Films comprising bright silver based quaternary nanostructures
Disclosed are films comprising Ag In, Ga, and S (AIGS) nanostructures and at least one ligand bound to the nanostructures. In some embodiment, the AIGS nanostructures have a photon conversion efficiency of greater than 32% and a peak wavelength emission of 480-545 nm when excited using a blue light source with a wavelength of about 450 nm.
1. Nanostructures comprising:
Ag, In, Ga, and S (AIGS); and
at least one ligand,
wherein the nanostructures comprise a gradient of more gallium at a surface of the nanostructures to less gallium in a center of the nanostructures;
wherein the nanostructures have a peak emission wavelength (PWL) between 480 and 545 nm;
wherein the nanostructures have an emission spectrum with a full width half maximum (FWHM) of less than 40 nm; and
wherein the nanostructures have an emission quantum yield (QY) of 80 to 99.9%.
2. The nanostructures of claim 1 , wherein the nanostructures have an OD 450 /mass (mL mg −1 ) greater than or equal to 0.8 mL·mg −1 ·cm −1 .
3. The nanostructures of claim 1 , wherein an average diameter of the nanostructures is less than 10 nm by transmission electron microscopy.
4. The nanostructures of claim 1 , wherein at least 80% of an emission from the nanostructures is band-edge emission.
5. The nanostructures of claim 1 , wherein a molar ratio of In to a total amount of In and Ga in the nanostructures is 0.12 to 0.24.
6. The nanostructures of claim 1 , wherein the nanostructures do not have differentiated shell structures.
7. The nanostructures of claim 1 , wherein the at least one ligand is a polyamino ligand.
8. The nanostructures of claim 7 , wherein the at least one polyamino ligand is a polyamino alkane, a polyamino-cycloalkane, a polyamino heterocyclic compound, a polyamino functionalized silicone, or a polyamino-substituted ethylene glycol.
9. The nanostructures of claim 7 , wherein the polyamino ligand comprises a C 2-20 alkane or C 2-20 cycloalkane substituted by two or three amino groups.
10. The nanostructures of claim 7 , wherein the polyamino ligand is 1,3-cyclohexanebis(methylamine), 2,2-dimethyl-1,3-propanediamine, tris(2-aminoethyl)amine, or 2-methyl-1-diaminopentane.
11. The nanostructures of claim 1 , wherein the at least one ligand is a compound of Formula I,
wherein x is 1 to 100, y is 0 to 100, and R 2 is a C 1-20 alkyl.
12. The nanostructures of claim 1 , wherein the at least one ligand is (3-aminopropyl)trimethoxysilane); (3-mercaptopropyl)triethoxysilane; DL-α-lipoic acid; 3,6-dioxa-1,8-octanedithiol; 6-mercapto-1-hexanol; methoxypolyethylene glycol amine; poly(ethyleneglycol) methyl ether thiol; diethyl phenylphosphonite; dibenzyl N,N-diisopropylphosphoramidite; di-tert-butyl N,N-diisopropylphosphoramidite; tris(2-carboxyethyl)phosphine hydrochloride; poly(ethylene glycol) methyl ether thiol; methoxypolyethylene glycol amine; acrylamide; or polyethylenimine.
13. The nanostructures of claim 1 , wherein the at least one ligand is a combination of aminopolyalkylene oxide and methoxypolyethylene glycol amine; amino-polyalkylene oxide and 6-mercapto-1-hexanol; aminopolyalkylene oxide and (3-mercaptopropyl)triethoxysilane; and 6-mercapto-1-hexanol and methoxypolyethylene glycol amine.
14. A method of preparing the nanostructures of claim 1 , the method comprising:
(a) preparing a mixture comprising AIGS cores, a gallium salt and a ligand in a solvent;
(b) maintaining the mixture to give ion-exchanged nanostructures with a gradient of gallium from a surface to a center of the nanostructures; and
(c) isolating the nanostructures.
15. The method of claim 14 , wherein the gallium salt is an oxygen-free Ga salt.
16. The method of claim 14 , wherein the gallium salt is a gallium halide.
17. The method of claim 14 , wherein the ligand is an oxygen-free ligand.