Abstract:
A laminated composite includes a wavelength-converting layer and a non-emissive blocking layer, wherein the emissive layer includes a garnet host material and an emissive guest material, and the non-emissive blocking layer includes a non-emissive blocking material. The metallic element constituting the non-emissive blocking material has an ionic radius which is less than about 80% of an ionic radius of an A cation element when the garnet or garnet-like host material is expressed as Α 3 Β 5 O 12 and/or an element constituting the emissive guest material, and the non-emissive blocking layer is substantially free of the emissive guest material migrated through an interface between the emissive layer and the non-emissive blocking layer.
Abstract:
Some phosphor powders can be difficult to form into ceramic compacts because they are difficult to sinter. As described herein, phosphor powders that can degrade under conventional sintering temperatures can be sintered by heating the powder at a lower temperature, such as less than 800°C, while the powder is under greater than atmospheric pressure, such as at least 0.05 GPa. Phosphor ceramic compacts prepared by this method, and light-emitting devices incorporating these phosphor ceramic compacts, are also described.
Abstract:
Disclosed herein are phosphor compositions having high gadolinium concentrations. Some embodiments include a thermally stable ceramic body comprising an emissive layer, wherein said emissive layer comprises a compound represented by the formula (A I-x-z Gd x D z ) 3 B 5 0 12 , wherein: D is a first dopant selected from the group consisting of Nd, Er, Eu, Mn, Cr, Yb, Sm, Tb, Ce, Pr, Dy, Ho, Lu and combinations thereof; A is selected from the group consisting of Y, Lu, Ca, La, Tb, and combinations thereof; B is selected from the group consisting of Al, Mg, Si, Ga, In, and combinations thereof; x is in the range of about 0.20 and about 0.80; and z is in the range of about 0.001 and about 0.10. Also disclosed are thermally stable ceramic bodies that can include the composition of formula I. Methods of making the ceramic body and a lighting device including the ceramic body are also disclosed.
Abstract:
Some embodiments disclosed herein include a lighting apparatus having a composite. The composite may include a first emissive layer and a second emissive layer. The first emissive layer may include a first garnet phosphor having a common dopant. The second emissive layer may include a second garnet phosphor having the common dopant. In some embodiments, the first emissive layer and the second emissive layer are fixed together. Some embodiments disclosed herein include efficient and economic methods of making the composite. The method may include, in some embodiments, sintering an assembly that includes pre-cursor materials for the first emissive layer and the second emissive layer.
Abstract:
A ceramic composite laminate includes a wavelength-converting layer and a non-emissive layer, wherein the ceramic composite laminate has a wavelength conversion efficiency (WCE) of at least 0.650. The ceramic composite laminate can also include a wavelength-converting ceramic layer comprising an emissive material and a scattering material, wherein the laminated composite has a total transmittance of between about 40% to about 85%. The wavelength-converting layer may be formed from plasma YAG:Ce powder.
Abstract:
Some embodiments provide luminescent ceramics which have a lower amount of dopant than conventional luminescent ceramics. In some embodiments, the luminescent ceramic comprises a host material comprising a rare earth element and at least one rare earth dopant, wherein the rare earth dopant may be about 0.01% to 0.5% of the rare earth atoms present in the material. Some embodiments provide luminescent ceramic comprising: a polycrystalline phosphor represented by the formula (A 1-x E x ) 3 B 5 O 12 . Some embodiments provide a light-emitting device comprising a luminescent ceramic disclosed herein.
Abstract:
Electric sintering of precursor materials to prepare phosphor ceramics is described herein. The phosphor ceramics prepared by electric sintering may be incorporated into devices such as light-emitting devices, lasers, or for other purposes.