Abstract: A photovoltaic (PV) device with improved blue response. The PV device includes a silicon substrate with an emitter layer on a light receiving side. The emitter layer has a low opant level such that it has sheet resistance of 90 to 170 ohm/sq. Anti-reflection in the PV device is provided solely by a nano-structured or black silicon surface on the light-receiving surface, through which the emitter is formed by diffusion. The nano structures of the black silicon are formed in a manner that does not result in gold or another high-recombination metal being left in the black silicon such as with metal-assisted etching using silver. The black silicon is further processed to widen these pores so as to provide larger nanostructures with lateral dimensions in the range of 65 to 150 nanometers so as to reduce surface area and also to etch away a highly doped portion of the emitter.

Abstract: A solar cell is disclosed. The solar cell includes a first conductive region positioned at a front surface of a semiconductor substrate and containing impurities of a first conductivity type or a second conductivity type, a second conductive region positioned at a back surface of the semiconductor substrate and containing impurities of a conductivity type opposite a conductivity type of impurities of the first conductive region, a first electrode positioned on the front surface of the semiconductor substrate and connected to the first conductive region, and a second electrode positioned on the back surface of the semiconductor substrate and connected to the second conductive region. Each of the first and second electrodes includes metal particles and a glass frit.

Abstract: The present invention provides a method for depositing an organic-inorganic perovskite, the method comprising the step of depositing a perovskite precursor solution comprising one or more organic cation, wherein said precursor solution preferably deposited by inkjet printing. The method is particularly useful in the manufacture of perovskite solar cells. For depositing the perovskite, a perovskite precursor solution or ink is preferably used, which comprises an organic cation carrying an anchoring group, such as 5-ammonium valeric acid. Surprisingly, the presence of the latter compound renders the precursor solutions stable and suitable for inkjet printing.

Abstract: A photovoltaic device includes a photoactive material comprising a perovskite material and an interfacial layer comprising a cross-linked polymer that comprises a fullerene or fullerene derivative, a cross-linking agent, and one or more polymers selected from the group consisting of polystyrene, [6,6]-phenyl-C61-butyric acid methyl ester, poly(4-vinylphenol), [6,6]-phenyl-C61-butyric acid, and any combination thereof.

Abstract: A photodetector includes a photodetecting region in a semiconductor substrate, and a reflector extending at least partially along a sidewall of the photodetecting region in the semiconductor substrate. The reflector includes an air gap defined in the semiconductor substrate. The reflector allows use of thinner germanium for the photodetecting region. The air gap may have a variety of internal features to direct electromagnetic radiation towards the photodetecting region.

Abstract: A solar cell element is provided with a semiconductor substrate, a passivation layer, and an electrode. The semiconductor substrate has a first surface and a second surface that is positioned on a back side of the first surface. The passivation layer is positioned on the second surface of the semiconductor substrate. The electrode is positioned on the passivation layer and positioned in the state of being electrically connected to the semiconductor substrate. The electrode includes a linear electrode part that is positioned along a peripheral edge of the semiconductor substrate when the semiconductor substrate is seen from the second surface side in plane perspective view, and is positioned in the state of penetrating the passivation layer in a thickness direction.

Abstract: A solar cell includes an n-type silicon substrate having a first main surface and a second main surface, an n-type first semiconductor layer disposed above the first main surface, a first intrinsic semiconductor layer disposed between the first main surface and the first semiconductor layer, a p-type second semiconductor layer disposed on the second main surface, and a second intrinsic semiconductor layer disposed between the second main surface and the second semiconductor layer. An oxygen concentration at an interface between the silicon substrate and the second intrinsic semiconductor layer is lower than an oxygen concentration at an interface between the silicon substrate and the second intrinsic semiconductor layer. An oxygen concentration at an interface between the second intrinsic semiconductor layer and the second semiconductor layer is higher than an oxygen concentration at an interface between the first intrinsic semiconductor layer and the first semiconductor layer.

Abstract: A solar cell is provided. The solar cell at least includes a semiconductor layer and a plurality of passivation layers provided on a back surface of the semiconductor layer. The passivation layers include a first silicon oxynitride film layer having a first refractive index, a second silicon oxynitride film layer having a second refractive index and provided on a surface of the first silicon oxynitride film layer, and a silicon nitride film layer having a third refractive index and provided on a surface of the second silicon oxynitride film layer.

