Solid-state transducer assemblies with remote converter material for improved light extraction efficiency and associated systems and methods
Solid state transducer (“SST”) assemblies with remote converter material and improved light extraction efficiency and associated systems and methods are disclosed herein. In one embodiment, an SST assembly has a front side from which emissions exit the SST assembly and a back side opposite the front side. The SST assembly can include a support substrate having a forward-facing surface directed generally toward the front side of the SST assembly and an SST structure carried by the support substrate. The SST structure can be configured to generate SST emissions. The SST assembly can further include a converter material spaced apart from the SST structure. The forward-facing surface and the converter material can be configured such that at least a portion of the SST emissions that exit the SST assembly at the front side do not pass completely through the converter material.
1. A solid-state transducer (SST) assembly having a front side from which emissions exit the SST assembly and a back side opposite the front side, the SST assembly comprising:
a support substrate having a forward-facing surface and an opening from which emissions exit the SST assembly;
an SST structure carried by the support substrate and configured to generate SST emissions; and
a wavelength converter material spaced apart from the SST structure, the wavelength converter material having a thickness, wherein the forward-facing surface and the wavelength converter material are configured such that at least a portion of the SST emissions that exit the SST assembly at the front side do not pass completely through the thickness of the wavelength converter material, wherein the thickness of the wavelength converter material is such that more SST emissions reflect from an outer surface of the wavelength converter material than pass through the wavelength converter material.
2. The SST assembly of claim 1 wherein:
the support substrate includes a flanged portion at an inner circumference of the support substrate, the flanged portion having a support surface carrying the SST structure, wherein the support surface and the SST structure face generally toward the back side of the SST structure;
the forward-facing surface extends from the flanged portion toward the back side of the SST assembly, the forward-facing surface being shaped to direct SST emissions through the opening;
the forward-facing surface includes a reflective material;
the wavelength converter material is on the reflective material at the forward-facing surface; and
the SST structure includes a first semiconductor material comprising N-type gallium nitride (N-GaN), a second semiconductor material comprising a P-type gallium nitride (P-GaN), and an active region comprising indium gallium nitride (InGaN), the active region being between the first and second semiconductor materials.
3. The SST assembly of claim 1 wherein:
the SST structure faces generally toward the back side of the SST assembly;
the forward-facing surface is positioned toward the back side of the SST assembly relative to the SST structure;
the wavelength converter material is on the forward-facing surface; and
the SST assembly is configured such that the SST emissions initially travel generally toward the back side of the SST assembly where at least a portion of the SST emissions strike the outer surface of the wavelength converter material and reflect toward the front side to exit the SST assembly.
4. The SST assembly of claim 3 wherein the forward-facing surface has a substantially semicircular cross-sectional shape.
5. The SST assembly of claim 1 wherein:
the support substrate includes a support surface that carries the SST structure and faces generally toward the front side of the SST assembly;
the forward-facing surface is spaced laterally outward from the support surface and is angled toward the front side;
the forward-facing surface comprises a reflective material;
the converter material is on the reflective material of the forward-facing surface; and
the SST assembly further includes a cover feature on the SST structure, the cover feature being configured to direct at least a portion of the SST emissions generally toward the forward-facing surface.
6. The SST assembly of claim 1 , further comprising a cover feature on the SST structure, the cover feature being shaped to direct SST emissions generally toward the forward-facing surface.
7. The SST assembly of claim 6 wherein the cover feature comprises a first lobe configured to direct a first portion of the SST emissions laterally outward in a first direction and a second lobe configured to direct a second portion of the SST emissions laterally outward in a second direction different from the first direction.
8. A solid-state transducer (SST) assembly having a front side from which emissions exit the SST assembly and a back side opposite the front side, the SST assembly comprising:
a support substrate having a forward-facing surface and an opening from which emissions exit the SST assembly, wherein the forward-facing surface comprises a reflective material;
an SST structure carried by the support substrate and configured to generate SST emissions;
a wavelength converter material spaced apart from the SST structure, the wavelength converter material having a thickness, wherein the forward-facing surface and the wavelength converter material are configured such that at least a portion of the SST emissions that exit the SST assembly at the front side do not pass completely through the thickness of the wavelength converter material, wherein the thickness of the wavelength converter material is such that more SST emissions reflect from an outer surface of the wavelength converter material than pass through the wavelength converter material; and
wherein the wavelength converter material is on the reflective material of the forward-facing surface.
