Film comprising bright silver-based quaternary nanostructures

Abstract

Disclosed are films comprising Ag, In, Ga, and S (AIGS) nanostructures and at least one ligand bound to the nanostructures. In some embodiments, the AIGS nanostructures have a photon conversion efficiency greater than 32% and an emission peak wavelength of 480-545 nm. In some embodiments, the nanostructures have an emission spectrum with a FWHM of 24-38 nm.

Description

Technical Field

[0001] This invention relates to the field of nanotechnology. More specifically, this invention provides a thin, heavy metal-free nanostructured color conversion film that, when excited by a blue light source with a wavelength of approximately 450 nm, exhibits a high photon conversion efficiency (PCE) of greater than 32% at a peak emission wavelength of 480-545 nm. Background Technology

[0002] Effective color conversion is important for lighting and display applications. In display applications, blue light sources with a wavelength of approximately 450nm are most commonly used for backlighting. Most applications require materials free of heavy metals such as Cd and Pb.

[0003] Increased efficiency leads to less power waste and increased emission. Color conversion films are characterized by photon conversion efficiency (PCE), defined as the number of emitted photons divided by the number of source photons. Green, heavy metal-free QD color conversion films used in displays typically have poor performance due to their limited absorption of blue light when excited. Blue absorption is generally inherently limited by the material system used, resulting in the need for much thicker films to absorb sufficient 450nm light.

[0004] Films formed by depositing QD ink are typically cured by UV irradiation. In many cases, this is followed by heat treatment at 180°C for up to 1 hour in the presence of air. The photon conversion efficiency of these films is limited by a combination of poor absorption and poor light conversion due to instabilities throughout these processing steps.

[0005] There remains a need in the field for Ag / In / Ga / S (AIGS) nanostructures with high band edge emission (BE), narrow full width at half maximum (FWHM), high quantum yield (QY), and reduced redshift, which can be used to prepare films with high photon conversion efficiency (PCE) (greater than 32%) at peak emission wavelengths between 480 and 545 nm using an excitation wavelength of approximately 450 nm. Summary of the Invention

[0006] This invention provides a thin, heavy metal-free nanostructured color conversion film that exhibits a high photon conversion efficiency (PCE) greater than 32% at a peak emission wavelength of 480-545 nm when excited using a blue light source with a wavelength of approximately 450 nm. This is achieved by using an Ag / In / Ga / S (AIGS) nanostructure in an ink formulation containing one or more ligands, wherein all ink treatments, subsequent film deposition, processing, and measurements are performed in an oxygen-free environment prior to exposure to blue or ultraviolet light. In some embodiments, the AIGS nanostructure has a focal length emission width (FWHM) of 28-38 nm. In other embodiments, the AIGS nanostructure has an FWHM of less than 32 nm. This narrow FWHM is achieved by adding at least one polyamino ligand to the AIGS nanostructure and preparing the film layer, wherein all treatments of the nanostructured ink, ink deposition, film processing, and measurements are performed in an oxygen-free environment.

[0007] Films formed by depositing QD ink are typically cured by UV irradiation. In many cases, this is followed by heat treatment at 180°C in the presence of air for up to 1 hour. It has been found that photon conversion efficiency decreases due to poor absorption and poor light conversion caused by instabilities throughout these processing steps.

[0008] This document discloses films containing AIGS nanostructures in ink formulations comprising at least one ligand, said films achieving a PCE greater than (>) 32% after heat treatment. In some embodiments, films are provided comprising AIGS nanostructures, at least one ligand, and exhibiting a PCE greater than 32% at peak emission wavelengths of 480-545 nm when excited using a blue light source with a wavelength of 450 nm. The PCE is calculated by integrating the emission spectrum from 484 nm to 700 nm, where the green portion is defined as 484-588 nm. In some embodiments, the film is a thin (5 μm to 15 μm) color conversion film.

[0009] The prepared films exhibit good (>95%) blue light absorption but moderate emission at approximately 450 nm. However, the emission properties of these films are significantly improved when processed in the absence of oxygen and / or light and / or when encapsulated before exposing the films to UV or blue light.

[0010] In some embodiments, the membrane further comprises at least one monomer incorporated into the ligands coated on the AIGS surface. In some embodiments, the at least one monomer is an acrylate (acrylate salt). In some embodiments, the monomer is at least one of the following: ethyl acrylate, hexamethylene diacrylate (HDDA), tetrahydrofurfuryl acrylate, tris(propylene glycol) diacrylate, 1,4-bis(acryloyloxy)butane, or isobornyl acrylate.

[0011] A method for preparing an AIGS membrane is provided, the method comprising:

[0012] (a) Providing an AIGS nanostructure and at least one ligand coated with the nanostructure;

[0013] (b) mixing at least one organic resin with the AIGS nanostructure of (a); and

[0014] (c) A first film comprising a doped AIGS nanostructure, at least one ligand coated with the nanostructure, and at least one organic resin is prepared on the first barrier layer;

[0015] (d) Curing the film by UV irradiation and / or baking;

[0016] (e) Encapsulating the first membrane between the first barrier layer and the second barrier layer; and

[0017] When excited by a blue light source with a wavelength of approximately 450 nm, the encapsulation film exhibits a conversion efficiency (PCE) greater than 32% at a peak emission wavelength of 480-545 nm.

[0018] In some embodiments, the AIGS nanostructure further comprises at least one monomer incorporated into at least one ligand coated on the AIGS surface.

[0019] The following method is also provided, which further includes:

[0020] (f) adding at least one oxygen-reactive material to the mixture of AIGS nanostructures and ligands in (a), adding at least one oxygen-reactive material to the blend in (b), and / or forming a second film comprising at least one oxygen-reactive material on top of the first film prepared in (c); and / or

[0021] (g) A temporary sacrificial barrier layer is formed on the first membrane prepared in (c) to block oxygen and / or water, and the PCE of the membrane is measured, and then the sacrificial barrier layer is removed.

