Encapsulated quantum dots in porous particles

Abstract

The invention provides a process for the production of a (particulate) luminescent material comprising particles, especially substantially spherical particles, having a porous inorganic material core with pores, especially macro pores, which are at least partly filled with a polymeric material with luminescent quantum dots embedded therein, wherein the process comprises (i) impregnating the particles of a particulate porous inorganic material with pores with a first liquid (“ink”) comprising the luminescent quantum dots and a curable or polymerizable precursor of the polymeric material, to provide pores that are at least partly filled with said luminescent quantum dots and curable or polymerizable precursor; and (ii) curing or polymerizing the curable or polymerizable precursor within pores of the porous material, as well as a product obtainable thereby.

1 . A luminescent material comprising particles having a porous inorganic material core wherein the pores are at least partly filled with polymeric material with luminescent quantum dots embedded therein. 
     
     
         2 . A luminescent material according to  claim 1 , wherein the particles comprise an encapsulation encapsulating at least a part of the core. 
     
     
         3 . A luminescent material according to  claim 2 , wherein the encapsulation comprises a coating that at least partly coats the particles with an inorganic coating selected from the group consisting of a silicon containing oxide, an aluminum containing oxide, a zirconium containing oxide, a glass, a titanium containing oxide, a hafnium containing oxide and an yttrium containing oxide. 
     
     
         4 . A luminescent material according to  claim 2 , wherein the encapsulation comprises a multi-layer coating that coats the particles, wherein the multi-layer coating comprises an organic polymer coating and an inorganic coating, or at least two coatings selected from the group of a silicon containing oxide, an aluminum containing oxide, a zirconium containing oxide, a glass, a titanium containing oxide, a hafnium containing oxide and an yttrium containing oxide. 
     
     
         5 . The luminescent material according to  claim 1 ,
 wherein the particles have particle sizes in the range of 1-500 μm,   wherein the porous inorganic material comprises one or more of a porous silica, a porous alumina, a porous glass, a porous zirconia, and a porous titania,   wherein the pores have mean pore sizes in the range of 0.1-10 μm,   wherein the polymeric material comprises one or more of an acrylate, silicone, or epoxy type polymer,   wherein the encapsulation comprises an inorganic coating.   
     
     
         6 . A wavelength converter comprising a light transmissive solid matrix with the luminescent material according to  claim 1 . 
     
     
         7 . The wavelength converter according to  claim 6 , further comprising a second luminescent material. 
     
     
         8 . A lighting device comprising:
 a light source configured to generate light source light, the luminescent material according to  claim 1  wherein the luminescent material is configured to convert at least part of the light source light into visible luminescent quantum dot light.   
     
     
         9 . The lighting device according to  claim 8 , wherein the luminescent quantum dots are selected from the group consisting of core-shell quantum dots, with the core selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, GaN, GaP, GaAs, AlN, AlP, AlAs, InN, InP, InGaP, InAs, GaNP, GaNAs, GaPAs, AlNP, AlNAs, AlPAs, InNP, InNAs, InPAs, GaAlNP, GaAlNAs, GaAlPAs, GaInNP, GaInNAs, GaInPAs, InAlNP, InAlNAs, and InAlPAs nanoparticles. 
     
     
         10 . The lighting device according to  claim 8 , comprising a wavelength converter comprising a light transmissive solid matrix, the wavelength converter, arranged at a zero or non-zero distance from the light source,
 wherein the lighting device further comprises a second luminescent material,   wherein the second luminescent material under excitation with light has another wavelength distribution of the luminescence than the luminescent quantum dots.