Abstract: A low cost concentrating photovoltaic system includes a condenser system having refractive or reflective optics and a photovoltaic module having one or more thin film solar cells. The thin film solar cells may be a-Si, CdTe, Cu(InGa)Se2, organic solar cell or dye sensitized solar cells. The condenser system may be a flat, cylindrical or hemispherical Fresnel lens, a parabolic reflector, a compound parabolic concentrator, a reflective V-trough, or a combination thereof. The condenser system has a concentration ratio of about 10 to 100 or higher. No tracking system is needed in many examples, or a simple one-axis tracking may be used. In one example, the condenser system uses a hemispherical Fresnel lens which focuses sunlight onto a hemispherical focal surface, and one thin film solar cell (mounted on a tracking unit) or multiple cells (without tracking) are disposed on the hemispherical focal surface of the Fresnel lens.

Abstract: A solar energy concentrating system with high light collection efficiency includes a light concentrating unit, a light homogenizing unit and photovoltaic modules. The light concentrating unit includes a parabolic reflector and an ellipsoidal reflector which are coaxial and confocal. The light homogenizing unit includes an infrared filter and a hollow spherical reflector with a hole in its surface. When the system is under illumination, light is concentrated by the light concentrating unit through the hole in the spherical reflector surface and reflected by the inner surface of the spherical reflector onto the photovoltaic modules. The infrared filter covers the hole in the spherical reflector surface and reduces the heat in the photovoltaic modules under concentrated light. The combination of the parabolic reflector and the ellipsoidal reflector obtain highly concentrated light, and the hollow spherical reflector ensures light uniformity on the photovoltaic modules and light utilization efficiency.

Abstract: A method for fabricating thin film solar cells for a concentrated photovoltaic system uses three shadow masks. The first mask, used to deposit a back contact layer, has multiple horizontal and vertical lines defining columns and rows of cells, and multiple tabs each located in a cell along a center of a vertical border. The second mask, used to deposit a CIGS absorption layer, a window layer and a transparent contact layer, is similar to the first mask except the tabs are located along the opposite vertical border of the cells. The third mask, used to deposit a metal grid layer, has multiple bus bar openings and finger openings. Each bus bar opening is located along a horizontal center line of a cell and overlaps the second tab of a neighboring cell. The cells in a horizontal row are connected in series, forming a linear solar receiver.

Abstract: A solar energy concentrating system with high light collection efficiency includes a light concentrating unit, a light homogenizing unit and photovoltaic modules. The light concentrating unit includes a parabolic reflector and an ellipsoidal reflector which are coaxial and confocal. The light homogenizing unit includes an infrared filter and a hollow spherical reflector with a hole in its surface. When the system is under illumination, light is concentrated by the light concentrating unit through the hole in the spherical reflector surface and reflected by the inner surface of the spherical reflector onto the photovoltaic modules. The infrared filter covers the hole in the spherical reflector surface and reduces the heat in the photovoltaic modules under concentrated light. The combination of the parabolic reflector and the ellipsoidal reflector obtain highly concentrated light, and the hollow spherical reflector ensures light uniformity on the photovoltaic modules and light utilization efficiency.

Abstract: A concentrating photovoltaic system includes a condenser system and photovoltaic modules. The condenser system includes a quasi-Fresnel concave lens coated with an antireflection film and a reflector coated with a reflective film. The reflector is located between the quasi-Fresnel concave lens and the PV modules. A high refractive index optical resin is filled between the quasi-Fresnel concave lens and the photovoltaic modules. The quasi-Fresnel concave lens has a flat or hemispherical structure; the reflector can be placed horizontally, or at an angle to form a light condensing funnel.

Abstract: An in-line multi-stage physical vapor deposition chamber is disclosed. The deposition chamber includes a cylindrical shaped main body, multiple dividers disposed within the main body and extending in radial directions to divide the interior space of the main body into multiple fan shaped zones, and a cylindrical shaped substrate holder disposed coaxially with the main body. The substrate holder is rotatable around a central axis, and individual substrates or a continuous flexible substrate is mounted on the substrate holder parallel to the central axis. Multiple metal source holders are disposed on the cylindrical sidewall of the main body in at least some of zones for mounting metal sources. Some zones are provided with heating mechanisms for heating the substrate. A load-lock chamber is connected to the main body for loading and unloading substrates into and from a first zone.