[0022] The following method is also provided, which includes:

[0023] (a) Encapsulating the membrane prior to heat treatment and / or measurement;

[0024] (b) Using oxygen-reactive materials as part of the formulation during heat treatment or light exposure; and / or

[0025] (c) Temporarily block oxygen by using a sacrificial barrier layer.

[0026] In some embodiments, the nanostructure has an emission spectrum with an FWHM of less than 40 nm. In some embodiments, the nanostructure has an emission spectrum with an FWHM of 24-38 nm. In some embodiments, the nanostructure has an emission spectrum with an FWHM of 27-32 nm. In some embodiments, the nanostructure has an emission spectrum with an FWHM of 29-31 nm.

[0027] In some embodiments, the nanostructure has a QY of 80-99.9%. In some embodiments, the nanostructure has a QY of 85-95%. In some embodiments, the nanostructure has a QY of about 86-94%. In some embodiments, the nanostructure has an OD greater than or equal to 0.8. 450 / mass (mL mg) -1 cm -1 ), where OD stands for optical density. In some embodiments, the OD of nanostructures... 450 / mass (mL mg) -1 cm -1 The OD value is within the inclusive range of 0.8-2.5. In some embodiments, the OD value of the nanostructure is... 450 / mass (mL mg) -1 cm -1 The value is in the range of 0.87-1.9, including the endpoints. In some embodiments, the average diameter of the nanostructure is less than 10 nm, as observed by transmission electron microscopy (TEM). In some embodiments, the average diameter is about 5 nm.

[0028] In some embodiments, at least about 80% of the transmissions are edge-triggered. In some embodiments, at least about 90% of the transmissions are edge-triggered. In some embodiments, 92-98% of the transmissions are edge-triggered. In some embodiments, 93-96% of the transmissions are edge-triggered.

[0029] In some implementations, the AIGS nanostructure has a peak emission wavelength (PWL) of approximately 450 nm.

[0030] In some implementations, the AIGS nanostructure includes a gradient of gallium increasing from the surface of the nanostructure to decreasing gallium at the center of the nanostructure.

[0031] In some embodiments, the at least one ligand is an amino ligand, a polyamino ligand, a ligand containing a thiol group, or a ligand containing a silane. Unexpectedly, the use of polyamino ligands has resulted in AIGS-containing films with an FWHM greater than 32 nm.

[0032] In some embodiments, the at least one polyamino ligand is a polyamino alkane, a polyamino-cycloalkane, a polyamino heterocyclic compound, a polyamino-functionalized siloxane, or a polyamino-substituted ethylene glycol. In some embodiments, the polyamino ligand is a C14 compound substituted with two or three amino groups and optionally contains one or two amino groups replacing carbon groups. 2-20 Alkanes or C 2-20 Cycloalkanes. In some embodiments, the polyamino ligand is 1,3-cyclohexanebis(methylamine), 2,2-dimethyl-1,3-propanediamine, or tris(2-aminoethyl)amine.

[0033] In some embodiments, the ligand is a compound of formula I:

[0034]

[0035] in:

[0036] x is between 1 and 100;

[0037] y is between 0 and 100; and

[0038] R 2 It is C 1-20 alkyl.

[0039] In some implementations, x = 19, y = 3, and R 2 =-CH3.

[0040] In some embodiments, 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 glycolamine (approx. mw500); poly(ethylene glycol) methyl ether thiol (approx. mw800); diethyl phenyl phosphite; dibenzyl N,N-diisopropylphosphite; di-tert-butyl N,N-diisopropylphosphite; tris(2-carboxyethyl)phosphine hydrochloride; poly(ethylene glycol) methyl ether thiol (approx. mw2000); methoxypolyethylene glycolamine (approx. mw750); acrylamide; or polyethyleneimine. The mw of the polymer is determined by mass spectrometry.

[0041] In some embodiments, the at least one ligand is a combination of: amino-polyalkylene oxide (about mw1000) and methoxy polyethylene glycolamine (about mw500); amino-polyalkylene oxide (about mw1000) and 6-mercapto-1-hexanol; amino-polyalkylene oxide (about mw1000) and (3-mercaptopropyl)triethoxysilane; and 6-mercapto-1-hexanol and methoxy polyethylene glycolamine (about mw500).

[0042] In some embodiments, the AIGS nanostructure further comprises at least one monomer incorporated into at least one ligand coated on the AIGS surface.

[0043] Also provided are nanostructure compositions comprising:

[0044] (a) AIGS nanostructures exhibiting a PCE greater than 32%, and

[0045] (b) At least one organic resin.

[0046] In some embodiments, the at least one organic resin is cured.

[0047] A method for preparing the nanostructured compositions described herein is also provided, the method comprising:

[0048] (a) Providing an AIGS nanostructure and at least one ligand coated with the nanostructure;

[0049] (b) Blending at least one organic resin with the nanostructure of (a);

[0050] (c) A first film comprising a doped AIGS nanostructure, at least one ligand coated with the nanostructure, and at least one organic resin is prepared on the first barrier layer;

[0051] (d) Curing the film by UV irradiation and / or baking; and

[0052] (e) Encapsulate the first membrane between the first barrier layer and the second barrier layer.

[0053] When excited by a blue light source with a wavelength of approximately 450 nm, the encapsulation film exhibits a conversion efficiency (PCE) greater than 32% at a peak emission wavelength of 480-545 nm.

[0054] In some embodiments, the nanostructure of (a) further comprises at least one monomer incorporated into the ligands coated on the AIGS surface. In some embodiments, the at least one monomer is an acrylate. In some embodiments, the monomer is at least one of the following: ethyl acrylate, HDDA, tetrahydrofurfuryl acrylate, tris(propylene glycol) diacrylate, 1,4-bis(acryloyloxy)butane, or isobornyl acrylate.

