Light-emitting devices utilizing nanoparticles
View Patent ↗Light-emitting devices are disclosed that comprise a light source emitting first light, a first material substantially transparent to and located to receive at least a portion of the first light, and particles of a second material dispersed in the first material. The second material has an index of refraction greater than an index of refraction of the first material at a wavelength of the first light. The particles of the second material have diameters less than about this wavelength. Particles of a third material may also be dispersed in the first material.
1. A light-emitting device comprising:
a light source emitting first light;
a first material substantially transparent to said first light and located to receive at least a portion of said first light; and
particles of a second material dispersed in said first material, said second material having an index of refraction greater than an index of refraction of said first material at a wavelength of said first light, said particles having diameters greater than or equal to 2 nm and less than 10 nm, wherein the diameters are less than about said wavelength and the particles are not substantially absorbing light of said wavelength; and
particles of a third material dispersed in said first material, said particles of said third material absorbing at least a portion of said first light and emitting second light having a wavelength greater than said wavelength of said first light.
2. The light-emitting device of claim 1 , wherein said light source comprises a light-emitting semiconductor device.
3. The light-emitting device of claim 1 , wherein said first material is disposed on at least a portion of said light source.
4. The light-emitting device of claim 1 , wherein said first material comprises a material selected from the group consisting of epoxies, silicones, acrylic polymers, polycarbonates, optical glasses, chalcogenide glasses, spiro compounds, and mixtures thereof.
5. The light-emitting device of claim 1 , wherein said second material comprises a material selected from the group consisting of metal oxides, II-VI compounds, III-V compounds, nitrides, nitridosilicates, and combinations thereof.
6. The light-emitting device of claim 5 , wherein said second material comprises a material selected from the group consisting of calcium oxide, cerium oxide, hafnium oxide, titanium oxide, zinc oxide, zirconium oxide, and combinations thereof.
7. The light-emitting device of claim 1 , wherein said first material together with said particles of said second material provide a medium having a refractive index greater than about 1.6.
8. The light-emitting device of claim 1 , wherein said particles of said third material have diameters greater than about said wavelength of said first light.
9. The light-emitting device of claim 1 , wherein said particles of said third material have diameters less than about said wavelength of said first light.
10. The light-emitting device of claim 1 , wherein said third material comprises a material selected from the group consisting of II-VI compounds, III-V compounds, organic dyes, yttrium aluminum garnets, gallates, aluminates, silicates, phosphates, selenides, sulfides, and mixtures thereof.
11. The light-emitting device of claim 1 , wherein said first material and said particles of said second material together provide a medium having a refractive index that approximately matches a refractive index of said third material at said wavelength of said first light.
12. The light-emitting device of claim 1 , further comprising an optical element, wherein at least a portion of said first material is disposed between said optical element and said light-emitting semiconductor device.
13. The light-emitting device of claim 12 , wherein said portion of said first material bonds said optical element to said light-emitting semiconductor device.
14. The light-emitting device of claim 12 , wherein said optical element includes a lens.
15. The light-emitting device of claim 1 , further comprising:
a submount connected to said light source; and
a leadframe connected to said submount.
16. The light-emitting device of claim 1 , wherein the second material comprises silicon.
17. A light-emitting device comprising:
a light source emitting first light;
a first material substantially transparent to said first light and located to receive at least a portion of said first light;
particles of a second material dispersed in said first material, said second material having an index of refraction greater than an index of refraction of said first material at a wavelength of said first light, said particles of said second material having diameters less than about said wavelength; and
particles of a third material dispersed in said first material, said particles of said third material having diameters greater than about said wavelength.
18. The light-emitting device of claim 17 , wherein said light source comprises a light-emitting semiconductor device.
19. The light-emitting device of claim 17 , wherein said first material is disposed on at least a portion of said light source.
20. The light-emitting device of claim 17 , wherein said first material comprises a material selected from the group consisting of epoxies, silicones, acrylic polymers, polycarbonates, optical glasses, chalcogenide glasses, spiro compounds, and mixtures thereof.
21. The light-emitting device of claim 17 , wherein said second material comprises a material selected from the group consisting of metal oxides, nitridosilicates, nitrides, II-VI compounds, III-V compounds, organic dyes, and mixtures thereof.
22. The light-emitting device of claim 17 , wherein said particles of said second material have diameters of about 2 nm to about 50 nm.
23. The light-emitting device of claim 17 , wherein said first material together with said particles of said second material provide a medium having a refractive index greater than about 1.6.
24. The light-emitting device of claim 17 , wherein said particles of said second material absorb at least a portion of said first light and emit second light having a wavelength greater than said wavelength of said first light.
25. The light-emitting device of claim 17 , wherein said third material comprises a material selected from the group consisting of yttrium aluminum garnets, gallates, aluminates, silicates, phosphates, selenides, sulfides, and mixtures thereof.
26. The light-emitting device of claim 17 , wherein said particles of said third material absorb at least a portion of said first light and emit second light having a wavelength greater than said wavelength of said first light.
27. The light-emitting device of claim 17 , wherein said particles of said second material absorb a portion of said first light and emit second light having a wavelength greater than said wavelength of first light, and said particles of said third material absorb another portion of said first light and emit third light having a wavelength greater than said wavelength of first light.
28. The light-emitting device of claim 17 , wherein said first material and said particles of said second material together provide a medium having a refractive index that approximately matches a refractive index of said third material at said wavelength of said first light.
29. The light-emitting device of claim 17 , further comprising an optical element, wherein at least a portion of said first material is disposed between said optical element and said light-emitting semiconductor device.
30. The light-emitting device of claim 29 , wherein said portion of said first material bonds said optical element to said light-emitting semiconductor device.
31. The light-emitting device of claim 29 , wherein said optical element includes a lens.
32. The light-emitting device of claim 17 , further comprising:
a submount connected to said light source; and
a leadframe connected to said submount.