Spatial localization of light-generating portions in LEDs
Light-emitting devices (e.g., LEDs) and methods associated with such devices are provided. In some embodiments, the device includes a distribution of light-generating portions (including active regions) that are spatially localized and separated (e.g., horizontally or vertically) from one or more patterned light extraction portions. This arrangement can allow light generated by the device to propagate and pass through regions of low absorption (e.g., light-extraction portions) rather than in regions of high absorption (e.g., light-generating portions), which can enhance light emission.
1. A light-emitting device comprising:
a distribution of light-generating portions including respective active regions configured to generate light, the light-generating portions being devoid of a surface with a dielectric function that varies spatially according to a pattern; and
at least one light extraction portion that allows generated light to pass therethrough, wherein the at least one light extraction portion is devoid of a light-generating portion including an active region, wherein the at least one light extraction portion includes a plurality of surface features designed to enhance light extraction, wherein at least 50% of the light generated is emitted through a surface of the at least one light extraction portion.
2. A light-emitting device of claim 1 , wherein the at least one light-extraction portion comprises a dielectric function that varies spatially according to a first pattern.
3. A light-emitting device of claim 2 , wherein the first pattern is a photonic lattice.
4. A light-emitting device of claim 1 , further comprising a plurality of light extraction portions.
5. A light-emitting device of claim 4 , wherein the light-generating portions are laterally separated from the plurality of light extraction portions.
6. A light-emitting device of claim 4 , wherein the plurality of light extraction portions have a plurality of features that vary spatially according to a pattern.
7. A light-emitting device of claim 6 , wherein the features are holes in a surface of the plurality of light extraction portions.
8. A light-emitting device of claim 1 , wherein at least a part of a light-generating portion is not positioned above or below the at least one light extraction portion.
9. A light-emitting device of claim 1 , wherein at least one light-generating portion is not positioned above or below the at least one light extraction portion.
10. A light-emitting device of claim 1 , wherein at least one light-generating portion has a cross-sectional dimension equal to or less than a cross-sectional dimension of at least one light extraction portion.
11. A light-emitting device of claim 1 , wherein the at least one light extraction portion comprises an optically reflective region.
12. A light-emitting device of claim 11 , wherein the optically reflective region comprises a focusing element.
13. A light-emitting device of claim 11 , wherein the optically reflective region comprises an optically reflective layer.
14. The light-emitting device of claim 1 , wherein at least one light-generating portion has a cross-sectional dimension greater than five times a cross-sectional dimension of a surface feature of the at least one light extraction portion.
15. The light-emitting device of claim 1 , wherein the at least one light extraction portion has a cross-sectional dimension greater than five times a cross-sectional dimension of a surface feature of the at least one light extraction portion.
16. The light-emitting device of claim 1 , wherein at least 70% of the light generated is emitted through a surface of the at least one light extraction portion.
17. A light-emitting device comprising:
a distribution of light-generating portions including respective active regions configured to generate light, the light-generating portions being devoid of a surface with a dielectric function that varies spatially according to a pattern; and at least one light extraction portion that allows generated light to pass therethrough, wherein at least a part of the at least one light extraction portion comprises a plurality of features that form a dielectric function that varies spatially according to a pattern and is devoid of a light-generating portion including an active region, wherein at least 50% of the light generated is emitted through a surface of the at least one light extraction portion.
18. A light-emitting device of claim 17 , wherein the pattern is a photonic lattice.
19. A light-emitting device of claim 17 , further comprising a plurality of light extraction portions.
20. A light-emitting device of claim 17 , wherein at least one light-generating portion has a cross-sectional dimension equal to or greater than a cross-sectional dimension of the at least one light extraction portion.
21. A light-emitting device comprising:
a distribution of light-generating portions including respective active regions configured to generate light, each light-generating portion including an active region, and each light-generating portion being devoid of a surface with a dielectric function that varies spatially according to a pattern; and
at least one light extraction portion including an emission surface that allows generated light to pass therethrough, wherein at least a part of an active region is not positioned above or below the emission surface, and wherein the at least one light extraction portion includes a plurality of surface features on the emission surface designed to enhance light extraction, wherein at least 50% of the light generated is emitted through a surface of the at least one light extraction portion.