[0055] In some embodiments, the method is performed before exposing the encapsulating membrane to air to measure the emission spectrum of the AIGS nanostructure. In some embodiments, the method is performed under an inert atmosphere.

[0056] In some embodiments, the method further includes:

[0057] (f) Add at least one oxygen-reactive material to the mixture of AIGS nanostructures and ligands in (a).

[0058] (g) Add at least one oxygen-reactive material to the blend of (b), and / or

[0059] (h) Forming a second membrane comprising at least one oxygen-reactive material on top of the first membrane prepared in (c); and / or

[0060] (i) A temporary sacrificial barrier layer is formed on the first membrane prepared in (c) to block oxygen and / or water, and the PCE of the membrane is measured, and then the sacrificial barrier layer is removed.

[0061] In some implementations, the two barrier layers exclude oxygen and / or water.

[0062] In some implementations, 92-98% of the launches are edge-fired. In other implementations, 93-96% of the launches are edge-fired.

[0063] A method for preparing the composition is also provided, the method comprising:

[0064] (a) Providing at least one ligand comprising an AIGS nanostructure and coating the surface of the nanostructure; and

[0065] (b) Mix the composition obtained in (a) with at least one second ligand.

[0066] In some embodiments, the composition in (a) further comprises an organic resin. In some embodiments, the composition in (a) further comprises at least one monomer incorporated into the ligands coated on the AIGS surface. In some embodiments, the method further comprises an inkjet printing composition.

[0067] In some embodiments, the method further comprises preparing a membrane comprising the composition obtained in (b). In some embodiments, the method further comprises curing the membrane. In some embodiments, the membrane is cured by heating. In some embodiments, the membrane is cured by exposure to electromagnetic radiation.

[0068] A device containing the aforementioned membrane is also provided.

[0069] Nanostructured molded articles are also provided, the articles comprising:

[0070] (a) First conductive layer;

[0071] (b) the second conductive layer; and

[0072] (c) A film comprising an AIGS nanostructure layer between the first conductive layer and the second conductive layer.

[0073] The nanostructure layer contains AIGS nanostructures with a PCE greater than 32%.

[0074] It also provides a nanostructure color converter, which includes

[0075] Back panel;

[0076] A display panel, wherein the display panel is disposed on the back panel; and

[0077] A film including an AIGS nanostructure layer, the AIGS nanostructure layer comprising AIGS nanostructures with a PCE greater than 32%, the nanostructure layer being disposed on the display panel.

[0078] In some embodiments, the nanostructure layer includes a patterned nanostructure layer. In some embodiments, the backplane includes an LED, LCD, OLED, or microLED.

[0079] Other features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. It should be noted that the invention is not limited to the specific embodiments described herein. These embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to those skilled in the art based on the teachings contained herein. Attached Figure Description

[0080] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the invention and, together with the specification, further serve to explain the principles of the embodiments of the invention and to enable those skilled in the art to implement and use the embodiments of the invention.

[0081] Figure 1 These are photographs of the first and third membranes from left to right. The first and third membranes do not contain polyamino ligands and exhibit extension wrinkling. The second and fourth membranes, which contain polyamino ligands, do not show wrinkling.

[0082] Figure 2A-2C And TEM images showing ion exchange treatment before ( Figure 2A After a single ion exchange treatment ( Figure 2B ) and after two ion exchange treatments ( Figure 2C AIGS nanostructures.

[0083] Figure 3A and 3B It is unsealed ( Figure 3A ) and encapsulation ( Figure 3B A schematic diagram of the membrane.

[0084] Figure 4 It is a scatter plot showing the QY% of a mixture of various ligands.

[0085] Figure 5 It is a scatter plot showing ligand combinations that provide improved QY% (good combinations) and combinations that provide reduced QY% (bad combinations).

[0086] Figure 6 This is a graph showing the QY% of various ligand combinations before ligand exchange (NG), after ligand exchange (LE), and 30 minutes after the thermal test.

[0087] Figure 7 It is a graph showing the QY% of various ligand combinations at various ligand ratios.

[0088] Figure 8 These are two scatter plots showing the PCE of AIGS films with normal baking (PoB) measurements (left) and encapsulation before PCE measurements (right).

[0089] Figure 9 These are two scatter plots showing the PCE of AIGS films baked at 180°C before PCE measurement (left) and with encapsulation (right).

[0090] Figure 10 This is a bar chart showing the photoluminescent quantum yield (PLQY) of AIGS nanostructures undergoing ligand exchange in various solvents at room temperature and 80°C.

[0091] Figure 11 This is a bar chart showing the QY of AIGS nanostructures after ligand exchange in the presence of various monomers.

[0092] Figure 12 This is a line graph showing the extracellular quantum efficiency (EQE) of AIGS nanostructures after ligand exchange, treatment with various monomers, and UV curing.

[0093] Figure 13 This is a bar graph showing the blue light absorption of AIGS nanostructured inks with ligand exchange, treated with various monomers, and spin-coated at 800 rpm.

[0094] Figure 14 This is a line graph showing the effect of diamine ((1,3-bis(aminomethyl)cyclohexane)) on the EQE of the membrane after UV exposure and post-baking at 180°C for 30 minutes (POB).

[0095] Figure 15 It is a line graph showing the effect of the added diamine on viscosity, which is indirectly measured as the blue light absorption in the film after spin coating at 800 RPM.

[0096] Figure 16 This is a bar graph showing the effect of ligand exchange (LE) with diamine (DA) on the QY of the solution. The graph shows that the decrease in QY after heating at 180°C decreases with increasing amount of diamine.

[0097] Figure 17 It is a line graph showing the effect of increased DA content on the PCE of the membrane after UV curing.

