Abstract: Phosphors comprises oxides of at least an alkaline-earth metal selected from the group consisting of strontium, barium, calcium, and combinations thereof and at least a Group-IIIB metal selected from the group consisting of aluminum, gallium, indium, and combinations thereof activated with rare-earth metal ions comprising at least europium. The phosphors are characterized in that the ratio of positive ions and negative ions is off-stoichiometric. The phosphors are excitable efficiently in the near UV-to-blue light range. Blends containing at least one of these phosphors in conjunction with at least a light-emitting diode can provide light sources having a high luminosity and a high color-rendering index.

Abstract: Europium-activated phosphors comprise oxides of at least a rare-earth metal selected from the group consisting of gadolinium, yttrium, lanthanum, and combinations thereof and at least a Group-IIIB metal selected from the group consisting of aluminum, gallium, indium, and combinations thereof. A method for making such phosphors comprises adding at least a halide of at least one of the selected Group-IIIB metals in a starting mixture. The method further comprises firing the starting mixture in an oxygen-containing atmosphere. The phosphors produced by such a method exhibit improved absorption in the UV wavelength range and improved quantum efficiency.

Abstract: Scintillator compositions having a garnet crystal structure useful for the detection of high-energy radiation, such as X, &bgr;, and &ggr; radiation, contain (1) at least one of terbium and lutetium; (2) at least one rare earth metal; and (3) at least one of Al, Ga, and In. Terbium or lutetium may be partially substituted with Y, La, Gd, and Yb. In particular, the scintillator composition contains both terbium and lutetium. The scintillators are characterized by high light output, reduced afterglow, short decay time, and high X-ray stopping power.

Abstract: Strontium and strontium calcium aluminates and lanthanum and lanthanum magnesium borates activated with Pr3+ and Mn2+ exhibit characteristics of quantum-splitting phosphors. Improved quantum efficiency may be obtained by further doping with Gd3+. Refined rules for designing quantum-splitting phosphors include the requirement of incorporation of Gd3+ and Mn2+ in the host lattice for facilitation of energy migration.

Abstract: Halophosphate luminescent materials co-activated with europium and manganese ions and having the general formula of (Ca,Sr,Ba,Mg)5(PO4)3:Eu2+,Mn2+ are disclosed. The inclusion of manganese shifts the peak emission to longer wavelengths and, thus, is beneficial in generating a bright yellow-to-orange light. White-light sources are produced by disposing a halophosphate luminescent material, optionally with a blue light-emitting phosphor, in the vicinity of a near UV/blue LED. Blue light-emitting phosphors that may be used in embodiments of the present inventions are Sr4Al14O25:Eu2+, Sr6P6BO20:Eu2+, BaAl8O13:Eu2+, (Sr,Mg,Ca,Ba)5(PO4)3Cl:Eu2+, and Sr2Si3O6.2SrCl2:Eu2+.

Abstract: Strontium, calcium, strontium calcium, strontium calcium magnesium, calcium magnesium aluminates, and strontium borates activated with Pr3+ exhibit characteristics of quantum-splitting phosphors under VUV excitation. A large emission peak at about 405 nm under VUV excitation is used conveniently to identify quantum-splitting phosphors. Improvements may be achieved with addition of fluorides or boric acid as a flux during the preparation of the phosphors. It is also possible to predict improvement in quantum efficiency by observing the ratio of emission intensities at about 480 nm and about 610 nm.

Abstract: Halophosphate luminescent materials co-activated with europium and manganese ions and having the general formula of (Ca,Sr,Ba,Mg)5(PO4)3:Eu2+, Mn2+ are disclosed. The inclusion of manganese shifts the peak emission to longer wavelengths and, thus, is beneficial in generating a bright yellow-to-orange light. White-light sources are produced by disposing a halophosphate luminescent material, optionally with a blue light-emitting phosphor, in the vicinity of a near UV/blue LED. Blue light-emitting phosphors that may be used in embodiments of the present inventions are Sr4Al14O25:Eu2+, Sr6P6BO20:Eu2+, BaAl8O13:Eu2+, (Sr,Mg,Ca,Ba)5(PO4)3Cl:Eu2+, and Sr2Si3O6.2SrCl2:Eu2+.

Abstract: A rare earth-activated terbium-containing garnet phosphor is capable of absorbing radiation in the range from near UV to blue and emitting a broad spectrum of visible light in the range from about 490 nm to about 770 nm. The emission of the phosphor under an excitation at 450 nm exhibits a peak in the range of maximum sensitivity of the human eye. A light source combining a UV/blue LED and this phosphor can provide a white light that is on or near the Planckian locus and may be useful for general illumination.

Abstract: A method for determining past-service conditions and/or remaining useful life of a component of a combustion engine and/or a thermal barrier coating (“TBC”) of the component comprises providing a photoluminescent (“PL”) material in the TBC, directing an exciting radiation at the TBC, measuring the intensity of a characteristic peak in the emission spectrum of the PL material, and correlating the intensity of the characteristic peak or another quantity derived therefrom to an amount of a new phase that has been formed as a result of the exposure of the component to extreme temperatures.

Abstract: Scintillator compositions having a garnet crystal structure useful for the detection of high-energy radiation, such as X, &bgr;, and &ggr; radiation, contain (1) at least one of terbium and lutetium; (2) at least one rare earth metal; and (3) at least one of Al, Ga, and In. Terbium or lutetium may be partially substituted with Y, La, Gd, and Yb. In particular, the scintillator composition contains both terbium and lutetium. The scintillators are characterized by high light output, reduced afterglow, short decay time, and high X-ray stopping power.

Abstract: A rare earth-activated terbium-containing garnet phosphor is capable of absorbing radiation in the range from near UV to blue and emitting a broad spectrum of visible light in the range from about 490 nm to about 770 nm. The emission of the phosphor under an excitation at 450 nm exhibits a peak in the range of maximum sensitivity of the human eye. A light source combining a UV/blue LED and this phosphor can provide a white light that is on or near the Planckian locus and may be useful for general illumination.

Abstract: Strontium, calcium, strontium calcium, strontium calcium magnesium, calcium magnesium aluminates, and strontium borates activated with Pr3+ exhibit characteristics of quantum-splitting phosphors under VUV excitation. A large emission peak at about 405 nm under VUV excitation is used conveniently to identify quantum-splitting phosphors. Improvements may be achieved with addition of fluorides or boric acid as a flux during the preparation of the phosphors. It is also possible to predict improvement in quantum efficiency by observing the ratio of emission intensities at about 480 nm and about 610 nm.

Abstract: Strontium and strontium calcium aluminates and lanthanum and lanthanum magnesium borates activated with Pr3+ and Mn2+ exhibit characteristics of quantum-splitting phosphors. Improved quantum efficiency may be obtained by further doping with Gd3+. Refined rules for designing quantum-splitting phosphors include the requirement of incorporation of Gd3+ and Mn2+ in the host lattice for facilitation of energy migration.

Abstract: Phosphor blends are disclosed that are capable of absorbing electromagnetic ation having wavelengths in the range from about 315 nm to about 480 nm. O25:Eu2+,(Sr,Ba,Ca)5(PO4)3(Cl,OH):Eu2+,(Ba,Ca,Sr)2MgAl16O27: Eu2+, and (Ba,Ca,Sr)2MgAl16O27:Eu2+,Mn2+. White light sources are obtained by lying a phosphor blend over at least one LED that is capable of emitting electromagnetic radiation in the above-noted wavelength range.