Abstract: A method for fabricating thin film solar cells for a concentrated photovoltaic system uses three shadow masks. The first mask, used to deposit a back contact layer, has multiple horizontal and vertical lines defining columns and rows of cells, and multiple tabs each located in a cell along a center of a vertical border. The second mask, used to deposit a CIGS absorption layer, a window layer and a transparent contact layer, is similar to the first mask except the tabs are located along the opposite vertical border of the cells. The third mask, used to deposit a metal grid layer, has multiple bus bar openings and finger openings. Each bus bar opening is located along a horizontal center line of a cell and overlaps the second tab of a neighboring cell. The cells in a horizontal row are connected in series, forming a linear solar receiver.

Abstract: A low cost concentrating photovoltaic system includes a condenser system having refractive or reflective optics and a photovoltaic module having one or more thin film solar cells. The thin film solar cells may be a-Si, CdTe, Cu(InGa)Se2, organic solar cell or dye sensitized solar cells. The condenser system may be a flat, cylindrical or hemispherical Fresnel lens, a parabolic reflector, a compound parabolic concentrator, a reflective V-trough, or a combination thereof. The condenser system has a concentration ratio of about 10 to 100 or higher. No tracking system is needed in many examples, or a simple one-axis tracking may be used. In one example, the condenser system uses a hemispherical Fresnel lens which focuses sunlight onto a hemispherical focal surface, and one thin film solar cell (mounted on a tracking unit) or multiple cells (without tracking) are disposed on the hemispherical focal surface of the Fresnel lens.

Abstract: A solar energy concentrating system with high light collection efficiency includes a light concentrating unit, a light homogenizing unit and photovoltaic modules. The light concentrating unit includes a parabolic reflector and an ellipsoidal reflector which are coaxial and confocal. The light homogenizing unit includes an infrared filter and a hollow spherical reflector with a hole in its surface. When the system is under illumination, light is concentrated by the light concentrating unit through the hole in the spherical reflector surface and reflected by the inner surface of the spherical reflector onto the photovoltaic modules. The infrared filter covers the hole in the spherical reflector surface and reduces the heat in the photovoltaic modules under concentrated light. The combination of the parabolic reflector and the ellipsoidal reflector obtain highly concentrated light, and the hollow spherical reflector ensures light uniformity on the photovoltaic modules and light utilization efficiency.

Abstract: Native Group IV semiconductor thin films formed from coating substrates using formulations of Group IV nanoparticles are described. Such native Group IV semiconductor thin films leverage the vast historical knowledge of Group IV semiconductor materials and at the same time exploit the advantages of Group IV semiconductor nanoparticles for producing novel thin films which may be readily integrated into a number of devices.

Abstract: A method of forming a densified nanoparticle thin film is disclosed. The method includes positioning a substrate in a first chamber; and depositing a nanoparticle ink, the nanoparticle ink including a set of Group IV semiconductor particles and a solvent. The method also includes heating the nanoparticle ink to a first temperature between about 30° C. and about 300° C., and for a first time period between about 1 minute and about 60 minutes, wherein the solvent is substantially removed, and a porous compact is formed; and positioning the substrate in a second chamber, the second chamber having a pressure of between about 1×10?7 Torr and about 1×10?4 Torr. The method further includes depositing on the porous compact a dielectric material; wherein the densified nanoparticle thin film is formed.

Abstract: A set of nanoparticles is disclosed. Each nanoparticle of the set of nanoparticles is comprised of a set of Group IV atoms arranged in a substantially spherical configuration. Each nanoparticle of the set of nanoparticles further having a sphericity of between about 1.0 and about 2.0; a diameter of between about 4 nm and about 100 nm; and a sintering temperature less than a melting temperature of the set of Group IV atoms.

Abstract: The present invention provides photoactive materials that include inorganic nanostructures comprising a Group IV semiconductor in combination with electron-transporting, conjugated small molecules, carbon nanostructures, or both. The carbon nanostructures or conjugated small molecules may be selected such that the inorganic nanostructures and the carbon nanostructures (and/or the small molecules) exhibit a type II band offset. The photovoltaic materials are well-suited for use as the active layer in photoactive devices, including photovoltaic devices, photoconductors, and photodetectors.

