ROHS compliant mixed quantum dot films
ROSH compliant mixed quantum dot films are disclosed which, when contained in a film within a display, exhibit high color gamut, high energy efficiency, and a narrow full width at half maximum at individual wavelength emissions.
1 . An optical film useful in a display device comprising a first population of cadmium-containing core-shell nanostructures and a second population of core-shell nanostructures that are not cadmium-containing core-shell nanostructures in a common matrix material; wherein a peak emission wavelength of the first population is within ±10 nanometers of the peak emission wavelength of the second population, and further comprising a third population of nanostructures with a different peak emission wavelength.
2 . The optical film of claim 1 , wherein the optical film comprises 10 to 99 ppm of cadmium.
3 . The optical film of claim 1 , wherein the second population of nanostructures has a core selected from the group consisting of ZnO, ZnSe, ZnS, ZnTe, HgO, HgSe, HgS, HgTe, BN, BP, BAs, AlN, AIP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, perovskite, and Culn x Ga 1-x SySe 2-y .
4 . The optical film of claim 1 , wherein the first population of core-shell nanostructures are CdSe/ZnSe/ZnS and the second population of core-shell nanostructures are InP/ZnSe/ZnS.
5 . The optical film of claim 1 , wherein the emission spectra of each of the first, second, and third populations of core-shell nanostructures has a full width at half maximum of 10 to 50 nanometers.
6 . The optical film of claim 1 , wherein the optical film is capable of achieving a Rec.2020 coverage of greater than 90% in a display device.
7 . The optical film of claim 1 , comprising a first population of cadmium-containing core-shell nanostructures with a full width at half maximum of 20 to 40 nanometers, and a quantum yield of greater than about 90%.
8 . The optical film of claim 1 , comprising a second population of non-cadmium-containing core-shell nanostructures with a full width at half maximum of 20 to 45 nanometers, and a quantum yield of greater than about-75%.
9 . The optical film of claim 1 , wherein the peak emission wavelengths of the first and second populations are the same.
10 . The optical film of claim 1 , wherein the third population of nanostructures are either CdSe or InP nanostructures.
11 . The optical film of claim 1 , wherein the peak emission wavelengths of the first and second population of nanostructures are at 539 nm, and the peak emission wavelength of the third population of nanostructures is at 639 nm.
12 . The optical film of claim 1 , wherein the peak emission wavelengths of the first and second population of nanostructures are at 639 nm, and the peak emission wavelength of the third population of nanostructures is at 539 nm.
13 . The optical film of claim 1 , wherein the matrix material comprises of thiol-functionalized or polythiol-functionalized polymers.
14 . The optical film of claim 1 , wherein the nanostructures further comprise a ligand bound thereto.
15 . A display device, comprising the optical film of claim 1 .
16 . The display device of claim 15 , having a Rec.2020 coverage of 90 to 98%.
17 . The display device of claim 15 , comprising:
a layer that emits radiation;
the optical film layer disposed on the radiation emitting layer;
an optically transparent barrier layer on the film layer; and
an optical element, disposed on the barrier layer.
18 . The display device of claim 17 , wherein the radiation emitting layer, the film layer, and the optical element are part of a pixel unit of the display device.
19 . The display device of claim 17 , wherein the optical element is a color filter.
20 . The display device of claim 17 , wherein the optically transparent barrier layer is configured to protect the nanostructures from degradation by light flux, heat, oxygen, moisture, or a combination thereof.