Display devices comprising green-emitting quantum dots and red KSF phosphor
LED devices emitting white light comprise a blue-emitting LED, green-emitting quantum dots (QDs) and red-emitting K 2 SiF 6 :Mn 4+ (KSF) phosphor. A backlight unit (BLU) for a liquid crystal display (LCD) comprises one or more blue-emitting LEDs and a polymer film containing green-emitting QDs and KSF phosphor. The QDs and/or KSF phosphor may be encapsulated in beads that provide protection from oxygen and/or moisture.
1 . A light-emitting device comprising:
a source of electromagnetic radiation in the blue portion of the spectrum;
one or more particles of K 2 SiF 6: Mn 4+ (KSF) phosphor optically coupled to the source of electromagnetic radiation; and
a plurality of quantum dots optically coupled to the source of electromagnetic radiation.
2 . The light-emitting device recited in claim 1 wherein the source of electromagnetic radiation is a blue light emitting diode (LED).
3 . The light-emitting device recited in claim 2 wherein the one or more particles of KSF phosphor are contained within at least one polymer bead.
4 . The light-emitting device recited in claim 2 wherein the quantum dots are contained within at least one polymer bead.
5 . The light-emitting device recited in claim 2 wherein the quantum dots are contained within at least one first type polymer bead and the one or more particles of KSF phosphor are contained within at least one second type polymer bead.
6 . The light-emitting device recited in claim 2 wherein the quantum dots are contained within a plurality of polymer beads, each polymer bead comprising one or more particles of KSF phosphor and a plurality of quantum dots.
7 . The light-emitting device recited in claim 6 wherein the beads comprise a polymer selected from the group consisting of acrylates, silicones, and epoxies.
8 . The light-emitting device recited in claim 2 wherein the quantum dots are green-emitting quantum dots.
9 . The light-emitting device recited in claim 2 wherein the quantum dots are heavy-metal-free quantum dots.
10 . The light-emitting device recited in claim 4 wherein the LED is housed in a cup-type package and the KSF phosphor is in a polymer matrix and the KSF phosphor in the polymer matrix and the at least one polymer bead with quantum dots are contained within the cup.
11 . The light-emitting device recited in claim 2 wherein the LED is housed in a cup-type package, the KSF phosphor is contained within the cup, and the plurality of quantum dots are in a film remote from the LED package.
12 . The light-emitting device recited in claim 5 wherein the LED is housed in a cup-type package, and the one first type polymer bead and one second type polymer bead are contained in a matrix in the cup of the LED package.
13 . The light-emitting device recited in claim 6 wherein the LED is housed in a cup-type package, and the polymer beads comprising one or more particles of KSF phosphor and a plurality of quantum dots are contained in the cup of the LED package.
14 . The light-emitting device recited in claim 3 wherein the LED is housed in a cup-type package, and the polymer beads comprising one or more particles of KSF phosphor are contained in the cup of the LED package and the plurality of quantum dots are in a film remote from the LED package.
15 . The light-emitting device recited in claim 5 wherein the quantum dots are contained within the at least one first type polymer bead and the one or more particles of KSF phosphor contained within at least one second type polymer bead are in a film remote from the LED.
16 . The light-emitting device recited in claim 6 wherein the plurality of polymer beads comprising one or more particles of KSF phosphor and a plurality of quantum dots are in a film remote from the LED.
17 . The light-emitting device recited in claim 2 wherein the one or more particles of KSF phosphor and the plurality of quantum dots are both contained in a film remote from the LED.
18 . A bead comprising an optically-transparent resin and a plurality of KSF phosphor particles embedded in the resin.
19 . The bead recited in claim 18 further comprising:
a plurality of quantum dots embedded in the resin.
20 . A bead comprising a central core portion surrounded by a shell portion comprising an optically-transparent resin and a plurality of KSF phosphor particles embedded in the shell portion resin.
21 . The bead recited in claim 20 further comprising a plurality of quantum dots in the core portion.
22 . A bead comprising a central core portion comprising an optically-transparent resin surrounded by a shell portion and a plurality of KSF phosphor particles embedded in the core portion resin.
23 . The bead recited in claim 22 further comprising a plurality of quantum dots in the shell portion.
24 . A method for generating white light comprising:
providing a source of electromagnetic radiation in the blue portion of the spectrum;
providing one or more particles of K 2 SiF 6: Mn 4+ (KSF) phosphor optically coupled to the source of electromagnetic radiation; and
providing a plurality of green-emitting quantum dots optically coupled to the source of electromagnetic radiation.
25 . The method recited in claim 24 wherein the source of electromagnetic radiation is a blue light-emitting diode (LED).
26 . A backlight unit for a liquid crystal display comprising:
a source of electromagnetic radiation in the blue portion of the spectrum;
a polymer film optically coupled to the source of electromagnetic radiation and containing one or more particles of K 2 SiF 6: Mn 4+ (KSF) phosphor and a plurality of quantum dots.
27 . The backlight unit recited in claim 26 wherein the source of electromagnetic radiation is a blue light emitting diode (LED).
28 . The backlight unit recited in claim 26 wherein the one or more particles of KSF phosphor are contained within at least one polymer bead.
29 . The backlight unit recited in claim 26 wherein the quantum dots are contained within at least one polymer bead.
30 . The backlight unit recited in claim 26 wherein the quantum dots are contained within at least one first type polymer bead and the one or more particles of KSF phosphor are contained within at least one second type polymer bead.
31 . The backlight unit recited in claim 26 wherein the quantum dots are contained within a plurality of polymer beads, each polymer bead comprising one or more particles of KSF phosphor and a plurality of quantum dots.
32 . The backlight unit recited in claim 31 wherein the beads comprise a polymer selected from the group consisting of acrylates, silicones, and epoxies.
33 . The backlight unit recited in claim 26 wherein the quantum dots are green-emitting quantum dots.
34 . The backlight unit recited in claim 26 wherein the quantum dots are heavy-metal-free quantum dots.