar energy reflected from the concave side of the primary parabolic reflector for conversion to electrical energy in the conversion module. In one aspect, the conversion module includes a reception surface comprising a planar array of at least one photovoltaic solar cell. In another aspect, the conversion module includes a reception surface coupled to a thermal cycle engine. The mechanical output of the thermal cycle engine drives an electric generator.

Abstract: Isoelectronic co-doping of semiconductor compounds and alloys with deep acceptors and deep donors is used to decrease bandgap, to increase concentration of the dopant constituents in the resulting alloys, and to increase carrier mobilities lifetimes. Group III-V compounds and alloys, such as GaAs and GaP, are isoelectronically co-doped with, for example, N and Bi, to customize solar cells, thermal voltaic cells, light emitting diodes, photodetectors, and lasers on GaP, InP, GaAs, Ge, and Si substrates. Isoelectronically co-doped Group II-VI compounds and alloys are also included.

Abstract: On a surface of a GaAs substrate, layers to be a top cell are formed by epitaxial growth. On the top cell, layers to be a bottom cell are formed. Thereafter, on a surface of the bottom cell, a back surface electrode is formed. Thereafter, a glass plate is adhered to the back surface electrode by wax. Then, the GaAs substrate supported by the glass plate is dipped in an alkali solution, whereby the GaAs substrate is removed. Thereafter, a surface electrode is formed on the top cell. Finally the glass plate is separated from the back surface electrode. In this manner, a compound solar battery that improves efficiency of conversion to electric energy can be obtained.

Abstract: A photovoltaic cell exhibiting an overall conversion efficiency of at least 9.0% is prepared from a copper-indium-gallium-diselenide thin film. The thin film is prepared by simultaneously electroplating copper, indium, gallium, and selenium onto a substrate using a buffered electro-deposition bath. The electrodeposition is followed by adding indium to adjust the final stoichiometry of the thin film.

Abstract: The present invention provides a photovoltaic cell comprising a GaInP subcell comprising a disordered group-III sublattice, a Ga(In)As subcell disposed below the GaInP subcell, and a Ge substrate disposed below the Ga(In)As subcell comprising a surface misoriented from a (100) plane by an angle from about 8 degrees to about 40 degrees toward a nearest (111) plane.

Abstract: In an InGaP/InGaAs/Ge triple-junction solar cell, efficiency of a multijunction solar cell is improved by adjusting a ratio of an Al composition in an (Al)InGaP cell. According to a current-matching method in a multijunction solar cell, the ratio of the Al composition in an AlInGaP material for a top cell is adjusted in order to achieve matching between photocurrents generated in the top cell and a middle cell in the multijunction solar cell. Here, the multijunction solar cell uses as the top cell a solar cell-formed with the AlInGaP material and having a PN junction, uses as a middle cell a solar cell lattice-matched to the top cell, formed with an (In)GaAs(N) material and having a PN junction, and uses as a bottom cell a solar cell lattice-matched to the middle cell, formed with a Ge material and having a PN junction.

Abstract: A method of combining group III elements with group V elements that incorporates at least nitrogen from a nitrogen halide for use in semiconductors and in particular semiconductors in photovoltaic cells.

Abstract: Methods for formulating and depositing a sol-gel coating onto a surface of a solar cell to provide improved radiation damage resistance. The sol-gel contains a solvent, alkoxyzirconium and an organosilane, with an organic acid catalyst and optionally a surfactant. The sol-gel coating can be deposited by spraying and the sol-gel coating is cured. The invention reduces manufacturing steps and overall weight of the solar cell array.

Abstract: An alloy having a large band gap range is used in a multijunction solar cell to enhance utilization of the solar energy spectrum. In one embodiment, the alloy is In1-xGaxN having an energy bandgap range of approximately 0.7 eV to 3.4 eV, providing a good match to the solar energy spectrum. Multiple junctions having different bandgaps are stacked to form a solar cell. Each junction may have different bandgaps (realized by varying the alloy composition), and therefore be responsive to different parts of the spectrum. The junctions are stacked in such a manner that some bands of light pass through upper junctions to lower junctions that are responsive to such bands.

Abstract: Nanocomposite photovoltaic devices are provided that generally include semiconductor nanocrystals as at least a portion of a photoactive layer. Photovoltaic devices and other layered devices that comprise core-shell nanostructures and/or two populations of nanostructures, where the nanostructures are not necessarily part of a nanocomposite, are also features of the invention. Varied architectures for such devices are also provided including flexible and rigid architectures, planar and non-planar architectures and the like, as are systems incorporating such devices, and methods and systems for fabricating such devices. Compositions comprising two populations of nanostructures of different materials are also a feature of the invention.

Abstract: A method of reducing propagation of threading dislocations into active areas of an optoelectronic device having a III-V material system includes growing a metamorphic buffer region in the presence of an isoelectronic surfactant. A first buffer layer may be lattice matched to an adjacent substrate and a second buffer layer may be lattice matched to device layers disposed upon the second buffer layer. Moreover, multiple metamorphic buffer layers fabricated in this manner may be used in a single given device allowing multiple layers to have their band gaps and lattice constants independently selected from those of the rest of the device.

Abstract: A method of disordering a layer of an optoelectronic device including; growing a plurality of lower layers; introducing an isoelectronic surfactant; growing a layer; allowing the surfactant to desorb; and growing subsequent layers all performed at a low pressure of 25 torr.

Abstract: A photoelectric conversion element is disposed in each of a plurality of recesses of a support. Light reflected by the inside surface of the recess shines on the photoelectric conversion element. The photoelectric conversion element has an approximately spherical shape and has the following structure. The outer surface of a center-side n-type amorphous silicon (a-Si) layer is covered with a p-type amorphous SiC (a-SiC) layer having a wider optical band gap than a-Si does, whereby a pn junction is formed. A first conductor of the support is connected to the p-type a-SiC layer of the photoelectric conversion element at the bottom or its neighborhood of the recess. A second conductor, which is insulated from the first conductor by an insulator, of the support is connected to the n-type a-Si layer of the photoelectric conversion element.

Abstract: The present invention provides a solar cell comprising a substrate, a first buffer layer disposed above the base layer, a second buffer layer disposed above the first buffer layer, a first boron compound layer disposed above the second buffer layer, a second boron compound layer disposed above the first compound layer, and a window layer disposed above the second compound layer, wherein the first compound layer comprises a first type of doping, wherein the second compound layer comprises a second type of doping, wherein the second buffer layer comprises a higher energy bandgap than the first compound layer, and wherein the first buffer layer and the second buffer layer permit a boron content in the first compound layer and the second compound layer to be greater than 3%.

Abstract: A concentrating photovoltaic module is provided which provides a concentration in the range of about 500 to over 1,000 suns and a power range of a few kW to 50 kW. A plurality of such modules may be combined to form a power plant capable of generating over several hundred megaWatts. The concentrating photovoltaic module is based on a Photovoltaic Cavity Converter (PVCC) as an enabling technology for very high solar-to-electricity conversions. The use of a cavity containing a plurality of single junction solar cells of different energy bandgaps and simultaneous spectral splitting of the solar spectrum employs a lateral geometry in the spherical cavity (where the cell strings made of the single junction cells operate next to each other without mutual interference). The purpose of the cavity with a small aperture for the pre-focused solar radiation is to confine (trap) the photons so that they can be recycled effectively and used by the proper cells.