Abstract: A metal oxide semiconductor gas sensor and a method for production thereof. The sensor comprises a sensor-active metal oxide thin layer applied to a substrate, in contact with at least one electrode. The sensor-active metal oxide thin layer comprises a chromium/titanium oxide (CTO) layer with a thickness of about 10 nm to about 1 ?m. The chromium and titantium layers are applied over each other using thin layer technology and are subsequently tempered.

Abstract: A solder, in particular a thin-film solder, for joining microelectromechanical components, wherein the solder is a eutectic mixture of gold and bismuth. Components and devices joined by a solder of this type are also disclosed, in addition to processes for producing such components or devices.

Abstract: A microelectromechanical device and a method for producing it having at least one layer on a substrate, in particular a thermoelectric layer on a substrate, the thermal expansion coefficient of the at least one layer and the thermal expansion coefficient of the substrate differing greatly. The at least one layer is coupled to at least one stress reduction means for the targeted reduction of lateral mechanical stresses present in the layer. This achieves a stress-free layer or enables stress-free growth.

Abstract: A semiconductor component has at least one Peltier element and at least one thermogenerator element that are thermally coupled to one another via a coupling device. By virtue of the thermal coupling of the Peltier element and the thermogenerator element through the coupling device, it is possible to use the Peltier element to cool a microstructure, in particular an optoelectronic component (e.g. a laser diode). Efficient temperature regulation and efficient operation of an optoelectronic component are thus possible.

Abstract: A solder, in particular a thin-film solder, for joining microelectromechanical components, wherein the solder is a eutectic mixture of gold and bismuth. Components and devices joined by a solder of this type are also disclosed, in addition to processes for producing such components or devices.

Abstract: A microelectromechanical device and a method for producing it having at least one layer on a substrate, in particular a thermoelectric layer on a substrate, the thermal expansion coefficient of the at least one layer and the thermal expansion coefficient of the substrate differing greatly. The at least one layer is coupled to at least one stress reduction means for the targeted reduction of lateral mechanical stresses present in the layer. This achieves a stress-free layer or enables stress-free growth.

Abstract: A metal oxide semiconductor gas sensor and a method for production thereof. The sensor comprises a sensor-active metal oxide thin layer applied to a substrate, in contact with at least one electrode. The sensor-active metal oxide thin layer comprises a chromium/titanium oxide (CTO) layer with a thickness of about 10 nm to about 1 &mgr;m. The chromium and titantium layers are applied over each other using thin layer technology and are subsequently tempered.

Abstract: A method produces a thermoelectric layer structure on a substrate and the thermoelectric layer structure has at least one electrically anisotropically conductive V-VI layer, in particular a (Bi, Sb)2 (Te, Se)3 layer. The V-VI layer is formed by use of a seed layer or by a structure formed in the substrate, and disposed relative to the substrate such that an angle between the direction of the highest conductivity of the V-VI layer and the substrate is greater than 0°. The orientation can also be effected by an electric field. Components are formed of the thermoelectric layer structure in which the angle between the direction of the highest conductivity of the V-VI layer and the substrate is greater than 0°. As a result, the known anisotropy of the V-VI materials can advantageously be used for the construction of components.

Abstract: A method produces a thermoelectric layer structure on a substrate and the thermoelectric layer structure has at least one electrically anisotropically conductive V-VI layer, in particular a (Bi, Sb)2 (Te, Se)3 layer. The V-VI layer is formed by use of a seed layer or by a structure formed in the substrate, and disposed relative to the substrate such that an angle between the direction of the highest conductivity of the V-VI layer and the substrate is greater than 0°. The orientation can also be effected by an electric field. Components are formed of the thermoelectric layer structure in which the angle between the direction of the highest conductivity of the V-VI layer and the substrate is greater than 0°. As a result, the known anisotropy of the V-VI materials can advantageously be used for the construction of components.

Abstract: A semiconductor component has at least one Peltier element and at least one thermogenerator element that are thermally coupled to one another via a coupling device. By virtue of the thermal coupling of the Peltier element and the thermogenerator element through the coupling device, it is possible to use the Peltier element to cool a microstructure, in particular an optoelectronic component (e.g. a laser diode). Efficient temperature regulation and efficient operation of an optoelectronic component are thus possible.

Abstract: Silicic acid heteropolycondensates made from hydrolyzable silicic acid derivatives and substituted silanes, optionally with either or both of one or more functional silanes and non-volatile metal oxides or their precursors are made by a known technique, in which the reaction mixture is hydrolyzed and condensed by the action of water and a condensation catalyst, the latter being employed in an amount up to 3% by weight, based upon the weight of the reaction mixture. Improved heteropolycondensates usable as adsorbents and porous membranes can be made by using greater amounts of catalyst, ranging up to 75% by weight, based upon the weight of the reaction mixture. These improved products are very stable in use and are characterized by a pore structure which includes fine pores and coarse pores, whereby products in the form of membranes can have an asymmetrical structure, if desired.