Light emitting device grown on wavelength converting substrate
View Patent ↗In some embodiments of the invention, a device includes a substrate and a semiconductor structure. The substrate includes a wavelength converting element comprising a wavelength converting material disposed in a transparent material, a seed layer comprising a material on which III-nitride material will nucleate, and a bonding layer disposed between the wavelength converting element and the seed layer. The semiconductor structure includes a III-nitride light emitting layer disposed between an n-type region and a p-type region, and is grown on the seed layer.
1. A device comprising:
a substrate comprising:
a wavelength converting element comprising a wavelength converting material disposed in a transparent material;
a seed layer comprising a material on which III-nitride material nucleates; and
a bonding layer disposed between the wavelength converting element and the seed layer; and
a semiconductor structure grown on the seed layer, the semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region.
2. The device of claim 1 wherein a luminescent property of the wavelength converting element is reduced less than 20% when the wavelength converting element is exposed to a temperature greater than 800° C. for at least two hours.
3. The device of claim 1 wherein the wavelength converting material is phosphor and the transparent material is one of glass, quartz, and SiO 2 .
4. The device of claim 1 wherein:
the wavelength converting material is disposed in a first portion of the transparent material; and
a second portion of the transparent material is without wavelength converting material.
5. The device of claim 1 wherein the wavelength converting element comprises a wavelength converting material disposed in a transparent material, bonded to a ceramic phosphor.
6. A device comprising:
a substrate comprising:
a wavelength converting element;
a seed layer comprising a material on which III-nitride material nucleates; and
a dichroic filter disposed between the wavelength converting element and the seed layer; and
a semiconductor structure grown on the seed layer, the semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region.
7. The device of claim 6 wherein the dichroic filter is configured to reflect light of a wavelength emitted by the wavelength converting element.
8. The device of claim 6 wherein the wavelength converting element comprises a ceramic phosphor.
9. The device of claim 6 wherein the wavelength converting element comprises a wavelength converting material disposed in a transparent material.
10. The device of claim 6 further comprising a bonding layer disposed between the dichroic filter and the seed layer.
11. A device comprising:
a substrate comprising:
a wavelength converting element;
a seed layer comprising a material on which III-nitride material nucleates; and
a bonding layer disposed between the wavelength converting element and the seed layer;
a semiconductor structure grown on the seed layer, the semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region; and
a scattering structure configured to scatter light emitted by at least one of the III-nitride light emitting layer and the wavelength converting element.
12. The device of claim 11 wherein the scattering structure comprises a III-nitride layer with a rough surface.
13. The device of claim 12 further comprising a transparent conductive layer disposed between the rough surface and a metal contact.
14. The device of claim 12 further comprising:
a transparent insulating layer disposed between the rough surface and a metal contact, wherein the transparent insulating layer has a planar top surface; and
at least one opening formed in the transparent insulating layer, wherein conductive material is disposed in the opening.
15. The device of claim 11 wherein the scattering structure comprises a periodic variation in index of refraction, wherein the variation is in a direction parallel to a major surface of the light emitting layer.
16. The device of claim 15 wherein the periodic variation in index of refraction is disposed within the n-type region.
17. The device of claim 15 wherein the periodic variation in index of refraction is disposed between the n-type region and the seed layer.
18. The device of claim 11 wherein the wavelength converting element comprises a phosphor capable of emitting red light.
19. The device of claim 18 wherein:
the wavelength converting element is a first wavelength converting element, the device further comprising a second wavelength converting element comprising a phosphor capable of emitting green or yellow light; and
the first wavelength converting element is disposed between the semiconductor structure and the second wavelength converting element.