Abstract: Provided are a negative electrode active material for a secondary battery, which suppresses a dispersal phenomenon of a negative electrode active material during charging/discharging by controlling a lattice mismatch ratio of an amorphous matrix layer to a silicon layer in a silicon-based negative electrode active material.

Abstract: The present application discloses devices that include a perovskite layer, a first layer that includes an oxide, and an interface layer, where the interface layer is positioned between the first layer and the perovskite layer, the interface layer is in physical contact with both the first layer and the perovskite layer, and the interface layer consists essentially of the oxide.

Abstract: A system and a conversion element for power conversion. The power conversion system includes a power conversion device which produces electric power upon illumination and includes a light conversion device which down-converts and up-converts a radiant source of energy into a specific energy spectrum for the illumination of the power conversion device. The conversion element includes a first plurality of particles which upon radiation from a first radiation source radiate at a higher energy than the first radiation source, and includes a second plurality of particles which upon radiation from the first radiation source radiate at a lower energy than the first radiation source. At least one of the first plurality of particles and the second plurality of particles can be at least partially metal coated.

Abstract: A method for manufacturing a solar cell, includes forming an oxide layer on first surface of a single crystalline silicon substrate; forming a poly crystalline silicon layer doped with a first dopant having a first conductive type on the oxide layer; diffusing a second dopant having a second conductive type opposite to the first conductive type into a second surface of the single crystalline silicon substrate thereby forming a diffusion region; forming a first passivation layer on the poly crystalline silicon layer; forming a second passivation layer on the diffusion region; forming a first electrode connected to the poly crystalline silicon layer by printing a first paste on the first passivation layer and firing through; forming a second electrode connected to the diffusion region by printing a second paste on the second passivation layer and firing through.

Abstract: High germanium percentage (40 atomic percent or greater) silicon germanium (SiGe) graded buffer layers are provided in which stacking fault formation and dislocation defect density are drastically suppressed. Notably, a lattice matched heterogeneous semiconductor material interlayer of Ga(As1-yPy) wherein y is from 0 to 1 is formed between each of the SiGe layers of the graded buffer layer to reduce the propagation of threading arm dislocation to the surface and inhibit the formation of stacking faults in each subsequent SiGe layer, and therewith drastically reduce the surface defect density.

Abstract: A method for increasing the speed of aerosol jet assisted printing a layered perovskite structure comprises applying a PEDOT:PSS layer to a substrate; applying an aerosol mist containing methylammonium iodide and lead iodide, with or without additives, atop the PEDOT:PSS layer with an aerosol jet nozzle; and holding the structure to form a methylammonium lead iodide (CH3NH3PbI3) perovskite thin film layer. The substrate may be an ITO glass or plastic substrate, and the PEDOT:PSS layer may be applied by a process selected from spin-coating, inkjet-printing, slot-die-coating, aerosol jet printing, physical vapor deposition, chemical vapor deposition, and electrochemical deposition. The aerosol mist is generated from a single ink comprising all the constituents of methylammonium lead iodide either dissolved or suspended in one or more compatible solvents or co-solvents. The holding of the CH3NH3PbI3 layer may be performed at about 25-120° C. or lower for 96 hours or less.

Abstract: A solar cell includes a semiconductor substrate containing impurities of a first conductive type; a tunnel layer positioned on the semiconductor substrate; an emitter region positioned on the tunnel layer and containing impurities of a second conductive type opposite the first conductive type; a dopant layer positioned on the emitter region and formed of a dielectric material containing impurities of the second conductive type; a first electrode connected to the semiconductor substrate; and a second electrode configured to pass through the dopant layer, and connected to the emitter region.

Abstract: An electron source system utilizing photon enhanced thermionic emission to create a source of well controlled electrons for injection into a series of lenses so that the beam can be fashioned to meet the particular specification for a given use is disclosed. Because of the recent increased understanding and characterization of the bandgap in certain materials, a simplified system can now be realized to overcome the potential barrier at the surface. With this system, only low electric fields with moderate temperatures (˜500 ° C.) are required. The resulting system enables much easier focusing of the electron beam because the random component of the energy of the electrons is much lower than that of a conventional system.

Abstract: Provided are a thin-film solar cell module structure and a method of manufacturing the same.

Abstract: A solar cell includes a first layer having a first-layer lattice parameter, a second layer having a second-layer lattice parameter different from the first-layer lattice parameter, wherein the second layer includes a photoactive second-layer material; and a third layer having a third-layer lattice parameter different from the second-layer lattice parameter, wherein the third layer includes a photoactive third-layer material. A transparent buffer layer extends between and contacts the second layer and the third layer and has a buffer-layer lattice parameter that varies with increasing distance from the second layer toward the third layer, so as to lattice match to the second layer and to the third layer. There may be additional subcell layers and buffer layers in the solar cell.