[0098] Figure 18 It is a line graph showing the effect of increasing the amount of DA in the membrane on the blue light absorbance of the membrane.

[0099] Figure 19 This is a line graph showing the effect of DA added in the monomer dispersion, in the LE, and in both the monomer dispersion and the LE on the blue light absorbance of the PCE film.

[0100] Figure 20 It is a line graph showing the effect of DA added in the monomer dispersion, in LE, and in both the monomer dispersion and LE on the film viscosity and blue light absorbance.

[0101] Figure 21 It is a line graph showing the effect of various additives on the initial membrane EQE.

[0102] Figure 22 This is a line graph showing the effect of various additives on membrane EQE after POB (Polymerization of Biological Surface)

[0103] Figure 23 It is a line graph showing the effect of the membrane's EQE and blue light absorption with added additives.

[0104] The features and advantages of the invention will become more apparent from the detailed description set forth below when taken in conjunction with the accompanying drawings, in which the same reference numerals consistently identify corresponding elements. In the drawings, the same reference numerals generally indicate the same, functionally similar, and / or structurally similar elements. The first appearance of an element in the drawing is indicated by the leftmost numeral of the corresponding reference numeral. Unless otherwise stated, the drawings provided throughout this disclosure should not be construed as being drawn to scale. Detailed Implementation

[0105] definition

[0106] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The following definitions supplement those in the art and are specific to this application and should not be attributed to any related or unrelated cases, such as any jointly owned patent or application. While any methods and materials similar or equivalent to those described herein may be used in the practice of testing the invention, preferred materials and methods are described herein. Therefore, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0107] Unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” as used in this specification and the appended claims include plural indications. Thus, for example, reference to “a nanostructure” includes a plurality of such nanostructures, and so on.

[0108] As used in this article, the term “about” means that the value of a given quantity has changed by + / - 10% of that value. For example, “about 100 nm” covers a size range of 90 nm to 110 nm (inclusive).

[0109] A "nanostructure" is a structure having at least one region or characteristic dimension with a size less than about 500 nm. In some embodiments, the nanostructure has a dimension less than about 200 nm, less than about 100 nm, less than about 50 nm, less than about 20 nm, or less than about 10 nm. Typically, the region or characteristic dimension is along the smallest axis of the structure. Examples of such structures include nanowires, nanorods, nanotubes, branched nanostructures, nanoquadrupoles, tridrupoles, bidrupoles, nanocrystals, nanodots, quantum dots, nanoparticles, etc. Nanostructures can be, for example, substantially crystalline, substantially single-crystal, polycrystalline, amorphous, or a combination thereof. In some embodiments, each of the three dimensions of the nanostructure has a size less than about 500 nm, less than about 200 nm, less than about 100 nm, less than about 50 nm, less than about 20 nm, or less than about 10 nm.

[0110] When used to refer to nanostructures, the term "heterostructure" refers to a nanostructure characterized by at least two different and / or distinguishable material types. Typically, one region of the nanostructure includes a first material type, while a second region of the nanostructure includes a second material type. In some embodiments, the nanostructure comprises a core of a first material and at least one shell of a second (or third, etc.) material, wherein the different material types are radially distributed around, for example, the long axis of a nanowire, the long axis of an arm of a branched nanowire, or the center of a nanocrystal. The shell may, but does not need to, completely cover the adjacent material for it to be considered a shell or for the nanostructure to be considered a heterostructure; for example, a nanocrystal characterized by a core of one material being covered by islands of a second material is a heterostructure. In other embodiments, the different material types are distributed at different locations within the nanostructure; for example, along the main (long) axis of a nanowire or along the long axis of an arm of a branched nanowire. Different regions within a heterostructure may include entirely different materials, or different regions may include a base material (e.g., silicon) with different dopants or different concentrations of the same dopant.

[0111] As used herein, the “diameter” of a nanostructure refers to the diameter of a cross-section perpendicular to the first axis of the nanostructure, where the first axis has the largest length difference relative to the second and third axes (the second and third axes are the two axes whose lengths are closest to each other). The first axis is not necessarily the longest axis of the nanostructure; for example, for a disk-shaped nanostructure, the cross-section would be a substantially circular cross-section perpendicular to the short longitudinal axis of the disk. In cases where the cross-section is not circular, the diameter is the average of the long and short axes of that cross-section. For elongated or high aspect ratio nanostructures, such as nanowires, the diameter is measured on a cross-section perpendicular to the longest axis of the nanowire. For spherical nanostructures, the diameter is measured from one side to the other through the center of the sphere.

[0112] When used in relation to nanostructures, the terms “crystalline” or “substantially crystalline” refer to the fact that nanostructures typically exhibit long-range order in one or more dimensions of the structure. Those skilled in the art will understand that the term “long-range order” will depend on the absolute size of the particular nanostructure, as the order of a single crystal cannot extend beyond the crystal boundaries. In this case, “long-range order” will mean substantial order over at least a majority of the dimensions of the nanostructure. In some cases, the nanostructure may have an oxide or other coating, or may contain a core and at least one shell. In this case, it should be understood that the oxide, shell, or other coating may, but does not necessarily, exhibit this order (e.g., it may be amorphous, polycrystalline, or otherwise). In this case, the phrases “crystalline,” “substantially crystalline,” “substantially single-crystal,” or “single-crystal” refer to the central core of the nanostructure (excluding the coating or shell). As used herein, the terms “crystalline” or “substantially crystalline” are intended to also cover structures containing various defects, stacking faults, atomic substitutions, etc., as long as the structure exhibits substantial long-range order (e.g., order over at least about 80% of the length of at least one axis of the nanostructure or its core). Furthermore, it will be understood that the interfaces between the core and the exterior of the nanostructure, or between the core and an adjacent shell, or between a shell and a second adjacent shell, can contain amorphous regions, and may even be amorphous. This does not prevent the nanostructure from being crystalline or substantially crystalline as defined herein.

