Methods for synthesis of inorganic nanostructures using molten salt chemistry
The invention relates to highly luminescent nanostructures with strong blue light absorbance, particularly core/shell nanostructures comprising an In (1-x) Ga x P core and ZnSe and/or ZnS shell layers, wherein 0<x<1. The invention also relates to methods of producing such nanostructures.
1. A nanostructure comprising:
a core, the core comprising In (1-x) Ga x P, wherein 0<x<1; and
at least one shell disposed on the core, the at least one shell comprising ZnSe;
wherein the optical density at 450 nm per total mass (OD 450 /total mass) of the nanostructure is between about 0.3 and about 1.0.
2. The nanostructure of claim 1 , wherein the nanostructure comprises a first shell comprising ZnSe and a second shell.
3. The nanostructure of claim 2 , wherein the second shell comprises ZnS.
4. The nanostructure of claim 1 , wherein the diameter of the core is between about 3 nm and about 10 nm.
5. The nanostructure of claim 1 , wherein the diameter of the core is about 5 nm.
6. The nanostructure of claim 2 , wherein the thickness of the first shell is between about 0.5 nm and about 4 nm.
7. The nanostructure of claim 2 , wherein the thickness of the second shell is between about 0.5 nm and about 3 nm.
8. The nanostructure of claim 1 , wherein the OD 450 /total mass of the nanostructure is between about 0.5 and about 0.7.
9. The nanostructure of claim 1 , wherein the wavelength of maximum absorbance of the nanostructure is between about 430 nm and about 490 nm.
10. The nanostructure of claim 1 , wherein the nanostructure is a quantum dot.
11. The nanostructure of claim 1 , wherein the nanostructure is free of cadmium.
12. A device comprising the nanostructure of claim 1 .
13. The device of claim 12 , wherein the device is a display device that comprises a quantum dot color converter comprising:
a back plane;
a display panel disposed on the back plane; and
a quantum dot layer comprising the nanostructure, the quantum dot layer disposed on the display panel.
14. The device of claim 13 , wherein the quantum dot layer comprises a patterned quantum dot layer.
15. The device of claim 13 , wherein the backplane comprises a blue LED, an LCD, an OLED, or a microLED.
16. The device of claim 13 , wherein the display device does not comprise a blue light filter.
17. The device of claim 16 , wherein the blue light filter has a transmittance smaller than 15% for light with a wavelength below about 510 nm.
18. A method of making In (1-x) Ga x P nanostructures, wherein 0<x<1, comprising:
(a) admixing InP nanostructures comprising at least one sulfur-containing ligand and a halide salt mixture at a temperature between about 250° C. and 450° C. to form a molten mixture;
(b) admixing the molten mixture obtained in (a) with a gallium source at a temperature between about 290° C. and 380° C.;
to provide the In (1-x) Ga x P nanostructures.
19. The method of claim 18 , wherein admixing the solid in (b) and the halide salt mixture further comprises grinding the solid in (b) and the halide salt mixture prior to the heating.
20. A method of making a In (1-x) Ga x P/ZnSe/ZnS core/shell/shell nanostructures, comprising:
(a) providing a core comprising In (1-x) Ga x P nanostructures;
(b) admixing the In (1-x) Ga x P nanostructures in (a) with a first zinc source and a selenium source; and
(c) admixing the admixture in (b) with a second zinc source and a sulfur source to provide the In (1-x) Ga x P/ZnSe/ZnS core/shell/shell nanostructures;
wherein 0<x<1; and wherein the optical density at 450 nm per total mass (OD 450 /total mass) of the nanostructure is between about 0.3 and about 1.0.