Abstract: The present disclosure describes solution methods for manufacturing perovskite halide films for use in solar cells. The methods include the use of additives that facilitate the formation of transitory, intermediate films that are later transformed into the final target perovskite halide films, such that the final films provide improved physical characteristics and operational performance.

Abstract: A 2-terminal multi-junction solar cell having a thin film of metal halide semiconductor as the top solar-cell material and crystalline silicon as the bottom solar-cell material. In the illustrative embodiment, the top solar-cell material is a perovskite of the form AM(IxH1-x)3, where A is a cation, preferably methylammonium (CH3NH3), formamidinium ([R2N—CH?NR2]+), or cesium; M is metal, preferably Pb, Sn, Ge; H is a halide, preferably Br or Cl; and x=iodine fraction, in the range of 0 to 1, inclusive. The integration of the two solar-cell materials is enabled by the use of a tunnel junction composed of indirect band-gap material.

Abstract: Embodiments of the invention include a luminescent structure including an InxZnyP core, wherein 0<y/x<10, and wherein the core comprises an alloy including both In and Zn, and a shell disposed on a surface of the core, wherein a difference between a lattice constant of the shell and a lattice constant of the core relative to the lattice constant of the shell is less than 1%.

Abstract: A vehicle glazing includes on its surface to be exposed to the exterior atmosphere, at least in a zone not wiped by the windscreen wipers, a mineral oxide layer of 0.1 to 20 ?m thickness, 30 to 90% of the volume of which consists of 20 to 300 nm open pores that are distributed uniformly throughout the thickness of the layer, and almost all of which are connected to one another, the internal and external surface of the layer being functionalized with a compound containing a perfluoroalkyl or alkyl functional group, then saturated with a hydrophobic oil that impregnates the functionalized porous layer and forms a film on the surface thereof, the at least one zone being located facing a detecting device such as an anti-collision/obstacle-detecting/security video camera, or similar, placed in the interior of the vehicle, in particular on the face of the glazing.

Abstract: A stacked integrated multi-junction solar cell, having a first subcell, whereby the first subcell has a layer of an InGaP compound with a first lattice constant and a first band gap energy, and the thickness of the layer is greater than 100 nm and the layer is formed as part of an emitter and/or as part of the base and/or as part of the space charge region lying between the emitter and base, and a second subcell with a second lattice constant and a second band gap energy, and a third subcell with a third lattice constant and a third band gap energy, and a fourth subcell with a fourth lattice constant and a fourth band gap energy, and a region with a wafer bond is formed between two subcells.

Abstract: Four conjugated copolymers with a donor/acceptor architecture including 4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b?]dithiophene as the donor structural unit and benzo[2,1,3]thiodiazole fragments with varying degrees of fluorination have been synthesized and characterized. It has been shown that the HOMO levels were decreased after the fluorine substitution. The field-effect charge carrier mobility was similar for all polymers with less than an order of magnitude difference between different acceptor units.

Abstract: A process for producing conductive pastes for forming solar cell electrodes, including a step of measuring binding energies of oxygen in a glass frit by X-ray photoelectron spectroscopy, a step of selecting a glass frit providing an X-ray photoelectron spectrum representing binding energies of oxygen in which the signal intensity of a peak with a peak top at a range from 529 eV to less than 531 eV has a proportion of 40% or more relative to the total of signal intensities from 526 eV to 536 eV, and a step of mixing together a conductive powder, the glass frit and an organic vehicle.

Abstract: A method for aerosol-jet printing a layered perovskite structure by applying a PEDOT:PSS layer to a substrate; applying a layer of lead iodide (PbI2) to the PEDOT:PSS layer; and applying an aerosol mist of methylammonium iodide (CH3NH3I) atop the PbI2 layer with an aerosol-jet nozzle to form a CH3NH3PbI3 perovskite film layer. The substrate may be an ITO glass substrate, and the PEDOT:PSS layer may be applied by a process selected from spin-coating, inkjet-printing, slot-die-coating, aerosol-jet printing, physical vapor deposition, chemical vapor deposition, and electrochemical deposition. The PbI2 layer may be applied by a process selected from spin-coating, aerosol-jet printing, inkjet-printing, slot-die-coating, physical vapor deposition, chemical vapor deposition, and electrochemical deposition, and the PbI2 for application to the PEDOT:PSS layer may be in a solution of DMF, DMSO, ?-butyrolactone, or a combination thereof.

