Abstract: The space glass has a composition, in wt. % based on oxide content, of: SiO2, 5-65; B2O3, 0-40; Al2O3, 0-12; PbO, 25-50; Na2O 0-8; K2O, 0-20; ? alkali metal oxides, at least 0.25; and at least 0.1 wt. % of a total amount of three or more doping agents selected from CeO2, MoO3, Bi2O3, WO3, Ag2O, SnO2, Sb2O3 and As2O3. In addition, it contains one or more of the following doping agents in the following amounts: at most 1 wt. %, CeO2; at most 0.02 wt. %, As2O3; at most 0.3 wt. %, Sb2O3; and at most 0.5 wt. %, SnO2. Light-weight optical systems for space are made from it, because of its high radiation resistance. A preferred process for making space glass includes melting the oxide starting ingredients at 1050° C. to 1200° C. to form a melt and refining the melt at 1230° C. to 1350° C.

Abstract: The space glasses have a composition, in wt. % based on oxide content, including SiO2, 12-45; B2O3, 0-4; Al2O3, 0-4; TiO2, 0-5; PbO, 50-82; Na2O, 0-4; K2O, 0-8; and at least 0.1 wt. % of a total amount of at least three doping agents selected from CeO2, MoO3, Bi2O3, WO3, Ag2O, SnO2, Sb2O3 and As2O3. Light-weight and space-saving optical systems for outer space applications can be made with these space glasses, which have high UV- and VIS-transmittance and high transmittance stability, because of their high radiation resistance based on their dopant content. A preferred process for making the space glass includes melting the above-stated oxide ingredients in a quartz crucible at 1050° C. to 1200° C. to form a melt and refining the melt at 1230° C. to 1350° C.

Abstract: Utilization of a glass for photovoltaic applications, whereby the glass has a water content of <25 mMol/liter, for example >1 mMol/liter. The used glasses may have a transformation temperature Tg in an approximate range of >580° C., a processing temperature (“VA”) in the range of approximately 1150° C. and a thermal heat expansion coefficient in the range of approximately 7 to 11×10?6/K. These glasses may be used in a high temperature process without releasing semiconductor toxins such as iron, arsenic and boron, and are suitable for Cd—Te or for CIS or respectively CIGS photovoltaic applications since the processing ability/deposition compared to traditionally used soda lime glasses can occur at higher temperatures due to higher temperature stability.

Abstract: The optical glasses have increased refractive indices and are useful for making space-saving and light-weight imaging optics with lenses of different glass types for use in different objects travelling in space. The optical glasses are suitable for production of optics having low total weight, which is decisive for space applications. These space glasses have high UV- and VIS-transmittance in a range of between 300 and 800 nm and high stability of transmittance over a period of years, because their aging has been greatly limited.

Abstract: The optical glasses have increased refractive indices and are useful for making space-saving and light-weight imaging optics with lenses of different glass types for use in different objects travelling in space. The optical glasses are suitable for production of optics having low total weight, which is decisive for space applications. These space glasses have high UV- and VIS-transmittance in a range of between 300 and 800 nm and high stability of transmittance over a period of years, because their aging has been greatly limited.

Abstract: The thin-film solar cell includes at least one Na2O-containing multicomponent substrate glass. The substrate glass contains less than 1% by weight of B2O3, less than 1% by weight of BaO and a total of less than 3% by weight of CaO+SrO+ZnO, the molar ratio of the substrate glass components, (Na2O+K2O)/(MgO+CaO+SrO+BaO), is greater than 0.95, the molar ratio of the substrate glass components SiO2/Al2O3 is less than 7 and the substrate glass has a glass transition temperature Tg of greater than 550° C., in particular greater than 600° C. The thin-film solar cells made with this substrate glass have improved efficiencies in comparison to thin-film solar cells of the prior art.

Abstract: The electronic semiconductor component has a crystalline wafer substrate with an active surface and a semiconductor layer coating the active surface. So that the semiconductor layer has a few surface defects the crystalline wafer substrate is a sapphire or silicon carbide single crystal and the active surface has a pit density of less than 500 pit/cm2, preferably less than 100 pit/cm2. The polishing method for obtaining the active surface with these pit densities includes polishing with a polishing agent, such as a silicon suspension, and a polishing tool, which is pressed on the active surface with a pressure of preferably from 0.05 to 0.2 kg/cm2 and moved over the active surface with polishing motions distributed statistically and uniformly over a 360° angle during polishing.

Abstract: A method is described for making low-stress single crystals with a hexagonal crystal structure, which has a crystallographic c-axis perpendicular to a [0001] surface. A single crystal maintained at a temperature under the melting point of the crystal raw material is dipped in a melt of the crystal raw material, whereby a solid-liquid phase boundary is formed. The crystal is subsequently drawn with an upwardly directed drawing motion e.g. by the Czochralski method. The method is characterized by drawing the crystal along the c-axis so that a temperature gradient of at least 30 K/cm is present in the crystal within a centimeter of the solid-liquid phase boundary and by subsequently performing a tempering treatment on the resulting single crystal. The method is especially suitable for corundum crystals, such as sapphire, which are used as substrates for semiconductor components, such as LEDs.

Abstract: The method of making an especially low-stress wafer substrate with an active surface to be coated with few surface defects that produce coating defects includes polishing the active surface with the help of a polishing tool in order to smooth it and changing a polishing direction of the polishing tool performing the polishing over the active surface so that each site or location on the surface is polished with polishing motions distributed statistically and uniformly over a 360° angle.

