LED emitters with integrated nano-photonic structures to enhance EQE
A device, system and method for producing enhanced external quantum efficiency (EQE) LED emission are disclosed. The device, system and method include a patterned layer configured to transform surface modes into directional radiation, a semiconductor layer formed as a III/V direct bandgap semiconductor to produce radiation, and a metal back reflector layer configured to reflect incident radiation. The patterned layer may be one-dimensional, two-dimensional or three-dimensional. The patterned layer may be submerged within the semiconductor layer or within the dielectric layer. The semiconductor layer is p-type gallium nitride (GaN). The patterned layer may be a hyperbolic metamaterials (HMM) layer and may include Photonic Hypercrystal (PhHc), or may be a low or high refractive index material or may be a metal.
1. A device comprising:
a light emitting semiconductor layer comprising multiple quantum wells;
a nano-photonic structure disposed below the light emitting semiconductor layer and arranged to couple near field radiation from the multiple quantum wells into surface electronic states of the nano-photonic structure; and
a lattice structure disposed between the nano-photonic structure and the multiple quantum wells and arranged to out-couple radiation from the surface electronic states of the nano-photonic structure.
2. The device of claim 1 , wherein the lattice structure is not in direct contact with the nano-photonic structure.
3. The device of claim 1 , wherein the lattice structure is embedded in a dielectric material.
4. The device of claim 1 , wherein the lattice structure is in direct contact with the light emitting semiconductor layer.
5. The device of claim 1 , wherein the lattice structure is not in direct contact with the light emitting semiconductor layer.
6. The device of claim 5 , further comprising a transparent conductive layer between the lattice structure and the light emitting semiconductor layer.
7. The device of claim 1 , wherein the lattice structure is a metal nano-antenna array.
8. The device of claim 1 , wherein the lattice structure is a dielectric nano-antenna array.
9. The device of claim 1 , wherein the nano-photonic structure is not in direct contact with the light emitting semiconductor layer.
10. The device of claim 1 , wherein the nano-photonic structure is a photonic crystal.
11. The device of claim 1 , further comprising a transparent conductive layer between the lattice structure and the nano-photonic structure.
12. The device of claim 1 , wherein the nano-photonic structure consists of dielectric material.
13. The device of claim 1 , wherein the nano-photonic structure is a plasmonic layer consisting of metal.
14. The device of claim 1 , wherein the lattice structure is an array and the transparent conductive layer is etched at locations of the array to permit the array to directly contact the light emitting semiconductor structure.
15. A device comprising:
a light emitting semiconductor layer comprising multiple quantum wells;
a transparent conductive layer and a dielectric layer below the light emitting semiconductor layer;
a nano-photonic structure disposed below the transparent conductive layer and arranged to couple near field radiation from the multiple quantum wells into surface electronic states of the nano-photonic structure; and
a lattice structure disposed between the dielectric material and the light emitting semiconductor layer and arranged to out-couple radiation from the surface electronic states of the nano-photonic structure to form light output, the lattice structure in direct contact with the dielectric material and the light emitting semiconductor layer without being in direct contact with the nano-photonic structure.