Abstract: The present invention is directed to rare-earth doped solid state solutions of alkaline earth fluorides having novel luminescence properties, and to a process for preparing them. The invention is useful as identifying markers on articles. Other uses include phosphors for plasma displays, optical frequency multipliers, optical amplifiers and the like.

Abstract: A process for the production of a silicon solar cell comprising application and firing of an aluminum paste which comprises magnesium oxide and/or magnesium compounds capable of forming magnesium oxide on firing on the back-side of a silicon wafer provided with a silicon nitride antireflective coating on its front-side and being contaminated with silicon nitride on its back-side, and firing the aluminum paste after its application.

Abstract: Described herein are a silicon semiconductor device and a conductive silver paste for use in the front side of a solar cell device.

Abstract: Described herein are a silicon semiconductor device and a conductive silver paste for use in the front side of a solar cell device.

Abstract: Described herein are a silicon semiconductor device and a conductive lead-free silver paste for use in the front side of a solar cell device.

Abstract: The invention is directed to a composition having a carrier matrix, and a particulate luminescent composition dispersed therein, the particulate luminescent composition comprising a rare-earth-doped alkaline earth fluoride represented by the formula RExA1?xF2+x?2yOy wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002?x?0.20, and 0?y?x; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths. It is further directed to a process by contacting a surface with the composition and articles made therefrom.

Abstract: A method wherein an aqueous solution of a fluoride, an aqueous solution of a Group 2 or Group 3 metal salt, and an aqueous solution of a rare-earth metal dopant are combined in a plurality of continuous feed streams to form a series of precipitates of a rare-earth doped Group 2 or Group 3 metal fluoride, and wherein the member of the series differ by the concentration of the associated rare-earth dopant cation in the feed stream, and wherein the series so prepared defines the threshold concentration range above which operation of the process results in a minimization of the particle size variability caused by small perturbations in the concentration of the rare-earth dopant.

Abstract: A method wherein an aqueous solution of a fluoride, an aqueous solution of a Group 2 or Group 3 metal salt, and an aqueous solution of a rare-earth metal dopant are combined to form a precipitate of a rare-earth doped Group 2 or Group 3 metal fluoride, and wherein increasing the concentration of the rare-earth dopant cation increases the resulting particle size, and wherein decreasing the concentration of the rare-earth dopant cation decreases the particle size.

Abstract: The invention is directed a composition represented by the chemical formula EuxA1?xF2+x?2yOy wherein A is alkaline earth, 0.002?x?0.20, and 0?y?x; the composition exhibiting a luminescence spectrum characterized by peaks at 592±2 nm and 627±2 nm, wherein the ratio of the peak intensity at 592±2 nm to that at 627±2 nm is at least 5% larger than the corresponding peak intensity ratio at the same wavelengths of a first corresponding reference composition with the same value of x that has not been exposed to a temperature above 100° C., and wherein said ratio of the peak intensity at 592±2 nm to that at 627±2 nm is at least 5% smaller than the corresponding peak intensity ratio at the same wavelengths of a second corresponding reference composition with the same value of x that has been subject to heating to 900° C. for 6 hours.

Abstract: The invention is directed to a method by exposing at least a portion of a luminescent coating disposed on a surface of an article to ultraviolet light at one or more preselected wavelengths causing said luminescent coating to exhibit a luminescence spectrum, the luminescence spectrum exhibiting a plurality of intensity peaks that have been priorly determined to create a standard; determining the intensity of at least two peaks in the luminescence spectrum of the coating; determining a peak intensity ratio of the at least two peaks; comparing the peak intensity ratio determined with the standard; and, classifying the article according to whether or not the peak intensity ratio does or does not match the standard; wherein the luminescent coating comprises a particulate luminescent composition comprising a rare earth doped fluoride represented by the formula RExA1?xF2+x?2yOy wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002?x?0.20, and 0?y?x.

Abstract: Described herein are a silicon semiconductor device and a conductive silver paste for use in the front side of a solar cell device.

Abstract: Described herein are a silicon semiconductor device and a conductive lead-free silver paste for use in the front side of a solar cell device.

Abstract: The invention is directed to a method by exposing at least a portion of a luminescent coating disposed on a surface of an article to ultraviolet light at one or more preselected wavelengths causing said luminescent coating to exhibit a luminescence spectrum, the luminescence spectrum exhibiting a plurality of intensity peaks that have been predetermined to create a standard; determining the intensity of at least two peaks in the luminescence spectrum of the coating; determining a peak intensity ratio of the at least two peaks; comparing the peak intensity ratio determined with the standard; and, classifying the article according to whether or not the peak intensity ratio does or does not match the standard; wherein the luminescent coating is a particulate luminescent composition comprising a rare earth doped fluoride represented by the chemical formula REx(CaaSrbBac)1?xF2+x?2yOy wherein RE represents a three-valent rare-earth element, 0.005?x?0.20, and 0?y?0.