[0113] When used in relation to nanostructures, the term "single-crystal" means that the nanostructure is essentially crystalline and consists essentially of a single crystal. When used for nanostructure heterostructures containing a core and one or more shells, "single-crystal" means that the core is essentially crystalline and consists essentially of a single crystal.

[0114] A "nanocrystal" is a substantially single-crystal nanostructure. Therefore, a nanocrystal has at least one region or characteristic dimension with a dimension less than about 500 nm. In some embodiments, the nanocrystal has dimensions less than about 200 nm, less than about 100 nm, less than about 50 nm, less than about 20 nm, or less than about 10 nm. The term "nanocrystal" is intended to encompass substantially single-crystal nanostructures that include various defects, stacking faults, atomic substitutions, etc., as well as substantially single-crystal nanostructures without such defects, stacking faults, or substitutions. In the case of a nanocrystal heterostructure comprising a core and one or more shells, the core of the nanocrystal is typically substantially single-crystal, but the shell does not necessarily have to be single-crystal. In some embodiments, each of the three dimensions of the nanocrystal has a size less than about 500 nm, less than about 200 nm, less than about 100 nm, less than about 50 nm, less than about 20 nm, or less than about 10 nm.

[0115] The term "quantum dot" (or "dot") refers to a nanocrystal exhibiting quantum confinement or exciton confinement. Quantum dots can be substantially homogeneous in material properties, or in some embodiments, can be heterogeneous, for example, comprising a core and at least one shell. The optical properties of quantum dots can be influenced by their particle size, chemical composition, and / or surface composition, and can be determined by suitable optical tests available in the art. The ability to tailor nanocrystal sizes (e.g., in the range of about 1 nm to about 15 nm) enables photoemission coverage across the entire spectrum, providing great versatility in color rendering.

[0116] The term "oxygen-free ligand" refers to a coordination molecule that does not contain oxygen atoms capable of coordinating or reacting with the metal ions used herein.

[0117] A ligand is a molecule that can interact (weakly or strongly) with one or more surfaces of a nanostructure, for example, through covalent, ionic, van der Waals, or other molecular interactions with the surface of the nanostructure.

[0118] "Photoluminescence quantum yield" (QY) is, for example, the ratio of photons emitted by a nanostructure or a population of nanostructures to the number of photons absorbed. As is known in the art, quantum yield is typically determined by the absolute change in the photon count when a sample is irradiated within an integrating sphere, or by comparison with a standard sample having a well-characterized quantum yield value.

[0119] The peak emission wavelength (PWL) is the wavelength at which the radiation emission spectrum of a light source reaches its maximum value.

[0120] As used herein, the term "full width at half maximum" (FWHM) is a measure of the size distribution of nanostructures. The emission spectra of nanostructures typically have the shape of a Gaussian curve. The width of the Gaussian curve is defined as the FWHM and gives a concept of the particle size distribution. A smaller FWHM corresponds to a narrower size distribution of nanostructured nanocrystals. FWHM also depends on the maximum emission wavelength.

[0121] Compared to corresponding defect emission, band-edge emission is centered at a higher energy (lower wavelength) with a smaller offset from the absorption initiation energy. Furthermore, band-edge emission has a narrower wavelength distribution compared to defect emission. Both band-edge and defect emission follow a normal (approximately Gaussian) wavelength distribution.

[0122] Optical density (OD) is a common method for quantifying the concentration of solutes or nanoparticles. According to Beer-Lambert's law, the absorbance (also known as "extinction") of a particular sample is proportional to the concentration of the solute that absorbs light at a specific wavelength.

[0123] Optical density is the light attenuation per centimeter of material, measured using a standard spectrometer, typically specified as a 1 cm path length. Nanostructured solutions are often measured by their optical density instead of mass or molar concentration because optical density is proportional to concentration, and it is a more convenient way to represent the amount of light absorbed in the nanostructured solution at the wavelength of interest. A nanostructured solution with an OD of 100 is 100 times more concentrated than a product with an OD of 1 (containing 100 times more particles per milliliter).

[0124] Optical density can be measured at any wavelength of interest, such as the wavelength at which the fluorescent nanostructure is selected to excite it. Optical density is the brightness of light as it passes through a solution of a nanostructure at a specific wavelength, and is calculated using the following formula:

[0125] OD = log 10 *(I OUT / I IN )

[0126] in:

[0127] I OUT = The intensity of radiation entering the cell; and

[0128] I IN =Radiation intensity through the pool.

[0129] The optical density of nanostructured solutions can be measured using a UV-VIS spectrometer. Therefore, by using a UV-VIS spectrometer, the optical density can be calculated to determine the amount of nanostructures present in the sample.

[0130] Unless otherwise explicitly stated, the ranges listed in this article include end values.

[0131] This document defines or otherwise characterizes a variety of other terms.

[0132] AIGS nanostructures

[0133] Nanostructures comprising Ag, In, Ga, and S are provided, wherein the nanostructures have a peak emission wavelength (PWL) of 480-545 nm. In some embodiments, at least about 80% of the emission is band-edge emission. The percentage of band-edge emission is calculated by fitting the Gaussian peaks (typically two or more) of the emission spectrum of the nanostructure and comparing the area of ​​the peak with the energy closer to the band gap of the nanostructure (representing band-edge emission) with the sum of the areas of all peaks (band-edge + defect emission).

[0134] In one embodiment, the nanostructure has an FWHM emission spectrum of less than 40 nm. In another embodiment, the nanostructure has an FWHM of 36-38 nm. In some embodiments, the nanostructure has an FWHM emission spectrum of 27-32 nm. In some embodiments, the nanostructure has an FWHM emission spectrum of 29-31 nm.