Abstract: The present disclosure relates ionic liquids which are used as lubricants for medical devices. In some aspects, the ionic liquids of the present disclosure can exhibit antimicrobial or host cell integrative activity or a combination of functionalities. In some aspects, the present disclosure also provides devices coated with the ionic liquid.

Abstract: A method of manufacturing a solar cell according to an embodiment includes the steps of: forming an emitter layer by ion-implanting a first conductive type dopant to a first surface of a semiconductor substrate; and forming a back surface field layer by ion-implanting a second conductive type dopant to a second surface of the semiconductor substrate. When an additional dopant is a dopant other than the first and second conductive type dopants, an amount of the additional dopant doped during the forming the back surface field layer is larger than an amount of the additional dopant doped during the forming the emitter layer.

Abstract: Disclosed herein is a method for doping a substrate, comprising disposing a coating of a composition comprising a copolymer, a dopant precursor and a solvent on a substrate; where the copolymer is capable of phase segregating and embedding the dopant precursor while in solution; and annealing the substrate at a temperature of 750 to 1300° C. for 0.1 second to 24 hours to diffuse the dopant into the substrate. Disclosed herein too is a semiconductor substrate comprising embedded dopant domains of diameter 3 to 30 nanometers; where the domains comprise Group 13 or Group 15 atoms, wherein the embedded spherical domains are located within 30 nanometers of the substrate surface.

Abstract: An atom, molecule, atomic layer, or molecular layer is adhered to a carbon nanotube surface, or the surface is doped with the atom, molecule, atomic layer, or molecular layer, to form a deep localized level so that an exciton is localized. Alternatively, an atom, molecule, inorganic or organic substance of an atomic or molecular layer, a metal, a semiconductor, or an insulator is absorbed to, deposited on, or encapsulated in the carbon tube inside surface to make permittivity of the portion undergoing the absorption, deposition, or encapsulation higher than that of a clean portion free of the absorption, deposition, or encapsulation so that binding energy of the exciton in the clean portion is high, or reduce a band gap of the portion undergoing the absorption, deposition, or encapsulation so that the exciton is confined and localized in the clean portion or the position undergoing the absorption, deposition, or encapsulation.

Abstract: A photoelectric conversion device of an embodiment includes, in sequence: a substrate; a first electrode; a photoelectric conversion layer containing a perovskite compound and a solvent; and a second electrode. The perovskite compound has a composition represented by a composition formula of ABX3. The A represents at least one selected from a monovalent cation of a metal element and a monovalent cation of an amine compound. The B represents a bivalent cation of a metal element. The X represents a monovalent anion of a halogen element. The number of molecules of the solvent with respect to one crystal lattice of the perovskite compound ranges from 0.004 to 0.5.

Abstract: The invention relates to a method for producing a solar cell (1) from crystalline semiconductor material, wherein a first doping region (5) is formed by means of ion implantation (S2) of a first dopant in a first surface (3a) of a semiconductor substrate (3), and a second doping region (7) is formed by means of ion implantation (S3) or thermal indiffusion of a second dopant in the second surface (3b) of the semiconductor substrate. After the doping of the second surface, a cap (9b) acting as an outdiffusion barrier for the second dopant is applied and an annealing step (S4) is subsequently carried out.

Abstract: A solar cell can include a substrate of a first conductive type; an emitter region which is positioned at a front surface of the substrate and has a second conductive type different from the first conductive type; a back surface field region which is positioned at a back surface opposite the front surface of the substrate; a front passivation region including a plurality of layers which are sequentially positioned on the emitter region; a back passivation region including a plurality of layers which are sequentially positioned on the back surface field region; a front electrode part which passes through the front passivation region and is connected to the emitter region, wherein the front electrode part comprises a plurality of front electrodes that are apart from each other and a front bus bar connecting the plurality of front electrodes; a back electrode part which passes through the back passivation region and is connected to the back surface field region, wherein the back electrode part comprises a plural

Abstract: Intercalation pastes for use with semiconductor devices are disclosed. The pastes contain precious metal particles, intercalating particles, and an organic vehicle and can be used to improve the material properties of metal particle layers. Specific formulations have been developed to be screen-printed directly onto a dried metal particle layer and fired to make a fired multilayer stack. The fired multilayer stack can be tailored to create a solderable surface, high mechanical strength, and low contact resistance. In some embodiments, the fired multilayer stack can etch through a dielectric layer to improve adhesion to a substrate. Such pastes can be used to increase the efficiency of silicon solar cells, specifically multi- and mono-crystalline silicon back-surface field (BSF), and passivated emitter and rear contact (PERC) photovoltaic cells. Other applications include integrated circuits and more broadly, electronic devices.