Abstract: The present invention is directed to rare-earth doped solid state solutions of alkaline earth fluorides having novel luminescence properties, and to a process for preparing them. The invention is useful as identifying markers on articles. Other uses include phosphors for plasma displays, optical frequency multipliers, optical amplifiers and the like.

Abstract: The invention is directed to a method by exposing at least a portion of a luminescent coating disposed on a surface of an article to ultraviolet light at one or more preselected wavelengths causing said luminescent coating to exhibit a luminescence spectrum, the luminescence spectrum exhibiting a plurality of intensity peaks that have been predetermined to create a standard; determining the intensity of at least two peaks in the luminescence spectrum of the coating; determining a peak intensity ratio of the at least two peaks; comparing the peak intensity ratio determined with the standard; and, classifying the article according to whether or not the peak intensity ratio does or does not match the standard; wherein the luminescent coating is a particulate luminescent composition comprising a rare earth doped fluoride represented by the chemical formula REx(CaaSrbBac)1?xF2+x?2yOy wherein RE represents a three-valent rare-earth element, 0.005?x?0.20, and 0?y?0.

Abstract: The invention is directed to a composition having a carrier matrix, and a particulate luminescent composition dispersed therein, the particulate luminescent composition comprising a rare-earth-doped solid-state solution of alkaline earth fluorides represented by the chemical formula REx(CaaSrbBac)1?xF2+x?2yOy wherein RE represents a three-valent rare-earth element, 0.005?x?0.20, and 0?y?0.2, a+b+c=1, with the proviso at least two of a, b, and c are not equal to zero; the particulate luminescent composition exhibiting a luminescence spectrum having a plurality of intensity peaks at characteristic wavelengths. It is further directed to a process by contacting a surface with the composition and articles made therefrom.

Abstract: The invention is directed a composition represented by the chemical formula EuxA1?xF2+x?2yOy wherein A is alkaline earth, 0.002?x?0.20, and 0?y?x; the composition exhibiting a luminescence spectrum characterized by peaks at 592±2 nm and 627±2 nm, wherein the ratio of the peak intensity at 592±2 nm to that at 627±2 nm is at least 5% larger than the corresponding peak intensity ratio at the same wavelengths of a first corresponding reference composition with the same value of x that has not been exposed to a temperature above 100° C., and wherein said ratio of the peak intensity at 592±2 nm to that at 627±2 nm is at least 5% smaller than the corresponding peak intensity ratio at the same wavelengths of a second corresponding reference composition with the same value of x that has been subject to heating to 900° C. for 6 hours.

Abstract: The invention is directed to a method by exposing at least a portion of a luminescent coating disposed on a surface of an article to ultraviolet light at one or more preselected wavelengths causing said luminescent coating to exhibit a luminescence spectrum, the luminescence spectrum exhibiting a plurality of intensity peaks that have been priorly determined to create a standard; determining the intensity of at least two peaks in the luminescence spectrum of the coating; determining a peak intensity ratio of the at least two peaks; comparing the peak intensity ratio determined with the standard; and, classifying the article according to whether or not the peak intensity ratio does or does not match the standard; wherein the luminescent coating comprises a particulate luminescent composition comprising a rare earth doped fluoride represented by the formula RExA1-xF2+x-2yOy wherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002?x?0.20, and 0?y?x.

Abstract: Hydrofluoric acid-resistant ceramic mortar compositions containing a hydrofluoric acid-resistant grog having a particle size distribution imparting a high particle packing fraction to the mortar composition and a binding phase containing a metal salt having a particle size distribution imparting plasticity to the mortar composition selected from hydrofluoric acid-insoluble fluoride salts, metal salts capable of forming hydrofluoric acid-insoluble fluoride salts upon reaction with a fluorinating reagent and mixtures thereof. Methods for forming hydrofluoric acid-resistant ceramic mortar compositions from non-fluoride metal salts are also disclosed as well as methods for bonding refractory bricks into a brickwork unit with the ceramic mortars of the invention. Brickwork units prepared using the ceramic mortar compositions of the invention by the methods of the invention are also described.

Abstract: This invention provides new refractory binder compositions comprising silica and titania which can be used to make ceramic bodies, particularly bricks. The refractory binder compositions comprise about 70 to about 92 wt. % silica (SiO.sub.2) and about 8 to about 30% titania (TiO.sub.2). The refractory binder compositions may further comprise alumina and a metal oxide selected from the group consisting of calcium oxide, strontium oxide, and sodium oxide, and mixtures thereof. The refractory ceramic bodies can be used in hot corrosive/erosive environments such as in fluid bed chlorinators in the manufacture of titanium dioxide.