[0135] In another embodiment, the nanostructure has a QY of about 80% to 99.9%. In another embodiment, the nanostructure has a QY of 85-95%. In another embodiment, the nanostructure has a QY of about 86% and about 94%. In some embodiments, at least 80% of the emission is band-edge emission. In other embodiments, at least 90% of the emission is band-edge emission. In other embodiments, at least 95% of the emission is band-edge emission. In some embodiments, 92-98% of the emission is band-edge emission. In some embodiments, 93-96% of the emission is band-edge emission.

[0136] AIGS nanostructures offer high blue light absorption. As a predicted value for blue light absorption efficiency, the optical density (OD) at 450 nm per mass was calculated as follows: 450 / mass): The optical density of the nanostructured solution was measured in a cuvette with a path length of 1 cm and divided by the dry mass (mg / mL) of the same solution after all volatiles were removed under vacuum (<200 mTorr). In one embodiment, the nanostructures provided herein have an OD of at least 0.8. 450 / mass (mL mg) -1 cm -1 In another embodiment, the nanostructure has an OD of 0.8-2.5. 450 / mass (mL mg) -1 cm -1 In another embodiment, the nanostructure has an OD of 0.87-1.9. 450 / mass (mL mg) -1 cm -1 ).

[0137] In one embodiment, the nanostructure has been treated with gallium ions, causing gallium-indium ion exchange to occur throughout the AIGS nanostructure. In another embodiment, the nanostructure has Ag, In, Ga, and S in its core and is treated by ion exchange with gallium and S ions. In yet another embodiment, the nanostructure has Ag, In, Ga, and S in its core and is treated by ion exchange with silver, gallium, and S ions. In some embodiments, the ion exchange treatment results in a gradient of gallium, silver, and / or sulfur throughout the nanostructure.

[0138] In one embodiment, the average diameter of the nanostructure is less than 10 nm, as measured by TEM. In another embodiment, the average diameter is about 5 nm.

[0139] AIGS nanostructures prepared using GaX3 (X = F, Cl, or Br) precursors and oxygen-free ligands

[0140] Literature reports on AIGS preparation have not attempted to exclude oxygen-containing ligands. When coating AIGS with gallium, oxygen-containing ligands are typically used to stabilize the Ga precursor. Gallium(III) acetylacetonate is commonly used as a precursor that is readily air-processable, while Ga(III) chloride requires careful handling due to its humidity sensitivity. For example, in Kameyama et al., ACS Appl. Mater. Interfaces 10:42844-42855 (2018), gallium(III) acetylacetonate was used as a precursor for both core and core / shell structures. Because gallium has a high affinity for oxygen, oxygen-containing ligands and the use of gallium precursors not prepared under oxygen-free conditions can produce undesirable side reactions, such as gallium oxide, when using Ga and S precursors to generate nanostructures with significant gallium content. These side reactions can lead to defects in the nanostructures and result in lower quantum yields.

[0141] In some embodiments, oxygen-free GaX3 (X = F, Cl, or Br) is used as a precursor to prepare AIGS nanostructures in the preparation of the AIGS core. In some embodiments, GaX3 (X = F, Cl, or Br) is used as both a precursor and an oxygen-free ligand in the preparation of Ga-rich AIGS nanostructures. In some embodiments, GaX3 (X = F, Cl, or Br) is used as both a precursor and an oxygen-free ligand in the preparation of the AIGS core. In some embodiments, GaX3 (X = F, Cl, or Br) is used as both a precursor and an oxygen-free ligand in the preparation of the AIGS core and in the ion exchange treatment of the AIGS core.

[0142] Nanostructures comprising Ag, In, Ga, and S are provided, wherein the nanostructures have a peak emission wavelength (PWL) between 480 and 545 nm, and wherein the nanostructures are prepared using a GaX3 (X = F, Cl, or Br) precursor and an oxygen-free ligand.

[0143] In some embodiments, nanostructures prepared using GaX3 (X = F, Cl, or Br) precursors and anaerobic ligands exhibit FWHM emission spectra of 35 nm or less. In some embodiments, nanostructures prepared using GaX3 (X = F, Cl, or Br) precursors and anaerobic ligands exhibit FWHM of 30-38 nm. In some embodiments, nanostructures prepared using GaX3 (X = F, Cl, or Br) precursors and anaerobic ligands have a QY of at least 75%. In some embodiments, nanostructures prepared using GaX3 (X = F, Cl, or Br) precursors and anaerobic ligands have a QY of 75-90%. In some embodiments, nanostructures prepared using GaX3 (X = F, Cl, or Br) precursors and anaerobic ligands have a QY of approximately 80%.

[0144] The AIGS nanostructures prepared in this paper provide high blue light absorption. In some embodiments, the nanostructures have an OD of at least 0.8. 450 / mass (mL mg) -1 cm -1 In some implementations, the OD of the nanostructure 450 / mass (mL mg) -1 cm -1 The OD is 0.8-2.5. In another embodiment, the nanostructure has an OD of 0.87-1.9. 450 / mass (mL mg) -1 cm -1 ).

[0145] In some embodiments, the nanostructure is treated with gallium ions, causing gallium-to-indium ion exchange to occur throughout the AIGS nanostructure. In some embodiments, the nanostructure contains Ag, In, Ga, and S in its core, with a gallium gradient between the surface and center of the nanostructure. In some embodiments, the nanostructure is an AIGS core treated with AGS, and the core is prepared using a GaX3 (X = F, Cl, or Br) precursor and an oxygen-free ligand. In some embodiments, the nanostructure is an AIGS nanostructure prepared using a GaX3 (X = F, Cl, or Br) precursor and an oxygen-free ligand. In some embodiments, the AIGS nanostructure is prepared by reacting a pre-formed In-Ga reagent with an Ag2S nanostructure, followed by gallium ion exchange via reaction with an oxygen-free Ga salt to form the AIGS nanostructure.

