Abstract: A method and apparatus is described for producing Ge or a Ge.sub.1-x Si.sub.x heteroepitaxy film on Si by depositing films of Ge or Ge.sub.1-x Si.sub.x on Si and subjecting the body so formed to a controlled temperature environment, wherein the body is rapidly (within a time period t.sub.o of more than about 100 microseconds) brought to a predetermined temperature within the alloy range of the deposited film but less than the melting point of Si. The body is then held at such temperature for a relatively short time not to exceed about 3 minutes, including the time period t.sub.o.

Abstract: Transparent heat-mirrors are disclosed which are comprised of composite films. These films include a discrete and continuous layer of metallic silver sandwiched between a transparent, outer, protective, anti-reflection layer and a transparent, phase-matching layer. This combination of layers is chosen to provide high solar transmission with minimum loss of thermal radiation. Transparent heat-mirrors are useful in the collection and trapping of solar energy, and in other applications where it is desired or necessary to have high infrared reflectivity with high solar transmission.

Abstract: A selective-black absorber capable of operation at elevated temperatures and high efficiency as a solar energy absorber is described. A cermet of MgO/Au, MgO/Pt, and Cr.sub.2 O.sub.3 /Cr having high solar energy absorptance and low infrared energy emissivity is coated on a substrate having high infrared reflectivity such as Mo coated on stainless steel; Ni coated on Cu, or steel; aluminum, or steel. Typically an absorption coefficient of about 0.93 with an emissivity of about 0.09 is obtained and operation at a temperature of 300.degree.-400.degree. C. is possible depending on the cermet and substrate materials.

Abstract: An improved method for crystallizing amorphous material with a moving beam of energy is disclosed. In this method, the energy beam is scanned in a manner to provide controlled, continuous motion of the crystallization front.

Abstract: Transparent heat-mirrors are disclosed which are formed from tin-doped indium oxide films or antimony-doped tin oxide films deposited onto polymeric substrates. Low temperature deposition processes, such as ion-beam sputtering, are employed to preserve the polymeric substrates, and films having high transparency to visible radiation and high reflectivity to infrared radiation are deposited on the polymeric substrates by carefully controlling the partial pressure of oxygen during deposition.

Abstract: A method of applying an electrical contact and an anodic reflection coating to an n.sup.+ layer of a direct gap semiconductor device, comprising applying an anodizable metal contact to the n.sup.+ layer and thereafter anodizing the n.sup.+ layer whereby its thickness is reduced and an antireflection layer is formed thereover.

Abstract: Improvements in shallow-homojunction solar cells based upon a plurality of layers of a direct gap semiconductor material such as GaAs, as well as their fabrication, are disclosed. The shallow-homojunction solar cells have a n.sup.+ /p/p.sup.+ structure in which the n.sup.+ top layer is limited to a thickness which permits significant carrier generation to occur in a lower semiconductor layer. An anodic antireflection coating is applied over the n.sup.+ top layer, and a particularly preferred method for applying the antireflection coating is by anodization. These solar cells can be grown on relatively inexpensive substrates, if desired, such as silicon or germanium.

Abstract: A method of passivating imperfections, such as grain boundaries and/or dislocations, in semiconductor materials is disclosed which comprises selectively passing electrical current along the imperfections by employing the semiconductor material as an electrode in an electrolytic cell.

Abstract: Thick, finely-grained films of cermets are fabricated using conventional techniques of sputtering the ceramic and the metal onto a substrate. The cermet is then subjected to differential sputtering in which the metal is sputtered away faster than the ceramic to leave a ceramic-rich surface layer having excellent secondary-electron-emission properties for low-energy incident electrons. Typical of such cermets are MgO/Au, MgO/Pt and MgO/Ag. The presence of metallic particles in the bulk of the films and the small size of the ceramic particles greatly reduce surface charging while allowing the emitter film to be made thick enough to have a long operating life under adverse device conditions.

Abstract: A method is disclosed for improving the crystallinity of semiconductor films by scanning the surface of such films with a shaped, focused laser beam. The laser is matched to the film so that the beam delivers sufficient energy thereto to heat the film above a temperature at which crystallization occurs along the scan track.

Abstract: Thick, finely-grained films of cermets are fabricated using conventional techniques of sputtering the ceramic and the metal onto a substrate. The cermet is then subjected to differential sputtering in which the metal is sputtered away faster than the ceramic to leave a ceramic-rich surface layer having excellent secondary-electron-emission properties for low-energy incident electrons. Typical of such cermets are MgO/Au, MgO/Pt and MgO/Ag. The presence of metallic particles in the bulk of the films and the small size of the ceramic particles greatly reduce surface charging while allowing the emitter film to be made thick enough to have a long operating life under adverse device conditions.