High color gamut photoluminescence wavelength converted white light emitting devices
A white light emitting device (backlight) comprises: a Multiple Quantum Well (MQW) dual-wavelength LED; and a narrowband photoluminescence material that generates red light with a peak emission wavelength from about 620 nm to about 660 nm. The MQW dual-wavelength LED comprises at least one first Quantum Well (QW) that generates blue light with a dominant wavelength from 440 nm to 470 nm and at least one second Quantum Well (QW) to generate green light with a dominant wavelength from 520 nm to 540 nm.
1. A light emitting device comprising:
a dual-wavelength Light Emitting Diode (LED) chip; and
a manganese-activated fluoride phosphor comprising at least one of: K 2 SiF 6 :Mn 4+ , K 2 TiF 6 :Mn 4+ and K 2 GeF 6 :Mn 4+ for generating light with a peak emission wavelength from 620 nm to 660 nm; and
wherein the dual-wavelength LED chip comprises a first p-n junction diode comprising a first Multiple Quantum Well structure for generating a first light with a dominant wavelength from 440 nm to 470 nm and a full width at half maximum emission intensity from 15 nm to 25 nm and a second p-n junction diode comprising a second Multiple Quantum Well structure for generating a second light with a dominant wavelength from 520 nm to 540 nm and a full width at half maximum emission intensity from 15 nm to 25 nm.
2. The light emitting device of claim 1 , wherein the manganese-activated fluoride phosphor is disposed on the dual-wavelength LED chip.
3. The light emitting device of claim 1 , wherein the manganese-activated fluoride phosphor comprises a layer located remotely to the dual-wavelength LED chip.
4. The light emitting device of claim 1 , wherein the device is for generating light with a spectrum having a color gamut which is at least one of: at least 90% NTSC RGB color space standard, and at least 90% DCI-P3 RGB color space standard.
5. The light emitting device of claim 1 , wherein the first light and the second light comprise a respective peak, and wherein a ratio of a peak emission intensity of the second light to a peak emission intensity of the first light is from 30% to 60%.
6. The light emitting device of claim 1 , wherein each of the first and second p-n junction diodes comprises an InGaN Multiple Quantum Well structure disposed between a p-doped GaN layer and n-doped GaN layer.
7. The light emitting device of claim 6 , wherein the first p-n junction diode comprises a first InGaN Multiple Quantum Well structure disposed between a first p-doped GaN layer and a first n-doped GaN layer, and the second p-n junction diode comprises a second InGaN Multiple Quantum Well structure disposed between a second p-doped GaN layer and a second n-doped GaN layer.
8. The light emitting device of claim 7 , wherein the first and second p-n junction diodes are disposed on top of each other.
9. The light emitting device of claim 6 , wherein the InGaN Multiple Quantum Well structures are disposed between the same p-doped GaN and n-doped GaN layers.
10. The light emitting device of claim 9 , wherein the InGaN Multiple Quantum Well structures are adjacent each other.
11. The light emitting device of claim 9 , wherein the InGaN Multiple Quantum Well structures are disposed on top of each other.
12. The light emitting device of claim 9 , wherein the InGaN Multiple Quantum Well structures are integrated as a single structure.
13. The light emitting device of claim 1 , wherein the light emitting device comprises a display backlight.