A device for converting solar radiation is described wherein the device comprises an inorganic luminescent material comprising a host material doped with Mn5+ ions for converting radiation of the UV and/or visible part of the electromagnetic spectrum into radiation of the near-infrared radiation part of the electromagnetic spectrum, preferably the infrared part between 1150 nm and 1250 nm, preferably around 1190 nm (the infrared emission peak of Mn.sup.5+); or, an amorphous host material doped with Sm.sup.2+ or Tm.sup.2+ ions, the amorphous host material including the elements Al, Si, O and N (SiAION) for converting radiation of the UV and/or visible part of the electromagnetic spectrum into radiation of a longer wavelength, preferably a longer wavelength between 650 n and 800 nm or a longer wavelength of around 1140 n; and, at least one photovoltaic device for converting at least part of the converted radiation into electrical power.

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

A nitride phosphor particle dispersion-type sialon ceramic of the present invention includes a matrix formed of a sialon-based compound; and at least one nitride phosphor which is dispersed in the matrix and contains a luminescence center element.

A lighting device is presented. The lighting device includes an LED light source; and a red/far-red emitting phosphor radiationally coupled to the LED light source, wherein the red/far-red emitting phosphor comprises a host material activated with an activator ion, and wherein the activator ion comprises at least one of Sm.sup.2+ and Mn.sup.2+. Numerous other aspects are provided.

An object of the present invention is to provide an infrared light-emitting phosphor which emits light in a wavelength range where the sensitivity of a detector is high by combination with a semiconductor light-emitting element that emits light in the visible light region, and to provide an infrared light-emitting device using the infrared light-emitting phosphor. The object can be achieved with a light-emitting device including a semiconductor light-emitting element that emits ultraviolet light or visible light and a phosphor that absorbs ultraviolet light or visible light emitted from the semiconductor light-emitting element and emits light in the infrared region, wherein an emission peak wavelength in the infrared region of the phosphor emitting in the infrared region is from 750 to 1,050 nm, and the half width of an emission peak waveform is more than 50 nm.

This technology is directed to the preparation of doped-bismuth-silicate seed crystals through controlled crystallization (e.g. dimensionality of growth and nucleation mechanism) and the method of forming high purity single seed (particle size ranges from micrometers to millimeters) for various uses. These seed crystals have a nominal stoichiometry of Bi.sub.2-xA.sub.xSiO.sub.5, Bi.sub.2-xA.sub.xSi.sub.3O.sub.9, Bi.sub.4-xA.sub.xSi.sub.3O.sub.9, and Bi.sub.12-xA.sub.xSiO.sub.20, where A is a rare earth dopant selected from La, Ce, Nd, Pr, and/or Sm.

A nitride phosphor particle dispersion-type sialon ceramic of the present invention includes a matrix formed of a sialon-based compound; and at least one nitride phosphor which is dispersed in the matrix and contains a luminescence center element.

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.

A phosphor, combined with LED having not exceeding 470 nm, of high emission intensity and with chemical and thermal stability is provided. The phosphor according to the present invention comprises an inorganic compound in which element A (A is one or two or more kinds of elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) is solid solved in an inorganic crystal including at least metal element M and non-metal element X and represented by M.sub.nX.sub.n+1 (3n5), an inorganic crystal having the same crystal structure, or an inorganic crystal including a solid solution thereof. Here, M comprises at least Al and Si, and if necessary element L (L is a metal element other than Al and Si) and X comprises N, O if necessary, and element Z if necessary (Z is a non-metal element other than N and O).

Phosphors include a CaAlSiN.sub.3 family crystal phase, wherein the CaAlSiN.sub.3 family crystal phase comprises at least one element selected from the group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb.