Recipient luminophoric mediums having narrow spectrum luminescent materials and related semiconductor light emitting devices and methods
View Patent ↗Light emitting devices include a light emitting diode (“LED”) and a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED. In some embodiments, the recipient luminophoric medium includes a first broad-spectrum luminescent material and a narrow-spectrum luminescent material. The broad-spectrum luminescent material may down-convert radiation emitted by the LED to radiation having a peak wavelength in the red color range. The narrow-spectrum luminescent material may also down-convert radiation emitted by the LED into the cyan, green or red color range.
1. A light emitting device, comprising:
a light emitting diode (“LED”); and
a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED, the recipient luminophoric medium including at least:
a first broad-spectrum luminescent material that down-converts a first portion of the radiation emitted by the LED to radiation having a peak wavelength in the red color range; and
a first narrow-spectrum luminescent material that down-converts a second portion of the radiation emitted by the LED to radiation having a peak wavelength in the red color range.
2. The light emitting device of claim 1 , the recipient luminophoric medium further comprising a second broad-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in a color range other than the red color range.
3. The light emitting device of claim 2 , further comprising a second narrow-spectrum luminescent material that down-converts a fourth portion of the radiation emitted by the LED to radiation having a peak wavelength in the green or cyan color range.
4. The light emitting device of claim 2 , wherein the radiation emitted by the second broad-spectrum luminescent material has a peak wavelength in the green color range and has a full-width-half-maximum emission bandwidth that extends into the cyan color range.
5. The light emitting device of claim 2 , wherein radiation emitted by the second broad-spectrum luminescent material has a peak wavelength between 525 nm and 550 nm and has a full-width-half-maximum emission bandwidth that extends below 500 nm.
6. The light emitting device of claim 5 , the recipient luminophoric medium further comprising a third broad-spectrum luminescent material that down-converts a fourth portion of the radiation emitted by the LED to a radiation having a peak wavelength between 551 nm and 585 nm.
7. The light emitting device of claim 6 , wherein the first broad-spectrum luminescent material comprises a (Ca 1-x Sr x )SiAlN 3 :Eu 2+ phosphor, the second broad-emission luminescent material comprises a LuAG:Ce phosphor, and the third broad-spectrum luminescent material comprises a YAG:Ce phosphor.
8. The light emitting device of claim 1 , wherein the light emitting device emits a warm white light having a correlated color temperature between about 2500 K and about 4100 K, a CRI value of at least 90 and a Lumen equivalent output of at least 330 Lum/W-Optical.
9. The light emitting device of claim 1 , wherein the recipient luminophoric medium is applied directly onto the LED, and wherein the recipient luminophoric medium includes a binder material that is cured by heat energy in the LED at the time the recipient luminophoric medium is applied to the LED.
10. A light emitting device, comprising:
a light emitting diode (“LED”); and
a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED, the recipient luminophoric medium including at least:
a first broad-spectrum luminescent material that down-converts a first portion of the radiation emitted by the LED to radiation having a peak wavelength in a first color range; and
a first narrow-spectrum luminescent material that down-converts a second portion of the radiation emitted by the LED to radiation having a peak wavelength in the first color range.
11. The light emitting device of claim 10 , wherein the first color range is the red color range.
12. The light emitting device of claim 11 , the recipient luminophoric medium further comprising a second broad-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in the yellow color range.
13. The light emitting device of claim 12 , the recipient luminophoric medium further comprising a third broad-spectrum luminescent material that down-converts a fourth portion of the radiation emitted by the LED to radiation having a peak wavelength in the green color range, and that has a full-width-half-maximum emission bandwidth that extends into the cyan color range.
14. The light emitting device of claim 11 , the recipient luminophoric medium further comprising a second narrow-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in the cyan color range.
15. The light emitting device of claim 11 , wherein the first broad-emission luminescent material comprises a red phosphor having a peak wavelength of less than 620 nm and a full-width-half-maximum emission bandwidth of between about 60 nm and about 80 nm.
