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 method of fabricating a light-emitting device, said method comprising:
providing a light source that emits first light;
providing a first material in optical communication with said light source, said first material substantially transparent to said first light;
dispersing particles of a second material 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 less than about said wavelength; and
dispersing particles of a third material in said first material
wherein said dispersing is such that said first material together with said particles of said second material and said third material provide a medium having a particular refractive index.
2. The method of claim 1 , wherein said light source comprises a light-emitting semiconductor device.
3. The method of claim 1 , wherein said refractive index is greater than about 1.6.
4. The method of claim 1 , further comprising disposing said first material on at least a portion of said light source.
5. The method 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.
6. The method of claim 1 , 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.
7. The method of claim 1 , wherein said particles of said second material have diameters of about 2 nm to about 50 nm.
8. The method of claim 1 , wherein said particles of said second material do not substantially absorb light of said wavelength.
9. The method of claim 1 , 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.
10. The method of claim 1 , wherein said particles of said third material have diameters less than about said wavelength of said first light.
11. The method of claim 1 , wherein said particles of said third material have diameters greater than about said wavelength of said first light.
12. The method of claim 1 , 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.
13. The method of claim 1 , wherein said refractive index of said medium approximately matches a refractive index of said third material at said wavelength of said first light.
14. The method of claim 1 , further comprising bonding an optical element to said semiconductor light-emitting device with at least a portion of said first material therebetween.
15. The method of claim 14 , wherein said optical element includes a lens.