[0146] Methods for preparing AIGS nanostructures

[0147] A method for preparing AIGS nanostructures is provided, the method comprising:

[0148] (a) Preparation of a mixture comprising an AIGS core, a sulfur source, and ligands;

[0149] (b) At a temperature of 180–300 °C, the mixture obtained in (a) is added to a mixture of gallium carboxylate and ligands to obtain an ion-exchanged nanostructure with a gallium gradient from the surface to the center of the nanostructure; and

[0150] (c) Separate the nanostructure.

[0151] In some embodiments, the nanostructure has a pulse wave line (PWL) between 480 and 545 nm, wherein at least about 60% of the emission is band-edge emission.

[0152] A method for preparing AIGS nanostructures is also provided, the method comprising:

[0153] (a) Optionally, Ga(acetylacetonate)3, InCl3, and the ligand are reacted in a solvent at a temperature sufficient to give the In-Ga reagent, and

[0154] (b) React the In-Ga reagent with the Ag2S nanostructure at a temperature sufficient to prepare the AlGS nanostructure.

[0155] (c) Reacting AIGS nanostructures with oxygen-free Ga salts in a solvent containing ligands at a temperature sufficient to obtain ion-exchanged nanostructures with a gallium gradient from the surface to the center of the nanostructures.

[0156] In some embodiments, the nanostructure has a pulse wave line (PWL) between 480 and 545 nm, wherein at least about 60% of the emission is band-edge emission.

[0157] In some embodiments, the ligand is an alkylamine. In some embodiments, the alkylamine ligand is oleylamine. In some embodiments, the ligand is used in excess and acts as a solvent, and the solvent is not present in the reaction. In some embodiments, the solvent is present in the reaction. In some embodiments, the solvent is a high-boiling-point solvent. In some embodiments, the solvent is octadecene, squalane, dibenzyl ether, or xylene. In some embodiments, a sufficient temperature in (a) is 100 to 280°C; a sufficient temperature in (b) is 150 to 260°C; and a sufficient temperature in (c) is 170 to 280°C. In some embodiments, a sufficient temperature in (a) is about 210°C, a sufficient temperature in (b) is about 210°C, and a sufficient temperature in (c) is about 240°C.

[0158] In some embodiments, at least 80% of the transmissions are edge-triggered. In other embodiments, at least 90% of the transmissions are edge-triggered. In other embodiments, at least 95% of the transmissions are edge-triggered. In some embodiments, 92-98% of the transmissions are edge-triggered. In some embodiments, 93-96% of the transmissions are edge-triggered.

[0159] Examples of ligands are disclosed in U.S. Patent Nos. 7,572,395, 8,143,703, 8,425,803, 8,563,133, 8,916,064, 9,005,480, 9,139,770, and 9,169,435, and U.S. Patent Application Publication No. 2008 / 0118755. In one embodiment, the ligand is an alkylamine. In some embodiments, the ligand is an alkylamine selected from dodecylamine, oleylamine, hexadecylamine, dioctylamine, and octadecylamine.

[0160] In some embodiments, the sulfur source in (a) includes: trioctylphosphine sulfide, elemental sulfur, octyl mercaptan, dodecyl mercaptan, octadecyl mercaptan, tributylphosphine sulfide, cyclohexyl isothiocyanate, α-toluene mercaptan, ethylidene trithiocarbonate, allyl mercaptan, bis(trimethylsilyl) sulfide, trioctylphosphine sulfide, or combinations thereof. In some embodiments, the sulfur source in (a) is derived from S8.

[0161] In one implementation, the sulfur source is derived from S8.

[0162] In one embodiment, the temperature in (a) and (b) is approximately 270°C.

[0163] In some embodiments, the mixture in (b) further comprises a solvent. In some embodiments, the solvent is trioctylphosphine, dibenzyl ether, or squalane.

[0164] In some embodiments, gallium carboxylate is C 2-24 Gallium carboxylate. C 2-24 Examples of carboxylates include acetates, propionates, butyrates, valerates, hexanoates, heptanoates, octanoates, nonanoates, decanoates, undecanoates, tridecanoates, tetradecanoates, pentadecanoates, hexadecanoates, octadecanoates (oleates), nonadecanates, and eicosanoates. In one embodiment, gallium carboxylate is gallium oleate.

[0165] In some embodiments, the ratio of gallium carboxylate to AlGS core is 0.008-0.2 mmol gallium carboxylate / mg AlGS. In one embodiment, the ratio of gallium carboxylate to AlGS core is about 0.04 mmol gallium carboxylate / mg AlGS.

[0166] In a further embodiment, the AIGS nanostructures are separated, for example, by precipitation. In some embodiments, the AIGS nanostructures are precipitated by adding a non-solvent for the AIGS nanostructures. In some embodiments, the non-solvent is a toluene / ethanol mixture. The precipitated nanostructures can be further separated by centrifugation and washing with a non-solvent for the nanostructures.

[0167] A method for preparing nanostructures is also provided, the method comprising:

[0168] (a) Preparing a mixture comprising an AlGS core and gallium halide in a solvent, and holding the mixture for a sufficient time to obtain ion-exchanged nanostructures having a gallium gradient from the surface to the center of the nanostructure; and

[0169] (b) Separate the nanostructure.

[0170] In some embodiments, the nanostructure has a pulse wave line (PWL) between 480-545 nm, and at least about 60% of the emission is band-edge emission.

[0171] In some embodiments, at least 80% of the emissions are edge-fired. In other embodiments, at least 90% of the emissions are edge-fired. In still other embodiments, at least 95% of the emissions are edge-fired.

