Lighting devices with prescribed colour emission

Patent metadata

Field	Value
Publication number	US-9868901-B2
Application number	US-201514799793-A
Country	US
Kind code	B2
Filing date	Jul 15, 2015
Priority date	Jan 28, 2010
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

Optical conversion layers based on semiconductor nanoparticles for use in lighting devices, and lighting devices including same. In various embodiments, spherical core/shell seeded nanoparticles (SNPs) or nanorod seeded nanoparticles (RSNPs) are used to form conversion layers with superior combinations of high optical density (OD), low re-absorbance and small FRET. In some embodiments, the SNPs or RSNPs form conversion layers without a host matrix. In some embodiments, the SNPs or RSNPs are embedded in a host matrix such as polymers or silicone. The conversion layers can be made extremely thin, while exhibiting the superior combinations of optical properties. Lighting devices including SNP or RSNP-based conversion layers exhibit energetically efficient superior prescribed color emission.

First claim

The invention claimed is:

1. A lighting device comprising a light source for producing exciting light of a first spectral range, and at least one conversion layer located at an output of said light source, the at least one conversion layer comprises semiconductor seeded nanoparticles (SNPs) embedded in a polymer host matrix, said SNPs comprising SNPs having material composition, geometry and shape selected to convert said exciting light of the first spectral range into light of at least one second wavelength comprising three or more primary colours with emission bandwidth having full width half max (FWHM) of below 60 nm for emission in said three or more primary colours, said lighting device thereby emitting light of said at least one second wavelength.

2. The lighting device of claim 1 , wherein the conversion layer comprises a host matrix, said host matrix comprising said SNPs embedded therein and comprising a medium having predetermined refractive index and surface roughness selected to enhance extraction of light of said second wavelength emitted by the SNPs.

3. The lighting device of claim 2 , wherein said host matrix comprises diffusive particles enhancing light scattering within the conversion layer.

4. The lighting device of claim 1 , wherein said SNPs comprise rod shaped SNPs (RSNPs).

5. The lighting device of claim 4 , wherein said RSNPs have selected diameters and lengths to provide said desired light of the at least one second wavelength.

6. The lighting device of claim 4 , wherein said RSNP have diameter below 10 nm and a length between 6 nm and 500 nm.

7. The lighting device of claim 1 , wherein said at least one conversion layer comprises one or more sub-layers comprising SNPs of different types.

8. The lighting device of claim 1 , wherein said SNPs comprise a core material selected from at least one of the following: CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, GaAs, GaP, GaAs, GaSb, HgS, HgSe, HgTe, InAs, InP, InSb, AlAs, AlP, AlSb, Cu 2 S, Cu 2 Se, CuInS 2 , CuInSe 2 , Cu 2 (ZnSn)S 4 and Cu 2 (InGa)S 4 .

9. The lighting device of claim 1 , wherein said SNPs comprise a shell material selected from at least one of the following: CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, GaAs, GaP, GaAs, GaSb, GaN, HgS, HgSe, HgTe, InAs, InP, InSb, AlAs, AlP, AlSb, Cu 2 S, Cu 2 Se, CuInS 2 , CuInSe 2 , Cu 2 (ZnSn)S 4 and Cu 2 (InGa)S 4 .

10. The lighting device of claim 1 , further comprising at least one optical filter located in optical path between the light source and the at least one conversion layer; said at least one optical filter being configured for transmitting exciting light of the first spectral range and reflecting emitted light of the at least one second wavelength range.

11. The lighting device of claim 1 , further comprising a transmissive optical element configured for extracting emitted light from the at least one conversion layer towards a desired direction.

12. The lighting device of claim 1 , wherein said light source comprises at least one Light Emitting Diode (LED) configured for providing monochromatic emission of UV or blue wavelength range.

13. The lighting device of claim 1 , configured for use as backlight unit for display device.

14. The lighting device of claim 1 , wherein said at least one conversion layer comprises SNPs embedded in a host matrix, said conversion layer being characterized in loading ratio of SNPs in said host matrix being above 40% (possible between 40% and 100%).

15. A lighting device comprising a light source for producing exciting light of a first spectral range, and at least one conversion layer located at an output of said light source, the at least one conversion layer comprises semiconductor seeded nanoparticles (SNPs) having material composition, geometry and shape selected to convert said exciting light of the first spectral range into light of at least one second wavelength, said lighting device thereby emitting light of said at least one second wavelength, wherein said at least one conversion layer is configured and operable as a spectral antenna to convert said exciting light of the first spectral range into light of the second wavelengths having balance between different spectral regions such that said light of the second wavelengths is characterized by desired correlated colour temperature (CCT) and color rendering index (CRI).

16. A lighting device comprising a light source for producing exciting light of a first spectral range, and at least one conversion layer located at an output of said light source, the at least one conversion layer comprises semiconductor seeded nanoparticles (SNPs) having material composition, geometry and shape selected to convert said exciting light of the first spectral range into light of at least one second wavelength, said lighting device thereby emitting light of said at least one second wavelength, wherein said light source is configured to provide colour mixture light having correlated colour temperature (CCT) in the range of 5000-10000K, said at least one conversion layer being configured for converting said colour mixture light to provide emitted light having CCT in the range of 2500-6000K.

Assignees

• Yissum Res Dev Co Of Hebrew Univ Jerusalem Ltd
• Qlight Nanotech Ltd

Inventors

• Arbell Hagai
• Banin Uri

Classifications

• C09K11/7706

  Aluminates · CPC title

• C09K11/025

  non-luminescent particle coatings or suspension media · CPC title

• H01L33/505

  Electricity · mapped topic

• C09K11/56

  containing sulfur · CPC title

• Y10S977/95

  Electromagnetic energy · CPC title