Abstract: The invention relates to a catalyst body with one or several layer elements with etched cavities, through which flowing media may flow, such as for example, pores or channels. The cavities are essentially arranged perpendicular to the layer elements and the production is by means of etching methods from semiconductor technology.

Abstract: A silicon-germanium thin-film solar cell having a quantum well structure as an active base layer within the space-charge region of the silicon p-n diode junction. The quantum well structure is composed of a sequence of silicon and germanium layers. In this manner, a highly absorbent base layer is produced in a silicon solar cell.

Abstract: A silicon-germanium thin-film solar cell having a quantum well structure as an active base layer within the space-charge region of the silicon p-n diode junction. The quantum well structure is composed of a sequence of silicon and germanium layers. In this manner, a highly absorbent base layer is produced in a silicon solar cell.

Abstract: A voltage-controlled, wavelenght-selective photodetector includes comprising a double diode having a counter-polarized Si-Schottky diode and a SiGe PIN diode. The short-wave portion (&lgr;<0.9 &mgr;m) of the light entering the detector through a window generates electron-hole pairs in the Si-Schottky diode, while the longer-wave portion (1 &mgr;m<&lgr;<2 &mgr;m) passes through the substrate and is absorbed in the epitaxially deposited SiGe superlattice or the quantum well diode. The photocurrents of both detectors flow in physically opposite directions and subtract from each other, resulting in a wavelength-dependent operational sign of the photocurrent. The level of the bias voltage applied determines whether the photocurrent of the Si-Schottky diode or the photocurrent of the Si/Ge PIN diode determines the spectrum.

Abstract: A photodetector which can be operated in two wavelength ranges and is comprised of two detectors (A, B) arranged one on top of the other. A Si Schottky diode forms detector A which absorbs light in a region .lambda.<0.9 .mu.m. Longer-waved light (1 .mu.m<.lambda.<2 .mu.m) is absorbed in detector B which is comprised of an Si/SiGe pn-diode. To increase the efficiency, detector B is made with an integrated resonator. A further increase of the efficiency of the photodetector is accomplished through the mounting of a Bragg reflector on the absorbing layer of detector B.

Abstract: A valence band quantum-well structure with a modulation doping for an optical-component implemented in Si technology. With this component, a high quantum efficiency and detection efficiency are accomplished. By way of spatial separation of the doped zone from the almost undoped SiGe quantum well, the Coulomb scattering and the recombination probability of the charge carriers drifting in the externally applied electrical field is greatly reduced at the doping material cores.