The present disclosure relates to a fluorescent powder and a light-emitting device including the same. The fluorescent powder includes an inorganic compound. The inorganic compound contains components including an element M, an element A, an element D, an element E, and an element R. The element M is selected from Eu, Ce, Mn, Tb, Dy, and Tm, the element A is selected from Mg, Ca, Sr, and Ba, the element D is selected from B, Al, Ga, In, La, Gd, Sc, Lu, and Y, the element E is selected from Si, Ge, Zr, and Hf, and the element R is at least two elements selected from N, O, F, and Cl. In a powder X-Ray Diffraction (XRD) spectrum with CoK radiation, the inorganic compound at least has diffraction peaks within ranges of an Bragg angle (2) from 27.3 to 28.3, 29.7 to 30.7, 41.9 to 42.9, and 43.5 to 44.5.

A glass having from greater than or equal to about 0.1 mol. % to less than or equal to about 20 mol. % Ho.sub.2O.sub.3, and one or more chromophores selected from V, Cr, Mn, Fe, Co, Ni, Se, Pr, Nd, Er, Yb, and combinations thereof. The amount of Ho.sub.2O.sub.3 (mol. %) is greater than or equal to 0.7(CeO.sub.2 (mol. %)+Pr.sub.2O.sub.3 (mol. %)+Er.sub.2O.sub.3 (mol. %)). The glass can include one or more fluorescent ions selected from Cu, Sn, Ce, Eu, Tb, Tm, and combinations thereof in addition to, or in place of the chromophores. The glass can also include multiple fluorescent ions.

Disclosed are smoothing phosphors for AC LED lighting that are capable of prolonging the light emission time of an AC LED (or array of AC LEDs) during a cycle response to a phase change of the alternating current to substantially reduce flicker. The smoothing phosphor of the present teachings comprises a matrix represented by the formula: M.sub.(l-k-r-v)X.sub.(m-p)Al.sub.2(n-0.5x-0.5y)O.sub.3(n-0.5x-0.5y): Mn.sub.(x+p)O.sub.(x+p), Si.sub.yO.sub.2y, Eu.sub.k, R.sub.r, Li.sub.v wherein M is at least one of La.sub.2O.sub.3, Ce.sub.2O.sub.3, Gd.sub.2O.sub.3, Lu.sub.2O.sub.3, Ba.sub.2OF.sub.2, Sr.sub.2OF.sub.2, Ca.sub.2OF.sub.2, Ba.sub.2OCl.sub.2, Sr.sub.2OCl.sub.2, Ca.sub.2OCl.sub.2, BaO, SrO, CaO, or ZnO; provided that when M comprises BaO, SrO, CaO, or ZnO, M does not comprise La.sub.2O.sub.3, Ce.sub.2O.sub.3, Gd.sub.2O.sub.3, Lu.sub.2O.sub.3, Ba.sub.2OF.sub.2, Sr.sub.2OF.sub.2, Ca.sub.2OF.sub.2, Ba.sub.2OCl.sub.2, Sr.sub.2OCl.sub.2, or Ca.sub.2OCl.sub.2; X is at least one of MgO or ZnO; R is at least one of Sm, Pr, Tb, Dy, Er, or Ho; m=0 to 2; n=4 to 11; x=0.005 to 1; y=0.005 to 1; p=0 to 1; k=0 to 0.2; r=0 to 0.2; and v=0 to 0.2.

Disclosed are smoothing phosphors for AC LED lighting that are capable of prolonging the light emission time of an AC LED (or array of AC LEDs) during a cycle response to a, phase change of the alternating current to substantially reduce flicker. The smoothing phoshor of the present teachings comprises a matrix represented by the formula: (1krv)M.Math.(mp)X.Math.(n0.5x0.5y)Al.sub.2O.sub.3:(x+p)MnO, ySiO.sub.2, kEu, rR, vLi, wherein M is at least one of La.sub.2O.sub.3, Ce.sub.2O.sub.3, Gd.sub.2O.sub.3, Lu.sub.2O.sub.3, Ba.sub.2OF.sub.2, Sr.sub.2OF.sub.2, Ca.sub.2OF.sub.2, Ba.sub.2OCl.sub.2, Sr.sub.2OCl.sub.2, Ca.sub.2OCl, BaO, SrO, CaO, or ZnO; provided that when M comprises BaO, SrO, CaO, or ZnO, M does not comprise La.sub.2O.sub.3, Ce.sub.2O.sub.3, Gd.sub.2O.sub.3, Lu.sub.2O.sub.3, Ba.sub.2OF.sub.2, Sr.sub.2OF.sub.2, Ca.sub.2OF.sub.2, Ba.sub.2OCl.sub.2, Sr.sub.2OCl.sub.2, or Ca.sub.2OCl.sub.2; X is at least one of MgO or ZnO; R is at least one of Sm, Pr, Tb, Dy, Er, or Ho; m=0 to 2; n=4 to 11; x=0.005 to 1; y=0.005 to 1; p=0 to 1; k=0 to 0.2; r=0 to 0.2; and v=0 to 0.2.

The invention relates to faceted gemstones based on a luminescent glass composition that contains particular oxides of rare earth metals and thus enables the faceted gemstones to be identified, and to a process for identifying the gemstones.

The invention relates to a method for the preparation of a lithium silicate glass or a lithium silicate glass ceramic which comprise cerium ions and are suitable in particular for the preparation of dental restorations, the fluorescence properties of which largely correspond to those of natural teeth.

The invention also relates to a lithium silicate glass and a lithium silicate glass ceramic which can be obtained using the method according to the invention, the use thereof as dental material and in particular for the preparation of dental restorations, as well as a glass-forming composition which is suitable for use in the method according to the invention.

A phosphor converted white light emitting device comprises a solid-state light emitter (LED) operable to generate blue light with a dominant wavelength in range 440 nm to 470 nm; yellow to green-emitting phosphor operable to generate light with a peak emission wavelength in a range 500 nm to 550 nm; and a red-emitting manganese-activated fluoride phosphor such a manganese-activated potassium hexafluorosilicate phosphor (K.sub.2SiF.sub.6:Mn.sup.4+). The yellow to green and red-emitting phosphors are incorporated as a mixture and dispersed throughout a light transmissive material with an index or refraction of 1.40 to 1.43. In some embodiments the light transmissive comprises a dimethyl-based silicone. The device can further comprise an orange to red-emitting phosphor operable to generate light with a peak emission wavelength of 580 nm to 620 nm.