Thin film light emitting diode
View Patent ↗Light emitting LEDs devices comprised of LED chips that emit light at a first wavelength, and a thin film layer over the LED chip that changes the color of the emitted light. For example, a blue LED chip can be used to produce white light. The thin film layer beneficially consists of a florescent material, such as a phosphor, and/or includes tin. The thin film layer is beneficially deposited using chemical vapor deposition.
1. A light emitting diode (LED), comprising:
an LED chip having a first electrical contact and a second electrical contact, the LED chip emitting blue light having a first wavelength in response to applied electrical power; and
a thin film layer over the LED chips;
a passivation layer between the thin film layer and the LED chip, wherein the thin film layer is prevented from directly contacting the LED chip;
wherein the thin film layer and the blue light interact to form light having a second wavelength.
2. An LED according to claim 1 , wherein the thin film layer includes at least one of phosphor and tin.
3. An LED according to claim 1 , further comprising a second passivation layer over the thin film layer.
4. An LED according to claim 1 , wherein the thin film layer and the blue light interact to form white light.
5. An LED according to claim 1 , further comprising a first bonding wire connected to the first electrical contact and a second bonding wire connected to the second electrical contact.
6. An LED according to claim 1 , wherein the LED chip has a lateral topology structure.
7. An LED according to claim 6 , wherein the LED chip includes:
a substrate;
an n-type GaN structure on a surface of the substrate;
an active layer having at least one quantum well on the n-GaN structure;
a p-type GaN layer on the active layer;
a transparent conductive layer on the p-type GaN layer;
a p-type electrical contact on the transparent conductive layer; and
an n-type electrical contact on the n-type G 3 aN structure.
8. An LED according to claim 7 , wherein the p-type electrical contact forms the first electrical contact and the n-type electrical contact forms the second electrical contact.
9. An LED according to claim 7 , wherein the n-type GaN structure includes an n-type GaN buffer layer.
10. An LED according to claim 7 , wherein the substrate includes sapphire.
11. An LED according to claim 1 , wherein the LED chip has a vertical topology structure.
12. An LED according to claim 11 , wherein the LED chip includes:
an n-type GaN structure;
an n-type electrical contact adjacent a surface of the n-type GaN structure;
an active layer having at least one quantum well on the n-type GaN structure;
a p-type GaN layer on the active layer;
a transparent conductive layer on the p-type GaN layer; and
a p-type electrical contact on the transparent conductive layer.
13. An LED according to claim 12 , wherein the p-type electrical contact forms the first electrical contact and the n-type electrical contact forms the second electrical contact.
14. An LED according to claim 12 , wherein the n-type GaN structure includes an n-type GaN buffer layer.
15. An LED according to claim 1 , wherein the passivation layer includes SiO 2 .
16. An LED according to claim 1 , wherein the passivation layer includes Si x N y .
17. An LED according to claim 1 , further including a package environmentally protecting the LED chip.
18. A light emitting diode (LED), comprising:
an LED chip having a first electrical contact and a second electrical contact, the LED chip emitting light having a first wavelength in response to an applied electrical power; and
a thin film layer over the LED chip, wherein a passivation layer is interposed between the thin film layer and the LED chip;
wherein the thin film layer converts the light of the first wavelength to a light of second wavelength.
19. An LED according to claim 18 , wherein the thin film layer includes a fluorescent material.
20. An LED according to claim 18 , further comprising a second passivation layer over the thin film layer.
21. An LED according to claim 18 , wherein the light of the second wavelength is white light.
22. An LED according to claim 18 , further comprising a first bonding wire connected to the first electrical contact and a second bonding wire connected to the second electrical contact.
23. An LED according to claim 18 , wherein the LED chip has a lateral topology structure.
24. An LED according to claim 18 , wherein the LED chip has a vertical topology structure.