Abstract: A process for the combined production of methanol and ammonia, wherein a reactant stream includes carbon monoxide is supplied to a recovery assembly to obtain first and second hydrogen-containing streams, each having an increased molar proportion of hydrogen compared to the reactant stream. The recovery assembly includes a shift conversion in which the carbon monoxide of at least one carbon monoxide-containing stream is at least partially converted into hydrogen and carbon dioxide by reaction with steam to obtain a converted stream having hydrogen and carbon dioxide at least partially recycled to a hydrogen recovery from which the first and second hydrogen-containing streams are obtained. A nitrogen stream and, at least partially, the first hydrogen-containing stream are supplied to an ammonia reactor assembly for at least partial conversion into ammonia and, at least partially, the second hydrogen-containing stream is supplied to a methanol reactor assembly for at least partial conversion into the methanol.

Abstract: A process for the combined production of methanol and ammonia, wherein a reactant stream includes carbon monoxide is supplied to a recovery assembly to obtain first and second hydrogen-containing streams, each having an increased molar proportion of hydrogen compared to the reactant stream. The recovery assembly includes a shift conversion in which the carbon monoxide of at least one carbon monoxide-containing stream is at least partially converted into hydrogen and carbon dioxide by reaction with steam to obtain a converted stream having hydrogen and carbon dioxide at least partially recycled to a hydrogen recovery from which the first and second hydrogen-containing streams are obtained. A nitrogen stream and, at least partially, the first hydrogen-containing stream are supplied to an ammonia reactor assembly for at least partial conversion into ammonia and, at least partially, the second hydrogen-containing stream is supplied to a methanol reactor assembly for at least partial conversion into the methanol.

Abstract: The invention relates to a plant complex for steel production comprising a blast furnace for producing pig iron, a converter steel mill for producing crude steel and a gas-conducting system for gases that occur when producing the pig iron and/or producing the crude steel. According to the invention, the plant complex additionally has a chemical plant or biotechnological plant, connected to the gas-conducting system, and also energy storage for covering at least part of the electricity demand of the plant complex. Also the subject of the invention is a method for operating the plant complex.

Abstract: The invention relates to a plant complex for steel production comprising a blast furnace for producing pig iron, a converter steel mill for producing crude steel and a gas-conducting system for gases that occur when producing the pig iron and/or producing the crude steel. According to the invention, the plant complex additionally has a chemical plant or biotechnological plant, connected to the gas-conducting system, and also energy storage for covering at least part of the electricity demand of the plant complex. Also the subject of the invention is a method for operating the plant complex.

Abstract: A radiation-emitting semiconductor component has an improved radiation efficiency. The semiconductor component has a multilayer structure with an active layer for generating radiation within the multilayer structure and also a window having a first and a second main surface. The multi-layer structure adjoins the first main surface of the window. At least one recess, such as a trench or a pit, is formed in the window from the second main surface for the purpose of increasing the radiation efficiency. The recess preferably has a trapezoidal cross section tapering toward the first main surface and can be produced for example by sawing into the window.

Abstract: A process for structuring at least one layer as well as an electrical component with structures from the layer are described. The invention states a process to generate at least one structured layer (10A), wherein a mask structure (20) with a first (20A) and second structure (20B) is generated on a layer (10) which is present on a substrate (5). Through this mask structure (20), the first layer (20A) is transferred onto the layer (10) using isotropic structuring processes, and the second structure (20B) is transferred onto the layer (10) using anisotropic structuring processes. The process as per the invention permits the generation of two structures (20A, 20B) in at least a single layer while using a single mask structure.

Abstract: The invention states a process to generate at least one structured layer (10A), wherein a mask structure (20) with a first (20A) and second structure (20B) is generated on a layer (10) which is present on a substrate (5). Through this mask structure (20), the first layer (20A) is transferred onto the layer (10) using isotropic structuring processes, and the second structure (20B) is transferred onto the layer (10) using anisotropic structuring processes. The process as per the invention permits the generation of two structures (20A, 20B) in at least a single layer while using a single mask structure.

Abstract: A radiation-emitting semiconductor component has an improved radiation efficiency. The semiconductor component has a multilayer structure with an active layer for generating radiation within the multilayer structure and also a window having a first and a second main surface. The multi-layer structure adjoins the first main surface of the window. At least one recess, such as a trench or a pit, is formed in the window from the second main surface for the purpose of increasing the radiation efficiency. The recess preferably has a trapezoidal cross section tapering toward the first main surface and can be produced for example by sawing into the window.

Abstract: A light-emitting diode (1) has a lens body (3) that is fabricated from an inorganic solid. Fastened on the lens body (3) are semiconductor chips (2) that emit light beams (18). Furthermore, the light-emitting diode (1) is provided with a housing (20) that can be screwed into a conventional lamp holder via a thread (21).

Abstract: A light-emitting chip (3) has a lens-type coupling-out window (4), whose base area (5) is provided with a mirror area (6). Arranged on a coupling-out area (7) of the coupling-out window (4) is a layer sequence (9), with a photon-emitting pn junction (10). The photons emitted by the pn junction are reflected at the mirror area (6) and can leave the coupling-out window (4) through the coupling-out area (7).