Abstract: A transistor including an oxide semiconductor layer can have stable electrical characteristics. In addition, a highly reliable semiconductor device including the transistor is provided. A semiconductor device includes a multi-layer film including an oxide layer and an oxide semiconductor layer, a gate insulating film in contact with the multi-layer film, and a gate electrode overlapping with the multi-layer film with the gate insulating film provided therebetween. In the semiconductor device, the oxide semiconductor layer contains indium, the oxide semiconductor layer is in contact with the oxide layer, and the oxide layer contains indium and has a larger energy gap than the oxide semiconductor layer.

Abstract: A transistor including an oxide semiconductor layer can have stable electrical characteristics. In addition, a highly reliable semiconductor device including the transistor is provided. A semiconductor device includes a multi-layer film including an oxide layer and an oxide semiconductor layer, a gate insulating film in contact with the multi-layer film, and a gate electrode overlapping with the multi-layer film with the gate insulating film provided therebetween. In the semiconductor device, the oxide semiconductor layer contains indium, the oxide semiconductor layer is in contact with the oxide layer, and the oxide layer contains indium and has a larger energy gap than the oxide semiconductor layer.

Abstract: A silicon material useful as a negative electrode active material is provided. The silicon material has a band gap within a range of greater than 1.1 eV and not greater than 1.7 eV. A secondary battery in which this silicon material is used as a negative electrode active material has improved initial efficiency.

Abstract: Solar cell arrangement of a thin film solar cell array on a substrate; each solar cell being layered with a bottom electrode, a photovoltaic active layer, a top electrode and an insulating layer. A first trench and a second trench parallel to the first trench at a first side, separate a first solar cell and an adjacent second solar cell. The first and second trenches are filled with insulating material. The first trench extends to the substrate. The second trench extends into the photovoltaic active layer below the top electrode. A third trench extending to the bottom electrode is between the first and second trench. A fourth trench extending to the top electrode is at a second side of the first trench. The third and fourth trench are filled with conductive material. A conductive bridge connects the third trench and the fourth trench across the first trench.

Abstract: A method for manufacturing a solar cell includes forming a passivation layer on a rear surface of a substrate of a first conductivity type; forming connecting electrodes having a plurality of electrical contacts that are in contact with the rear surface of the substrate by using a first paste for a first temperature firing on portions of the passivation layer; and forming a rear electrode layer by using a second paste for a second temperature firing on the passivation layer and the plurality of electrical contacts, wherein a temperature of the second temperature firing is lower than a temperature of the first temperature firing.

Abstract: The invention provides an optoelectronic device comprising a porous material, which porous material comprises a semiconductor comprising a perovskite. The porous material may comprise a porous perovskite. Thus, the porous material may be a perovskite material which is itself porous. Additionally or alternatively, the porous material may comprise a porous dielectric scaffold material, such as alumina, and a coating disposed on a surface thereof, which coating comprises the semiconductor comprising the perovskite. Thus, in some embodiments the porosity arises from the dielectric scaffold rather than from the perovskite itself. The porous material is usually infiltrated by a charge transporting material such as a hole conductor, a liquid electrolyte, or an electron conductor. The invention further provides the use of the porous material as a semiconductor in an optoelectronic device. Further provided is the use of the porous material as a photosensitizing, semiconducting material in an optoelectronic device.

Abstract: Solar cell fabrication using laser patterning of ion-implanted etch-resistant layers, and the resulting solar cells, are described. In an example, a back contact solar cell includes a maximum concentration of the approximately Gaussian distribution of P-type dopants approximately in the center of each of segmented P-type emitter regions between first and second sides of each of the segmented P-type emitter regions.

Abstract: A photovoltaic device is presented. The photovoltaic device includes a layer stack; and an absorber layer is disposed on the layer stack. The absorber layer includes selenium, and an atomic concentration of selenium varies non-linearly across a thickness of the absorber layer. A method of making a photovoltaic device is also presented.

