Abstract: The radiation-selective absorber coating, in particular for an absorber tube of a parabolic trough collector, includes a reflective layer which is reflective in the infrared range, at least one barrier layer arranged below the reflective layer, at least one absorption layer arranged above the reflective layer, an antireflection layer arranged above the absorption layer and at least one adhesion-enhancing layer arranged between the barrier layer and the reflective layer. The adhesion-enhancing layer preferably is a molybdenum layer, but can also be provided by a copper, titanium, titanium oxide, or silicon layer. The adhesion-enhancing layer preferably has a thickness of 5 to 50 nm.

Abstract: An absorber tube is provided that includes a metal tube, a glass sleeve tube surrounding the metal tube, and a glass-metal transition element is disposed on at least one end. The metal tube and the transition element can be moved relative to one another in the longitudinal direction and connected to one another by an expansion compensating device. An inner end of the expansion compensating device is fastened to an attachment element, which is connected to the transition element. An outer end of the expansion compensating device is fastened to the metal tube. An annular space section of the annular space is constructed between the transition and attachment elements. The attachment element has an annular disc on which the expansion compensating device is fastened. The absorber tube has at least one shielding device that has a first annular disc-shaped section disposed on at least one end in the annular space.

Abstract: An absorber tube is provided that has a central metal tube, a glass cladding tube, and a glass-metal transition element. The metal tube and the glass-metal transition element are connected to each other by an expansion compensation device such that they can be displaced relative to each other in the longitudinal direction. The expansion compensation device is arranged at least partially in an annular space between the metal tube and the glass-metal transition element. In the annular space, at least one shielding device is arranged, which has a first annular disc-shaped segment arranged at an axial distance in front of the end face and covers at least the connection region of the attachment element and the inner end of the expansion compensation device.

Abstract: An absorber tube, especially for solar collectors in solar thermal power plants with at least one collector mirror, is provided. The absorber tube includes a metal tube for supplying and heating a heat transfer medium, a sheath tube surrounding the metal tube to form an annular space that can be evacuated, a wall extending through the sheath tube and the metal tube to seal the annular space, and a getter material binding free hydrogen in the annular space. The absorber tube has a temperature variation device that changes the temperature of the getter material and the wall.

Abstract: A receiver system for a Fresnel solar plant is provided. The system includes an absorber tube defining a longitudinal direction and a mirror array that runs parallel to the longitudinal direction. The mirror array has a mirror-symmetrical curve profile having at least one top apex for concentrating light beams onto the absorber tube. The mirror array has ventilation holes in the region of the apex.

Abstract: A crystalline solar cell is provided that includes a front-sided n-doped area and a rear-sided p-doped area, a front-sided contact, a rear-sided contact and at least one front-sided first layer made from SiN. In order to reduce degradation of the parallel resistance, a second layer made of at least one material selected from the group SiN, SiOx, Al2Ox, SiOxNy: Hz, a-Si:H, TiOx or containing said type of material is disposed between the first layer and the n-doped area and is then doped for forming imperfections.

Abstract: A method for producing a dopant profile is provided. The method includes starting from a surface of a wafer-shaped semiconductor component by introducing dopant atoms into the semiconductor component. The dopant-containing layer is produced on or in a region of the surface in order to produce a provisional first dopant profile and then a plurality of semiconductor components having a corresponding layer is subjected to heat treatment on top of one another in the form of a stack in order to produce a second dopant profile having a greater depth in comparison to the first dopant profile.

Abstract: An absorber tube is provided that includes a metal tube, a glass sleeve tube surrounding the metal tube, and a glass-metal transition element is disposed on at least one end. The metal tube and the transition element can be moved relative to one another in the longitudinal direction and connected to one another by an expansion compensating device. An inner end of the expansion compensating device is fastened to an attachment element, which is connected to the transition element. An outer end of the expansion compensating device is fastened to the metal tube. An annular space section of the annular space is constructed between the transition and attachment elements. The attachment element has an annular disc on which the expansion compensating device is fastened. The absorber tube has at least one shielding device that has a first annular disc-shaped section disposed on at least one end in the annular space.

Abstract: A method for producing a crystalline solar cell having a p-doped silicon substrate with an n-doped region on the front side and also at least one antireflection layer is provided. The method includes uniformly applying a solution containing phosphoric acid to the entire front-side surface of the solar cell, forming phosphosilicate glass in a first thermal treatment step applied to the solar cell, and, in the first thermal treatment step or a subsequent thermal treatment step, forming silicon-containing precipitates near the surface with a homogeneous or substantially homogeneous surface coverage in a layer on the front-side surface of the substrate in the range of between 5% and 100%.

Abstract: A method is provided for forming a dopant profile based on a surface of a wafer-like semiconductor component with phosphorus as a dopant. The method includes the steps of applying a phosphorus dopant source onto the surface, forming a first dopant profile with the dopant source that is present on the surface, removing the dopant source, and forming a second dopant profile that has a greater depth in comparison to the first dopant profile. In order to form an optimized dopant profile, the dopant source is removed after forming the first dopant profile, and precipitates that are crystallized selectively on or in the surface from the precipitates SixPy and SixPyOz are removed.

