System and method for selected pump LEDs with multiple phosphors
An LED pump light with multiple phosphors is described. LEDs emitting radiation at violet and/or ultraviolet wavelengths are used to pump phosphor materials that emit other colors. The LEDs operating in different wavelength ranges are arranged to reduce light re-absorption and improve light output efficiency.
1. A light source for emitting emitted light, said light source comprising:
a plurality of light emitting diodes for emitting LED light, and comprising at least one first LED having a first peak wavelength in a range 405-430 nm, and at least one second LED having a second peak wavelength which is longer than the first peak wavelength; and
one or more wavelength-converting materials for converting a portion of said LED light into converted light, wherein said emitted light is a combination of unconverted light of said LED light and said converted light, wherein at least one of said one or more wavelength-converting materials is a combination of phosphor and quantum dots.
2. The light source of claim 1 , wherein said at least one second LED is a blue LED.
3. The light source of claim 1 , wherein said at least one of said one or more wavelength-converting materials emits red light.
4. The light source of claim 1 , wherein said at least one of said one or more wavelength-converting materials absorbs a portion of LED light being emitted by said at least one first LED.
5. The light source of claim 1 , said at least one of said one or more wavelength-converting materials is disposed over said at least one first LED.
6. The light source of claim 1 , wherein said one or more wavelength-converting materials comprise a green phosphor and a red phosphor.
7. The light source of claim 1 , wherein said one or more wavelength-converting materials do not include a blue phosphor.
8. The light source of claim 1 , wherein said at least one first LED is characterized by an internal quantum efficiency of at least 70% when operated at a current density of 100 A·cm−2.
9. The light source of claim 1 , wherein said emitted light is white light.