Abstract: A method of forming a densified nanoparticle thin film in a chamber is disclosed. The method includes positioning a substrate in the chamber; and depositing a nanoparticle ink, the nanoparticle ink including a set of Group IV semiconductor particles and a solvent. The method also includes heating the nanoparticle ink to a first temperature between about 30° C. and about 300° C., and for a first time period between about 1 minute and about 60 minutes, wherein the solvent is substantially removed, and a porous compact is formed. The method further includes exposing the porous compact to an HF vapor for a second time period of between about 2 minutes and about 20 minutes, and heating the porous compact for a second temperature of between about 25° C. and about 60° C.; and heating the porous compact to a third temperature between about 100° C. and about 1000° C., and for a third time period of between about 5 minutes and about 10 hours; wherein the densified nanoparticle thin film is formed.

Abstract: A device for generating a plurality of electron-hole pairs from a photon is disclosed. The device includes a substrate, a first electrode formed above the substrate, and a first doped Group IV nanoparticle thin film deposited on the first electrode. The device further includes an intrinsic layer deposited on the first doped Group IV nanoparticle thin film, wherein the intrinsic layer includes a matrix material with a melting temperature T1, wherein T1 is greater than about 300° C., and a set of quantum confined nanoparticles each with a melting temperature T2, wherein T2 is less than about 900° C., wherein the melting temperature T1 is less than the melting temperature T2.

Abstract: A method of forming a densified nanoparticle thin film is disclosed. The method includes positioning a substrate in a first chamber; and depositing a nanoparticle ink, the nanoparticle ink including a set of Group IV semiconductor particles and a solvent. The method also includes heating the nanoparticle ink to a first temperature between about 30° C. and about 300° C., and for a first time period between about 1 minute and about 60 minutes, wherein the solvent is substantially removed, and a porous compact is formed; and positioning the substrate in a second chamber, the second chamber having a pressure of between about 1×10?7 Torr and about 1×10?4 Torr. The method further includes depositing on the porous compact a dielectric material; wherein the densified nanoparticle thin film is formed.

Abstract: A set of nanoparticles is disclosed. Each nanoparticle of the set of nanoparticles is comprised of a set of Group IV atoms arranged in a substantially spherical configuration. Each nanoparticle of the set of nanoparticles further having a sphericity of between about 1.0 and about 2.0; a diameter of between about 4 nm and about 100 nm; and a sintering temperature less than a melting temperature of the set of Group IV atoms.

Abstract: A method of forming a densified nanoparticle thin film in a chamber is disclosed. The method includes positioning a substrate in the chamber; and depositing a nanoparticle ink, the nanoparticle ink including a set of Group IV semiconductor particles and a solvent. The method also includes heating the nanoparticle ink to a first temperature between about 30° C. and about 300° C., and for a first time period between about 1 minute and about 60 minutes, wherein the solvent is substantially removed, and a porous compact is formed. The method further includes exposing the porous compact to an HF vapor for a second time period of between about 2 minutes and about 20 minutes, and heating the porous compact for a second temperature of between about 25° C. and about 60° C.; and heating the porous compact to a third temperature between about 100° C. and about 1000° C., and for a third time period of between about 5 minutes and about 10 hours; wherein the densified nanoparticle thin film is formed.

Abstract: A method of fabricating a densified nanoparticle thin film with a set of occluded pores in a chamber is disclosed. The method includes positioning a substrate in the chamber; and depositing a nanoparticle ink, the nanoparticle ink including a set of Group IV semiconductor particles and a solvent. The method further includes heating the nanoparticle ink to a first temperature between about 30° C. and about 300° C., and for a first time period between about 5 minutes and about 60 minutes, wherein the solvent is substantially removed, and a porous compact with a set of pores is formed. The method also includes heating the porous compact to a second temperature between about 300° C. and about 900° C., and for a second time period of between about 5 minutes and about 15 minutes, and flowing a precursor gas into the chamber at a partial pressure between about 0.

Abstract: A device for generating electricity from solar radiation is disclosed. The device includes a substrate; an insulating layer formed above the substrate; and a first electrode formed above the insulating layer. The device also includes a first doped Group IV nanoparticle thin film deposited on the first electrode; and a second doped Group IV nanoparticle thin film deposited on the first doped Group IV nanoparticle thin film. The device further includes a third doped Group IV nanoparticle thin film deposited on the second doped Group IV nanoparticle thin film; a fourth doped Group IV nanoparticle thin film deposited on the third doped Group IV nanoparticle thin film; and, a second electrode formed on the fourth doped Group IV nanoparticle thin film. Wherein, when solar radiation is applied to the fourth doped Group IV nanoparticle thin film, an electrical current is produced.