Abstract: Disclosed herein is a conductive paste for forming a conductive film, including: (A) a conductive powder; (B) as a first additive, at least one selected from a first group consisting of Se, Te, a compound containing Se, and a compound containing Te; (C) as a second additive, a compound containing at least one element selected from a second group consisting of V, Nb, Ta, Sb, Bi, Mn, Ge, Si, and W; (D) glass frit; (E) an organic binder; and (F) a solvent.

Abstract: The invention relates to an electro-conductive paste comprising coarse SiO2 particles in the preparation of electrodes in solar cells, particularly in the preparation of electrodes in MWT solar cells, particularly in the preparation of the metal wrap through, or plug, electrode in such solar cells. In particular, the invention relates to a solar cell precursor, a process for preparing a solar cells, a solar cell and a module comprising solar cells. The invention relates to a solar cell precursor at least comprising as precursor parts: i) a wafer (101) with at least one hole (315) with a Si surface (113); ii) an electro-conductive paste (105) at least comprising as paste constituents: a) metallic particles; b) an inorganic reaction system; c) an organic vehicle; and d) inorganic oxide particles having no glass transition temperature below about 750° C. or a glass transition temperature which is at least about 50° C.

Abstract: A method for fabricating a solar cell includes providing a first substrate with at least one protruding element on the first substrate. The method removes a portion of a lower conducting layer located on the first substrate, wherein the removed portion of the lower conducting layer is located near the at least one protruding element. The method removes a first portion of an active layer located on the lower conducting layer. The method deposits an upper conducting layer on the active layer, wherein the conducting layer covers the at least one protruding element. The method removes a portion of the upper conducting layer, wherein the removed portion of the upper conducting is located near the at least one protruding element.

Abstract: A method for manufacturing a polycrystalline silicon ingot includes steps of: a) melting a silicon material in a container disposed in a thermal field to form a molten silicon; b) controlling the thermal field to provide heat to the molten silicon from above the container and to solidify a portion of the molten silicon contacting a base part and at least a portion of a wall part proximate to the base part of the container to form a solid silicon crystalline isolation layer; and c) controlling the thermal field to continuously provide heat to the rest of the molten silicon from above the container and to solidify the rest of the molten silicon gradually from a bottom to a top of the rest of the molten silicon to form a polycrystalline silicon ingot.

Abstract: A layered perovskite structure comprising a substrate having an upper surface and a lower surface; and a layer of a perovskite film on the upper surface. A passivating layer may be applied to the upper surface of the substrate to which the perovskite film is attached. The passivating layer comprises at least one a chalcogenide-containing species with the general chemical formula (E3E4)N(E1E2)N?C?X where any one of E1, E2, E3 and E4 is independently selected from C1-C15 organic substituents comprising from 0 to 15 heteroatoms or hydrogen, and X is S, Se or Te, thiourea, thioacetamide, selenoacetamide, selenourea, H2S, H2Se, H2Te, or LXH wherein L is a Cn organic substituent comprising heteroatoms and X?S, Se, or Te. The substrate comprises PEDOT:PSS, and may further comprise a layered glass/ITO/PEDOT:PSS structure. A passivating layer is applied to the PEDOT:PSS layer, and a top electrode may be applied over the perovskite film.

Abstract: A passivation layer is deposited on a first portion of a region of the solar cell. A grid line is deposited on a second portion of the region. The passivation layer is annealed to drive chemical species from the passivation layer to deactivate an electrical activity of a dopant in the first portion of the region of the solar cell.

Abstract: The present disclosure generally relates to a solar cell device that a first Bragg reflector disposed below a first solar cell and a second Bragg reflector disposed below the first Bragg reflector, wherein the first solar cell comprises a dilute nitride composition and has a first bandgap, wherein the first Bragg reflector is operable to reflect a first range of radiation wavelengths back into the first solar cell and the second Bragg reflector is operable to reflect a third range of wavelengths back into the first solar cell, and the first Bragg reflector and the second Bragg reflector are operable to cool the solar cell device by reflecting a second range of radiation wavelengths that are outside the photogeneration wavelength range of the first solar cell or that are weakly absorbed by the first solar cell.

Abstract: A method of preparing an iron-implanted semiconductor wafer for use in surface photovoltage iron mapping and other evaluation techniques. A semiconductor wafer is implanted with iron through the at least two different regions of the front surface of the semiconductor at different iron implantation densities, and the iron-implanted semiconductor wafer is annealed at a temperature and duration sufficient to diffuse implanted iron into the bulk region of the semiconductor wafer.