A wavelength converter 100 includes: a first phosphor 1 composed of an inorganic phosphor activated by Ce.sup.3+; and a second phosphor 2 composed of an inorganic phosphor activated by Ce.sup.3+ and different from the first phosphor. At least one of the first phosphor and the second phosphor is particulate. The first phosphor and the second phosphor are bonded to each other by at least one of a chemical reaction in a contact portion between the compound that constitutes the first phosphor and a compound that constitutes the second phosphor and of adhesion between the compound that constitutes the first phosphor and the compound that constitutes the second phosphor.

Codoped lutetium-based oxyorthosilicate scintillators (e.g., lutetium oxyorthosilicase (LSO) and lutetium-ytrrium oxyorthosilicate (LYSO) scintillators) codoped with transition metal ions (e.g., Cu.sup.2+) are described. The codoping can alter one or more optical and/or scintillation property of the scintillator material. For example, the codoping can increase scintillation light yield and/or decrease scintillation decay time. Radiation detectors comprising the scintillators, methods of detecting high energy radiation using the radiation detectors, and methods of altering one or more scintillation and/or optical properties of a lutetium-based oxyorthosilicate scintillator are also described.

A silicate-based lanthanide ion doped material converts electromagnetic radiation energy of a longer wavelength of below 530 nm to electromagnetic radiation energy of shorter wavelengths in the range of 220 to 425 nm. The silicate-based material is a crystalline silicate material doped with lanthanide ions selected from praseodymium, gadolinium, erbium, and neodymium. For co-doping, at least two of the lanthanide ions are used. The silicate-based material is obtainable from a blend comprising salts and an organic solvent, followed by specific calcination processes and tribological impacts to adjust particle size and to increase the crystallinity of the particles. The silicate-based material can be used to inactivate microorganisms or cells covering a surface containing the silicate-based material under exposure of electromagnetic radiation energy of a longer wavelength of below 500 nm.

A garnet is doped with a lanthanide ion selected from praseodymium, gadolinium, erbium, and neodymium. For co-doping, at least two of the lanthanide ions are selected. The lanthanide ion doped garnet converts electromagnetic radiation energy of a longer wavelength of below 530 nm to electromagnetic radiation energy of shorter wavelengths in the range of 220 to 425 nm. The garnet is crystalline and is obtainable from a mixture of salts or oxides of the components, in the presence of a chelating agent, that are dissolved in acid. This is followed by a specific calcination process to produce the garnet and, optionally, to adjust particle size and increase the crystallinity of the particles. The garnet can be used to inactivate microorganisms or cells covering a surface containing silicate-based material under exposure of electromagnetic radiation energy of a longer wavelength of below 500 nm.

The invention refers to a composite wavelength converter (1) for an LED (100), comprising a substrate (10) and an epitaxial film (20) formed by liquid phase epitaxy on the top and bottom of the substrate (10). Furthermore, the invention refers to a method of preparation of a composite wavelength converter (1) for an LED (100). Furthermore, the invention refers to a white LED light source comprising an LED (100) and an inventive composite wavelength converter (1) mounted on a light emitting surface of the LED (100).

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 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 curable composition for production of coatings having an antimicrobial property, contains at least one film-forming polymer, optionally at least one additive and/or at least one curing agent, and at least one up-conversion phosphor of the general formula (I): A.sub.1-x-y-zB*.sub.yB.sub.2SiO.sub.4:Ln.sup.1.sub.x,Ln.sup.2.sub.z. In the general formula (I), x=0.0001-0.0500; z=0.0000 or z=0.0001 to 0.3000 with the proviso that: y=x+z; A is selected from Mg, Ca, Sr and Ba; B is selected from Li, Na, K, Rb and Cs; B* is selected from Li, Na and K; and preferably B and B* are not the same. Additionally, Ln.sup.1 is selected from praseodymium (Pr), erbium (Er), and neodymium (Nd); and Ln.sup.2 is gadolinium (Gd). The phosphor has been prepared using at least one halogen-containing flux.

A target for ultraviolet light generation comprises a substrate adapted to transmit ultraviolet light therethrough and a light-emitting layer, disposed on the substrate, for generating ultraviolet light in response to an electron beam. The light-emitting layer includes a powdery or granular oxide crystal containing Lu and Si doped with an activator (e.g., Pr:LPS and Pr:LSO crystals).

Codoped lutetium-based oxyorthosilicate scintillators (e.g., lutetium oxyorthosilicase (LSO) and lutetium-ytrrium oxyorthosilicate (LYSO) scintillators) codoped with transition metal ions (e.g., Cu.sup.2+) are described. The codoping can alter one or more optical and/or scintillation property of the scintillator material. For example, the codoping can increase scintillation light yield and/or decrease scintillation decay time. Radiation detectors comprising the scintillators, methods of detecting high energy radiation using the radiation detectors, and methods of altering one or more scintillation and/or optical properties of a lutetium-based oxyorthosilicate scintillator are also described.