A light-emitting device 1 includes: a solid-state light-emitting element 10 that radiates a laser beam L; and a wavelength converter 50 including a plurality of types of phosphors which receive the laser beam L and radiate light. The phosphors 50 included in the wavelength converter are substantially composed of a Ce.sup.3+-activated phosphor. Then, output light of the light-emitting device 1 has a light component across a wavelength range of at least 420 nm or more and less than 700 nm. The light-emitting device 1 is capable of radiating light with high color rendering properties over a wide wavelength range.

The invention relates to an inorganic scintillator material of formula Lu.sub.(2-y)Y.sub.(y-z-x)Ce.sub.xM.sub.zSi.sub.(1-v)M.sub.vO.sub.5, in which: M represents a divalent alkaline earth metal and M represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

The invention relates to an inorganic scintillator material of formula Lu.sub.(2y)Y.sub.(yzx)Ce.sub.xM.sub.zSi.sub.(1v)M.sub.vO.sub.5, in which: M represents a divalent alkaline earth metal and M represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

A scintillation compound can include a rare earth element that is in a divalent (RE.sup.2+) or a tetravalent state (RE.sup.4+). The scintillation compound can include another element to allow for better change balance. The other element may be a principal constituent of the scintillation compound or may be a dopant or a co-dopant. In an embodiment, a metal element in a trivalent state (M.sup.3+) may be replaced by RE.sup.4+ and a metal element in a divalent state (M.sup.2+). In another embodiment, M.sup.3+ may be replaced by RE.sup.2+ and M.sup.4+. In a further embodiment, M.sup.2+ may be replaced by a RE.sup.3+ and a metal element in a monovalent state (M.sup.1+). The metal element used for electronic charge balance may have a single valance state, rather than a plurality of valence states, to help reduce the likelihood that the valance state would change during formation of the scintillation compound.

A scintillation crystal can include a rare earth silicate, an activator, and a Group 2 co-dopant. In an embodiment, the Group 2 co-dopant concentration may not exceed 200 ppm atomic in the crystal or 0.25 at % in the melt before the crystal is formed. The ratio of the Group 2 concentration/activator atomic concentration can be in a range of 0.4 to 2.5. In another embodiment, the scintillation crystal may have a decay time no greater than 40 ns, and in another embodiment, have the same or higher light output than another crystal having the same composition except without the Group 2 co-dopant. In a further embodiment, a boule can be grown to a diameter of at least 75 mm and have no spiral or very low spiral and no cracks. The scintillation crystal can be used in a radiation detection apparatus and be coupled to a photosensor.

The present invention generally relates to a field emission light source and specifically to a field emission light source adapted to emit ultraviolet (UV) light. The light source has a UV emission member provided with an electron-excitable UV emitting material. The material is at least one of LuPO.sub.3:Pr.sup.3+, Lu.sub.2Si.sub.2O.sub.2:Pr.sup.3+, LaPO.sub.4:Pr.sup.3+, YBO.sub.3:Pr.sup.3+ and YPO.sub.4:Bi.sup.3+.

The invention relates to an inorganic scintillator material of formula Lu.sub.(2-y)Y.sub.y-z-x)Ce.sub.xM.sub.zSi.sub.(1-v)M.sub.vO.sub.5, in which: M represents a divalent alkaline earth metal and M represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1.

In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

A scintillation compound can include a rare earth element that is in a divalent (RE.sup.2+) or a tetravalent state (RE.sup.4+). The scintillation compound can include another element to allow for better change balance. The other element may be a principal constituent of the scintillation compound or may be a dopant or a co-dopant. In an embodiment, a metal element in a trivalent state (M.sup.3+) may be replaced by RE.sup.4+ and a metal element in a divalent state (M.sup.2+). In another embodiment, M.sup.3+ may be replaced by RE.sup.2+ and M.sup.4+. In a further embodiment, M.sup.2+ may be replaced by a RE.sup.3+ and a metal element in a monovalent state (M.sup.1+). The metal element used for electronic charge balance may have a single valance state, rather than a plurality of valence states, to help reduce the likelihood that the valance state would change during formation of the scintillation compound.

A scintillation crystal can include a rare earth silicate, an activator, and a Group 2 co-dopant. In an embodiment, the Group 2 co-dopant concentration may not exceed 200 ppm atomic in the crystal or 0.25 at in the melt before the crystal is formed. The ratio of the Group 2 concentration/activator atomic concentration can be in a range of 0.4 to 2.5. In another embodiment, the scintillation crystal may have a decay time no greater than 40 ns, and in another embodiment, have the same or higher light output than another crystal having the same composition except without the Group 2 co-dopant. In a further embodiment, a boule can be grown to a diameter of at least 75 mm and have no spiral or very low spiral and no cracks. The scintillation crystal can be used in a radiation detection apparatus and be coupled to a photosensor.

A phosphor is a phosphor composed by containing Ce.sup.3+ as an emission center in a matrix garnet compound having a garnet structure. Then, in the matrix garnet compound, a part of Ca that composes a crystal of Lu.sub.2CaMg.sub.2(SiO.sub.4).sub.3 is replaced by Mg. Moreover, a light emitting device includes the above-mentioned phosphor. In this way, it is possible to provide a garnet phosphor in which temperature quenching is reduced without largely shifting the light emission peak wavelength from that of a Lu.sub.2CaMg.sub.2(SiO.sub.4).sub.3:Ce.sup.3+ phosphor, and to provide a light emitting device using the garnet phosphor.