16. A light emitting device, comprising:
a light emitting diode (“LED”); and
a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED, the recipient luminophoric medium including at least:
a first broad-spectrum luminescent material that down-converts a first portion of the radiation emitted by the LED to radiation having a peak wavelength in the red color range;
a second broad-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in a color range other than the red color range; and
a first narrow-spectrum luminescent material that down-converts a second portion of the radiation emitted by the LED to radiation having a peak wavelength in the cyan color range.
17. The light emitting device of claim 16 , further comprising a second narrow-spectrum luminescent material that down-converts a fourth portion of the radiation emitted by the LED to radiation having a peak wavelength in the red color range.
18. The light emitting device of claim 16 , wherein the narrow-spectrum luminescent material comprises a quantum dots material.
19. A light emitting device, comprising:
a light emitting diode (“LED”); and
a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED, the recipient luminophoric medium including at least:
a first broad-spectrum luminescent material that down-converts a first portion of the radiation emitted by the LED to radiation having a peak wavelength that is between 610 and 629 nm;
a second broad-spectrum luminescent material that down-converts a second portion of the radiation emitted by the LED to radiation having a peak wavelength below 600 nm; and
a narrow-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in the red color range.
20. The light emitting device of claim 19 , the recipient luminophoric medium further comprising a narrow-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in the green color range or the cyan color range.
21. The light emitting device of claim 19 , wherein the radiation emitted by the second broad-spectrum luminescent material has a peak wavelength in the green color range and has a full-width-half-maximum emission bandwidth that extends into the cyan color range.
22. A packaged light emitting device, comprising:
a light emitting diode (“LED”) that emits light in the blue color range; and
a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED, the recipient luminophoric medium including at least:
a first broad-spectrum luminescent material that down-converts a first portion of the radiation emitted by the LED to radiation having a peak wavelength in a first color range; and
a first narrow-spectrum luminescent material that down-converts a second portion of the radiation emitted by the LED to radiation having a peak wavelength in the blue color range.
23. The packaged light emitting device of claim 22 , further comprising a submount that includes at least one reflective portion, and wherein the recipient luminophoric medium is conformally coated on the LED and on the at least one reflective portion.
24. The packaged light emitting device of claim 23 , wherein the first color range is the yellow color range, and wherein the recipient luminophoric medium further includes a second broad-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in the red color range.
25. The packaged light emitting device of claim 24 , wherein the recipient luminophoric medium further includes a third broad-spectrum luminescent material that down-converts a fourth portion of the radiation emitted by the LED to radiation having a peak wavelength in the green color range that has a full-width-half-maximum emission bandwidth that extends into the cyan color range.
26. The packaged light emitting device of claim 24 , wherein the LED comprises a first blue LED, the packaged light emitting device further comprising a second blue LED mounted on the submount, wherein the recipient luminophoric medium is conformally coated to cover the two blue LEDs and a portion of the submount that between the two blue LEDs.
27. The packaged light emitting device of claim 26 , wherein the two blue LEDs are connected in series.
28. The packaged light emitting device of claim 26 , wherein the two blue LEDs are connected in parallel.
29. The light emitting device of claim 1 , wherein the narrow-spectrum luminescent material comprises a line-emitter luminescent material.
30. The light emitting device of claim 10 , wherein the first narrow-spectrum luminescent material comprises a line-emitter luminescent material.
31. The light emitting device of claim 16 , wherein the first narrow-spectrum luminescent material comprises a line-emitter luminescent material.
32. The light emitting device of claim 1 , wherein the LED comprises a blue LED that emits light in the blue color range, the light emitting device further comprising a second narrow-spectrum luminescent material that down-converts a third portion of the radiation emitted by the LED to radiation having a peak wavelength in the blue color range.
33. The light emitting device of claim 14 , further comprising a third narrow-spectrum luminescent material that down-converts a fourth portion of the radiation emitted by the LED to radiation having a peak wavelength in a color range other than the cyan color range or the red color range.
34. The light emitting device of claim 19 , wherein the LED comprises a blue LED that emits light in the blue color range and the narrow-spectrum luminescent material comprises a first narrow-spectrum luminescent material, further comprising a second narrow-spectrum luminescent material that down-converts a fourth portion of the radiation emitted by the LED to radiation having a peak wavelength in the blue color range.