Abstract: A solar cell is provided that includes a semiconductor substrate with a front-side contact and a rear-side contact. The front-side contact includes contact fingers running parallel to one another and at least one busbar running transversely with respect thereto. A connector runs along the busbar and is cohesively connected thereto. In order to avoid cracking in the event of forces acting on the connector, the busbar includes sections that have soldering edges and over which the connector extends.

Abstract: A method for producing an MWT-PERC solar cell is provided, in which openings in the substrate of the solar cell have contact passages and emitter regions that are present on the back side of the solar cell are completely removed outside the contact passages and a dielectric layer is applied on the back side, whereby a paste, which does not act in an electrically contacting manner opposite the substrate, is used for the contact passages.

Abstract: The invention relates to an improved process for the production of a sugar alcohol from the corresponding sugar through catalytic hydrogenation. Especially, the invention relates to a process for reducing the interference of sugar-derived aldonic acids in the hydrogenation process by adjusting the hydrogenation conditions so that the activity of the catalyst is maintained. In one embodiment of the invention, the process of the invention is carried out by adjusting the hydrogenation temperature by starting the hydrogenation at a lower temperature and then gradually rising the temperature to the final hydrogenation temperature. In another embodiment of the invention, the process of the invention is carried out by adding small-molecular monocarboxylic acids to the hydrogenation solution.

Abstract: The invention concerns a method and an apparatus for the application of solder onto a work piece, wherein the solder is soldered on at a soldering temperature TL and subject to the influence of ultrasound. In order to be able to solder without difficulties the solder onto work pieces that exhibit sensitivity to breakage it is proposed that the solder is heated, is applied to the work piece that is supported in particular in a spring-mounted manner, and is soldered-on subject to the influence of ultrasound.

Abstract: A method for producing contacts made of electrically conductive material on solar cells is provided. The method includes applying a dopant source to at least one face of a substrate; forming phosphosilicate glass by diffusing dopant into the substrate in a first thermal step; locally applying laser radiation to the substrate in regions in which the electrically conductive material is to be applied in order to form the electrically conductive contact; measuring the layer resistivity developed in the surface region of the substrate on the dopant source side; applying the electrically conductive material to the lasered areas; measuring the specific contact resistance between the lasered area and the electrically conductive material; determining a pulse energy density range of the laser beam from the measured values; applying laser radiation having a pulse energy density within the determined pulse energy density range.

Abstract: A semiconductor component including a first layer (10) of a semiconductor material as a substrate, a second layer (12) running on said first layer (10), and at least two intermediate layers (14, 16) made of the materials of the first and second layers running between the first and second layer, where the first intermediate layer (16) facing the second layer (12) may contain a eutectic mixture (18) made of the materials of the first and second layers. The invention is also directed to an electroconductive contact (15, 15a, 15b) forming an electroconductive connection to the first layer and originating at or running through the second layer, as well as to a method for producing the metal-semiconductor contact.

Abstract: A method is provided for forming a dopant profile based on a surface of a wafer-like semiconductor component with phosphorus as a dopant. The method includes the steps of applying a phosphorus dopant source onto the surface, forming a first dopant profile with the dopant source that is present on the surface, removing the dopant source, and forming a second dopant profile that has a greater depth in comparison to the first dopant profile. In order to form an optimized dopant profile, the dopant source is removed after forming the first dopant profile, and precipitates that are crystallized selectively on or in the surface from the precipitates SixPy and SixPyOz are removed.

Abstract: A method for chemically treating a disc-shaped substrate having a bottom surface, a top surface and side surfaces by contacting a process medium that is fluid-chemically active with at least the bottom surface of the substrate. The substrate is moved relative to the process medium while forming a triple line between the substrate, the substrate medium and the atmosphere surrounding the substrate and medium. In order to chemically remove errors, particularly in the side surfaces, relative motion should be carried out while avoiding a contacting of the process medium with the top surface of the substrate, where the triple line is formed at a desired height of the side surface facing away from the process medium flow side in relation to the relative motion between the substrate and the process medium.

Abstract: The radiation-selective absorber coating for absorber tubes of parabolic trough collectors includes two or more barrier layers (24a, 24b); an infrared reflective layer (21) on the barrier layers (24a, 24b); at least one cermet absorption layer (22) above the infrared reflective layer (21) and an antireflection layer (23) above the at least one cermet absorption layer (22). The two or more barrier layers (24a, 24b) include a first barrier layer (24a) of thermally produced oxide and a second barrier layer (24b) arranged above it. The second barrier layer (24b) is a cermet material including at least one oxide compound and at least one metal. The oxide compound is aluminium oxide, silicon oxide, nickel oxide and/or chromium oxide. The metal is molybdenum, nickel, tungsten and/or vanadium. The invention also includes an absorber tube with the absorber coating on it.

Abstract: A method for the wet-chemical etching of a highly doped silicon layer in an etching solution is provided. The method includes using, as an etching solution so as to perform etching homogeneously, an HF-containing etching solution containing at least one oxidizing agent selected from the group of peroxodisulfates, peroxomonosulfates, and hydrogen peroxide.