Abstract: The invention relates to a converter system, for instance for a light emitting device, comprising: —a first material, which comprises, preferably essentially consists of an emitting material, emitting a color of interest, and is essentially free of sensitizer material, —a second sensitizer material, which is essentially free of the first material and absorbs light (is excitable) in the wavelength range of interest and its emission spectrum overlaps at least partly with one or more excitation bands of the first material.

Abstract: The invention provides Y2O3:RE nanoparticles having a cubic crystal structure, wherein RE is a trivalent rare earth metal ion. The invention further provides a method of preparing Y2O3:RE nanoparticles, comprising: a) providing a mixture comprising (i) an yttrium salt and/or yttrium alkoxide, (ii) a rare earth metal salt and/or rare earth metal alkoxide, and (iii) an organic solvent; b) optionally, subjecting the mixture to a pre-treatment step which comprises heating the mixture at a temperature of at least 80° C. and/or at a temperature such that crystal water and/or organic impurities are removed, c) heating the mixture at a temperature between 220° C. and 320° C. and/or at a temperature such that a precursor complex forms; d) subjecting the mixture to a precipitation stage, wherein a precipitate forms, said precipitation stage preferably comprising allowing the mixture to cool and/or adding an antisolvent to the mixture; and e) heating the precipitate at a temperature between 600° C. and 900° C.

Abstract: The invention relates to lighting emitting devices and systems comprising a luminescent composition, said luminescent composition comprising: (i) a first emitting material, said first emitting material having a host lattice doped with EU3+ ions; (ii) a second emitting material, said second emitting material having a host lattice doped with Tb3+ ions; and (iii) sensitizer material, which sensitizer material is excitable in the violet-to-blue (400 to 480 nm) wavelength range and has an emission spectrum which overlaps at least partly with one or more excitation bands of the first emitting material and with which overlaps at least partly with one or more excitation bands of the second emitting material.

Abstract: A lighting arrangement for general lighting, comprising a first light source Oadapted to emit a first light substantially only in a first predetermined spectrum in a range from 615 nm to 690 nm, one or more driver circuits adapted to provide a first pulsed driving current to the first light source for producing the first light pulsing with a first peak radiant power in the first predetermined spectrum sufficient to induce a photo-biomodulation response in a human body, and a second light source adapted to emit a second light, the second light source being capable of emitting at least 250 lumens.

Abstract: The invention provides a method for preparing a luminescent composition, said method comprising: (a) providing a first luminescent material or a precursor thereof, said first luminescent material being capable of emitting light in a first wavelength range; (b) providing a second luminescent material or a precursor thereof, said second luminescent material being capable of absorbing light in a second wavelength range and having an emission spectrum which overlaps at least partly with one or more of excitation bands of said first luminescent material; and (c) mixing said first luminescent material or said precursor thereof and said second luminescent material or said precursor thereof, wherein said method further comprises: (I) preparing a mixture comprising (i) said first luminescent material or said precursor thereof and/or said second luminescent material or said precursor thereof and (ii) a salt; and (If) heating said mixture at a temperature of 300° C. or more.

Abstract: The invention relates to a converter system, for instance for a light emitting device, comprising: a first material, which comprises, preferably essentially consists of an emitting material, emitting a color of interest, and is essentially free of sensitizer material, a second sensitizer material, which is essentially free of the first material and absorbs light (is excitable) in the wavelength range of interest and its emission spectrum overlaps at least partly with one or more excitation bands of the first material.

Abstract: The present invention relates to a light emitting device comprising a red-emitting Eu3+ material and green emitting Ce3+ material which are matched so that the resulting white light has an increased lumen equivalent of radiation for a given color rendering index than with the prior art.

Abstract: The invention relates to a converter system, for instance for a light emitting device, comprising: —a first material, which comprises, preferably essentially consists of an emitting material, emitting a color of interest, and is essentially free of sensitizer material, —a second sensitizer material, which is essentially free of the first material and absorbs light (is excitable) in the wavelength range of interest and its emission spectrum overlaps at least partly with one or more excitation bands of the first material.

Abstract: The present invention relates to a light emitting device comprising a red-emitting Eu3+ material and green emitting Ce3+ material which are matched so that the resulting white light has an increased lumen equivalent of radiation for a given color rendering index than with the prior art.

Abstract: The invention relates to a converter system, for instance for a light emitting device, comprising: —a first material, which comprises, preferably essentially consists of an emitting material, emitting a color of interest, and is essentially free of sensitizer material, —a second sensitizer material, which is essentially free of the first material and absorbs light (is excitable) in the wavelength range of interest and its emission spectrum overlaps at least partly with one or more excitation bands of the first material.