Abstract: Proposed for high-performance light-emitting diodes are semiconductor chips (1) whose longitudinal sides are substantially longer than their transverse sides. Light extraction can be substantially improved in this manner.

Abstract: An optical semiconductor device with a multiple quantum well structure, is set out in which well layers and barrier layers, comprising various types of semiconductor layers, are alternately layered. The device well layers comprise a first composition based on a nitride semiconductor material with a first electron energy. The barrier layers comprise a second composition of a nitride semiconductor material with electron energy which is higher in comparison to the first electron energy. The well and barrier layers are in the direction of growth, by a radiation-active quatum well layer which with the essentially non-radiating well layers (6a) and the barrier layers (6b), arranged in front, form a supperlattice.

Abstract: A method for the sublimation growth of an SiC single crystal, involving heating up under growth pressure, is described. In the method for the sublimation growth of the SiC single crystal, a crucible holding a stock of solid SiC and an SiC seed crystal, onto which the SiC single crystal grows, is evacuated during a starting phase which precedes the actual growth phase and is then filled with an inert gas, until a growth pressure is reached in the crucible. Moreover, the crucible is initially heated to an intermediate temperature and then, in a heat-up phase, is heated to a growth temperature at a heat-up rate of at most 20° C./min. As a result, controlled seeding on the SiC seed crystal is achieved even during the heat-up phase.

Abstract: A device for the sublimation growth of an SiC single crystal, with foil-lined crucible. The device for producing an SiC single crystal includes a crucible with a crucible inner zone. Inside this zone, there is a storage area for storing a stock of solid SiC and a crystal area in which an SiC single crystal grows onto an SiC seed crystal. A heater device is arranged outside the crucible. On a side that faces the crucible inner zone, the crucible is lined with a foil of tantalum, tungsten, niobium, molybdenum, rhenium, iridium, ruthenium, hafnium or zirconium. As a result, the crucible is sealed and a reaction between the aggressive components of the SiC gas phase and the crucible wall is prevented.

Abstract: A seed crystal holder holds a SiC seed crystal while a SiC bulk single crystal is grown on the front surface of the seed crystal. The holder includes a back surface body with a bearing surface for bearing against a back surface of the SiC seed crystal. The holder includes a lateral mount for receiving the back surface body and the SiC seed crystal. The lateral mount has a projection located on an end facing the SiC seed crystal. The SiC seed crystal rests on the projection.

Abstract: An &agr;-SiC bulk single crystal is formed from an SiC gas phase by deposition of SiC on an SiC seed crystal. To enable an SiC bulk single crystal of the 15R type to be grown reproducibly and without restricting the seed crystal, the deposition takes place under a uniaxial tensile strength which includes a predetermined angle with the [0001] axis of the bulk single crystal, so that a rhombohedral crystal is formed.

Abstract: A method is described for growing at least one silicon carbide (SiC) single crystal by sublimation of a SiC source material. Silicon, carbon and a SiC seed crystal are introduced into a growing chamber. Then, the SiC source material is produced from the silicon and the carbon in a synthesis step that takes place before the actual growing. The growing of the SiC single crystal is then carried out immediately after the synthesis step. The carbon used is a C powder with a mean grain diameter of greater than 10 &mgr;m.

Abstract: A device for the sublimation growth of an SiC single crystal, with foil-lined crucible. The device for producing an SiC single crystal includes a crucible with a crucible inner zone. Inside this zone, there is a storage area for storing a stock of solid SiC and a crystal area in which an SiC single crystal grows onto an SiC seed crystal. A heater device is arranged outside the crucible. On a side that faces the crucible inner zone, the crucible is lined with a foil of tantalum, tungsten, niobium, molybdenum, rhenium, iridium, ruthenium, hafnium or zirconium. As a result, the crucible is sealed and a reaction between the aggressive components of the SiC gas phase and the crucible wall is prevented.

Abstract: A seed crystal holder holds a SiC seed crystal while a SiC bulk single crystal is grown on the front surface of the seed crystal. The holder includes a back surface body with a bearing surface for bearing against a back surface of the SiC seed crystal. The holder includes a lateral mount for receiving the back surface body and the SiC seed crystal. The lateral mount has a projection located on an end facing the SiC seed crystal. The SiC seed crystal rests on the projection.

Abstract: A method for the sublimation growth of an SiC single crystal, involving heating up under growth pressure, is described. In the method for the sublimation growth of the SiC single crystal, a crucible holding a stock of solid SiC and an SiC seed crystal, onto which the SiC single crystal grows, is evacuated during a starting phase which precedes the actual growth phase and is then filled with an inert gas, until a growth pressure is reached in the crucible. Moreover, the crucible is initially heated to an intermediate temperature and then, in a heat-up phase, is heated to a growth temperature at a heat-up rate of at most 20° C./min. As a result, controlled seeding on the SiC seed crystal is achieved even during the heat-up phase.