HIGHLY REFRACTIVE, TRANSPARENT THERMAL CONDUCTORS FOR BETTER HEAT DISSIPATION AND LIGHT EXTRACTION IN WHITE LEDS
A lighting apparatus includes a light source and a light conversion layer disposed proximate the light source, the light conversion layer comprising a plurality of quantum dots (QDs) or phosphors, and a plurality of transparent thermally conductive particles, embedded in a matrix material to improve heat dissipation.
1 . A lighting apparatus, comprising:
a light source; and
a light conversion layer disposed proximate the light source, the light conversion layer comprising a plurality of quantum dots (QDs) or phosphors, and a plurality of transparent thermally conductive particles, embedded in a matrix material.
2 . The lighting device of claim 1 , wherein the light source is selected from one of a group of light sources consisting of: a light emitting diode (LED) light source, a blue LED light source, an LED chip-based light source, and a ultraviolet (UV) LED light source.
3 . The lighting device of claim 1 , wherein the light conversion layer is adjacent to the light source.
4 . The lighting device of claim 1 , wherein the light conversion layer is an optical element in one of a module, lamp, or luminaire, that is separate and remote from the light source.
5 . The lighting device of claim 1 , further comprising a reflective, thermally conductive heatsink, wherein the light conversion layer is deposited onto a surface of the heatsink.
6 . The lighting device of claim 5 , wherein the heatsink is proximate to the light source.
7 . The lighting device of claim 1 , wherein the plurality of transparent thermally conductive particles is highly thermally conductive.
8 . The lighting device of claim 1 , wherein the plurality of transparent thermally conductive particles is highly refractive.
9 . The lighting device of claim 8 , wherein an index of refraction of the plurality of transparent thermally conductive particles is higher than an index of refraction of the matrix material.
10 . The lighting device of claim 9 , wherein the plurality of transparent thermally conductive particles is selected from a group of materials consisting of: natural diamond, synthetic diamond, synthetic monocrystalline diamond, amber cubic boron nitride, hexagonal boron nitride, silicon carbide- 6 H, silicon carbide- 4 H, silicon carbide- 3 C, and aluminum nitride.
11 . The lighting device of claim 9 , wherein the plurality of transparent thermally conductive particles is selected from a group of insulator coating materials consisting of: silica (SiO x ), titanium oxide (TiO x ), zirconium oxide (ZrO x ), alumina (AlO x ), and hafnia (HfO x ).
12 . The lighting device of claim 8 , wherein the plurality of transparent thermally conductive particles is selected from a group of particles having attributes consisting of: high thermal conductivity, low electrical conductivity, high index of refraction, high transparency, low color, high crystallinity, a smooth surface, and a small particle size.
13 . A multiple quantum dot (QD) device, comprising:
a matrix material; and
a plurality of quantum dots (QDs) embedded in the matrix material;
a plurality of transparent thermally conductive particles embedded in the matrix material.
14 . The multiple QD device of claim 13 , wherein the plurality of transparent thermally conductive particles is highly thermally conductive.
15 . The multiple QD device of claim 13 , wherein the plurality of transparent thermally conductive particles is highly refractive.
16 . The multiple QD device of claim 15 , wherein an index of refraction of the plurality of transparent thermally conductive particles is higher than an index of refraction of the matrix material.
17 . The multiple QD device of claim 13 , wherein the plurality of transparent thermally conductive particles is selected from a group of materials consisting of: natural diamond, synthetic diamond, synthetic monocrystalline diamond, amber cubic boron nitride, hexagonal boron nitride, silicon carbide- 6 H, silicon carbide- 4 H, silicon carbide- 3 C, and aluminum nitride.
18 . The multiple QD device of claim 13 , wherein the plurality of transparent thermally conductive particles is selected from a group of insulator coating materials consisting of: silica (SiO x ), titanium oxide (TiO x ), zirconium oxide (ZrO x ), alumina (AlO x ), and hafnia (HfO x ).
19 . The multiple QD device of claim 13 , wherein the plurality of transparent thermally conductive particles is selected from a group of particles having attributes consisting of: high thermal conductivity, low electrical conductivity, high index of refraction, high transparency, low color, high crystallinity, a smooth surface, and a small particle size.
20 . A method to form a transparent, thermally conductive, quantum dot (QD) composite, comprising:
embedding a plurality of quantum dots to a matrix material; and
embedding a plurality of transparent, thermally conductive particles to the matrix material.
21 . The method of claim 20 , further comprising casting the composite on to a light-emitting diode (LED) chip including a heat sink such that the composite surrounds the LED and makes contact with the heat sink.
22 . The method of claim 21 , further comprising curing the composite under vacuum at 150 degrees centigrade for two hours.