9. The SST assembly of claim 1 wherein the wavelength converter material comprises a phosphorous material.
10. A solid state transducer (SST) assembly having a front side from which emissions exit the SST assembly and a back side opposite the front side, the SST assembly comprising:
a support substrate having a surface generally facing the front side of the SST assembly;
a wavelength converter material on the surface and configured to produce converter emissions, wherein the converter material has a thickness; and
at least one SST structure carried by the support substrate and separated from the wavelength converter material, the at least one SST structure being configured to generate SST emissions, wherein at least a portion of the SST emissions are directed generally toward the wavelength converter material and pass through less than the complete thickness of the wavelength converter material before exiting the SST assembly, wherein the thickness of the wavelength converter material is configured such that more of the SST emissions reflect off of a forward-facing surface of the wavelength converter material and exit the SST assembly without passing through wavelength converter material than pass completely through the wavelength converter material, and wherein the wavelength converter material and the surface of the support substrate are configured to reflect SST and converter emissions toward the front side of the SST assembly.
11. The SST assembly of claim 10 wherein at least a portion of the SST emissions strike the wavelength converter material traveling in a direction substantially opposite of the direction in which the emissions exit the SST assembly.
12. The SST assembly of claim 10 wherein:
the at least one SST structure faces generally toward the back side of the SST assembly; and
the wavelength converter material is positioned toward the back side of the SST assembly with respect to the SST structures.
13. The SST assembly of claim 10 wherein the surface is reflective, and wherein the wavelength converter material is conformal to the surface.
14. The SST assembly of claim 11 wherein the surface and the wavelength converter material are angled and/or curved toward the front side of the SST assembly.
15. The SST assembly of claim 10 wherein the surface and the wavelength converter material are configured such that the SST emissions strike the wavelength converter material before exiting the SST assembly.
16. The SST assembly of claim 10 , further comprising a cover feature over the at least one SST structure, wherein the cover feature is configured to direct the SST emissions generally toward the wavelength converter material before the SST emissions exit the SST assembly.
17. The SST assembly of claim 10 wherein the wavelength converter material has an outer surface, and wherein at least a portion of the SST emissions reflect once from the outer surface before exiting the SST assembly.
18. A lighting system comprising:
a solid-state transducer (SST) assembly having a front side and a back side opposite the front side, the SST assembly comprising—
a support substrate having a forward-facing surface and an opening from which emissions exit the SST assembly, the opening being at the front side;
an SST structure carried by the support substrate and configured to generate light; and
a converter material spaced apart from the SST structure on the forward-facing surface, the converter material having a thickness, wherein the forward-facing surface and the converter material are configured such that at least a portion of the light that exits the SST assembly at the front side does not pass completely through the thickness of the converter material, wherein the thickness of the wavelength converter material is such that more light reflects off an outer surface of the wavelength converter material than passes through the wavelength converter material, and wherein the converter material is configured to change the wavelength of the light emitted by the SST structure; and
a driver operably coupled to the SST assembly.
19. The lighting system of claim 18 wherein the light emitted by the SST structure initially travels generally toward the back side of the SST assembly before being reflected toward the front side by the converter material and/or the forward-facing surface.
20. The lighting system of claim 18 wherein:
the forward-facing surface comprises a reflective material; and
the converter material is on at least a portion of the reflective material.
21. The lighting system of claim 18 wherein:
the SST structure faces generally toward the front side of the SST assembly; and
the forward-facing surface and the converter material are spaced laterally outward from the SST structure and is angled and/or curved toward the front side.
22. The lighting system of claim 18 wherein the SST assembly further includes a cover feature on the SST structure, the cover feature being configured to direct at least a portion of the light emitted by the SST structure generally toward the forward-facing surface.
23. A light emitting diode (LED) assembly having a front side from which light exits the LED assembly and a back side opposite the front side, the LED assembly comprising:
a support substrate having a forward-facing surface generally facing the front side of the LED assembly;
a wavelength converter material on the forward-facing surface of the support substrate and having a thickness;
an LED structure carried by the support substrate and spaced apart from the wavelength converter material, the LED structure being configured to generate light directed generally toward the wavelength converter material,
wherein at least a portion of the light that exits the LED assembly at the front side does not pass completely through the thickness of the wavelength converter material, and
wherein the thickness of the wavelength converter material is such that more light reflects off of an outer surface of the wavelength converter material than passes through the wavelength converter material.
24. The LED assembly of claim 23 wherein:
the forward-facing surface includes a reflective material; and
the wavelength converter material is on the reflective material at the forward-facing surface.
25. The LED assembly of claim 23 wherein:
the LED structure faces generally toward the back side of the LED assembly;
the forward-facing surface is positioned toward the back side of the LED assembly relative to the LED structure; and
the LED assembly is configured such that the light from the LED structure initially travels generally toward the back side of the LED assembly where the light strikes an outer surface of the wavelength converter material and reflects toward the front side to exit the LED assembly.
26. The LED assembly of claim 23 wherein:
the LED structure faces generally toward the front side of the LED assembly
the forward-facing surface is spaced laterally outward from the LED structure; and
the LED assembly further includes a cover feature on the LED structure, the cover feature being configured to direct at least a portion of the light from the LED structure generally toward the forward-facing surface.
27. The LED assembly of claim 23 , further comprising a cover feature on the LED structure, the cover feature being shaped to direct light from the LED structure generally toward the forward-facing surface.