Abstract: In the method and apparatus for measuring the position of the phase interface during growth of a crystal from a melt in a crystal growth container according to the VGF method an incident optical signal is propagated to the phase interface between the melt and the crystal through a window (16) in the container (10) and a received optical signal reflected from the phase interface (14) is measured to determine the position of the phase interface. The position of the phase interface is established from the reflected signal by triangulation with a confocal optic system, by interferometric balancing or by transit time of the optical signal. The window (16) is preferably mounted in a preferably tilted orientation at the end of a tube (15), which is immersed in the melt (12).

Abstract: A cadmium-free optical steep edge filter comprising I-III-VI compound semiconductor systems of stoichiometric or non-stoichiometric composition, where the I-III-VI compound semiconductors are systems with one or more of the following elements: for the univalent (I) elements: Cu, Ag for the tervalent (III) elements: Al, In, Ga for the hexavalent (VI) elements: S, Se, Te.

Abstract: A method is described for making low-stress single crystals with a hexagonal crystal structure, which has a crystallographic c-axis perpendicular to a [0001] surface. A single crystal maintained at a temperature under the melting point of the crystal raw material is dipped in a melt of the crystal raw material, whereby a solid-liquid phase boundary is formed. The crystal is subsequently drawn with an upwardly directed drawing motion e.g. by the Czochralski method. The method is characterized by drawing the crystal along the c-axis so that a temperature gradient of at least 30 K/cm is present in the crystal within a centimeter of the solid-liquid phase boundary and by subsequently performing a tempering treatment on the resulting single crystal. The method is especially suitable for corundum crystals, such as sapphire, which are used as substrates for semiconductor components, such as LEDs.

Abstract: A method of making a fracture-resistant large-size calcium fluoride single crystal is described, which is suitable for an optical component for radiation in the far UV range. The calcium fluoride raw material for the single crystal is first melted and subsequently solidified by cooling the melt to form a single crystal. However the calcium fluoride raw material is doped with from 1 to 250, preferably 1 to 100, ppm of strontium, preferably added as strontium fluoride, and contains from 1 to 10 ppm of sodium as well as up to 100 ppm of other impurities.

Abstract: The method for determining radiation stability of a crystal to radiation of a working wavelength to be employed in a subsequent application includes taking a first absorption spectrum (A) of a cleaved piece of the crystal with a given thickness (D) over a predetermined wavelength range from a first wavelength (&lgr;1) to a second wavelength (&lgr;2) by means of a spectrophotometer. Then the cleaved piece of the crystal is irradiated with an energetic radiation source so as to form all theoretically possible color centers (saturation). After the irradiating a second absorption spectrum (B) of the cleaved piece of crystal is taken over the same predetermined wavelength range. Then a surface integral of a difference spectrum of the first absorption spectrum and the second absorption spectrum over the predetermined wavelength range is formed and divided by the thickness (D) to obtain a scaled surface integral value.

Abstract: The invention relates to cadmium-free optical steep edge filters comprising I-III-VI compound semiconductor systems of stoichiometric or non-stoichiometric composition, where the I-III-IV compound semiconductors are systems with one or more of the following elements:

Abstract: A method of making a fracture-resistant large-size calcium fluoride single crystal is described, which is suitable for an optical component for radiation in the far UV range. The calcium fluoride raw material for the single crystal is first melted and subsequently solidified by cooling the melt to form a single crystal. However the calcium fluoride raw material is doped with from 1 to 250, preferably 1 to 100, ppm of strontium, preferably added as strontium fluoride, and contains from 1 to 10 ppm of sodium as well as up to 100 ppm of other impurities.

Abstract: A method for producing crystals and/or crystal materials is described whereby the undesirable impurities are removed from the crystal and/or the material with the aid of a purification agent or getter. Elemental fluorine and/or a reactive fluorine-containing substance is used as the purification agent or getter. Preferred getters are XeF2 and/or carbon fluoride. Crystals obtained in this manner are suitable for use as optical components.

Abstract: In the method and apparatus for measuring the position of the phase interface during growth of a crystal from a melt in a crystal growth container according to the VGF method an incident optical signal is propagated to the phase interface between the melt and the crystal through a window (16) in the container (10) and a received optical signal reflected from the phase interface (14) is measured to determine the position of the phase interface. The position of the phase interface is established from the reflected signal by triangulation with a confocal optic system, by interferometric balancing or by transit time of the optical signal. The window (16) is preferably mounted in a preferably tilted orientation at the end of a tube (15), which is immersed in the melt (12).

Abstract: The method for determining radiation stability of a crystal to radiation of a working wavelength to be employed in a subsequent application includes taking a first absorption spectrum (A) of a cleaved piece of the crystal with a given thickness (D) over a predetermined wavelength range from a first wavelength (&lgr;1) to a second wavelength (&lgr;2) by means of a spectrophotometer. Then the cleaved piece of the crystal is irradiated with an energetic radiation source so as to form all theoretically possible color centers (saturation). After the irradiating a second absorption spectrum (B) of the cleaved piece of crystal is taken over the same predetermined wavelength range. Then a surface integral of a difference spectrum of the first absorption spectrum and the second absorption spectrum over the predetermined wavelength range is formed and divided by the thickness (D) to obtain a scaled surface integral value.

Abstract: The method for making a uniform, large-size single crystal of calcium fluoride includes placing a single precursor crystal of calcium fluoride in a tempering vessel provided with a cover; introducing calcium fluoride powder into the tempering vessel and subsequently heating the single precursor crystal, preferably in intimate contact with the calcium fluoride powder, in the tempering vessel together with the calcium fluoride powder for two or more hours at temperatures above 1150° C. to temper the precursor crystal and thus form the uniform, large-scale single crystal of calcium fluoride. The uniform large-sized single crystals of calcium fluoride can be used to make improved lens, prism, light-conducting rod, optical window or other optical component for DUV photolithography, steppers, excimer lasers, wafers, computer chips and electronic devices containing the wafers and chips.