[0172] In some embodiments, gallium halide is gallium chloride, gallium bromide, or gallium iodide. In one embodiment, gallium halide is gallium iodide.

[0173] In some embodiments, the solvent comprises trioctylphosphine. In some embodiments, the solvent comprises toluene.

[0174] In some embodiments, the sufficient time in (a) is 0.1-200 hours. In some embodiments, the sufficient time in (a) is about 20 hours.

[0175] In some embodiments, the mixture is maintained at 20-100°C. In one embodiment, the mixture is maintained at approximately room temperature (20°C to 25°C).

[0176] In some implementations, the molar ratio of gallium halide to AlG cores is from about 0.1 to about 30.

[0177] In a further embodiment, the AIGS nanostructures are separated, for example, by precipitation. In some embodiments, the AIGS nanostructures are precipitated by adding a non-solvent for the AIGS nanostructures. In some embodiments, the non-solvent is a toluene / ethanol mixture. The precipitated nanostructures can be further separated by centrifugation and / or washing with a non-solvent for the nanostructures.

[0178] A method for preparing nanostructures is also provided, the method comprising:

[0179] (a) Preparation of a mixture comprising AIGS nanostructures, a sulfur source and ligands;

[0180] (b) The mixture obtained in (a) was added to a mixture of GaX3 (X = F, Cl, or Br) and oxygen-free ligands at a temperature of 180–300 °C to obtain an ion-exchanged nanostructure with a gallium gradient from the surface to the center of the nanostructure; and

[0181] (d) Separate the nanostructure.

[0182] In some implementations, the nanostructure has a PWL between 480 and 545 nm.

[0183] In some embodiments, the preparation in (a) is carried out under anaerobic conditions. In some embodiments, the preparation in (a) is carried out in a glove box.

[0184] In some embodiments, the addition in (b) is carried out under anaerobic conditions. In some embodiments, the addition in (b) is carried out in a glove box.

[0185] In some embodiments, at least 80% of the emissions are edge-fired. In other embodiments, at least 90% of the emissions are edge-fired. In still other embodiments, at least 95% of the emissions are edge-fired.

[0186] Examples of ligands are disclosed in U.S. Patent Nos. 7,572,395, 8,143,703, 8,425,803, 8,563,133, 8,916,064, 9,005,480, 9,139,770, and 9,169,435, and U.S. Patent Application Publication No. 2008 / 0118755. In some embodiments, the ligand in (a) is an anaerobic ligand. In some embodiments, the ligand in (b) is an anaerobic ligand. In some embodiments, the ligands in (a) and (b) are alkylamines. In some embodiments, the ligand is an alkylamine selected from dodecylamine, oleylamine, hexadecylamine, dioctylamine, and octadecylamine. In some embodiments, the ligand in (a) is oleylamine. In some embodiments, the ligand in (b) is oleylamine. In some embodiments, the ligands in (a) and (b) are oleylamine.

[0187] In one implementation, the sulfur source is derived from S8.

[0188] In one embodiment, the temperature in (a) and (b) is approximately 270°C.

[0189] In some embodiments, the mixture in (b) further comprises a solvent. In some embodiments, the solvent is trioctylphosphine, dibenzyl ether, or squalane.

[0190] In some embodiments, GaX3 is gallium chloride, gallium fluoride, or gallium iodide. In some embodiments, GaX3 is gallium chloride. In some embodiments, GaX3 is Ga(III) chloride.

[0191] In some embodiments, the ratio of GaX3 to AIGS cores is 0.008-0.2 mmol GaX3 / mg AIGS. In some embodiments, the molar ratio of GaX3 to AIGS cores is about 0.1 to about 30. In some embodiments, the ratio of GaX3 to AIGS cores is about 0.04 mmol GaX3 / mg AIGS.

[0192] In some embodiments, AIGS nanostructures are separated, for example, by precipitation. In some embodiments, AIGS nanostructures are precipitated by adding a non-solvent for the AIGS nanostructures. In some embodiments, the non-solvent is a toluene / ethanol mixture. The precipitated nanostructures can be further separated by centrifugation and / or washing with a non-solvent for the nanostructures.

[0193] In some embodiments, the mixture in (a) is maintained at 20°C to 100°C. In some embodiments, the mixture in (a) is maintained at approximately room temperature (20°C to 25°C).

[0194] In some embodiments, the mixture in (b) is maintained at 200°C to 300°C for 0.1 hours to 200 hours. In some embodiments, the mixture in (b) is maintained at 200°C to 300°C for about 20 hours.

[0195] Doped AIGS nanostructures

[0196] In some embodiments, the AIGS nanostructure is doped. In some embodiments, the dopant of the nanocrystal nucleus comprises a metal, including one or more transition metals. In some embodiments, the dopant is a transition metal selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, and combinations thereof. In some embodiments, the dopant comprises a nonmetal. In some embodiments, the dopant is ZnS, ZnSe, ZnTe, CdSe, CdS, CdTe, HgS, HgSe, HgTe, CuInS2, CuInSe2, AlN, AlP, AlAs, GaN, GaP, or GaAs.

[0197] In some embodiments, the nucleus is purified by precipitation from a non-solvent. In some embodiments, the AIGS nanostructure is filtered to remove the precipitate from the nucleus solution.

[0198] Nanostructured Compositions

[0199] In some embodiments, the present invention provides a nanostructure composition comprising:

[0200] (a) at least one AIGS nanostructure group; and

[0201] (b) At least one organic resin.

[0202] In some implementations, the nanostructure has a PWL between 480 and 545 nm.

[0203] In some embodiments, at least 80% of the emission from the nanostructure is band-edge emission. In other embodiments, at least 90% of the emission is band-edge emission. In other embodiments, at least 95% of the emission is band-edge emission. In some embodiments, 92-98% of the emission is band-edge emission. In some embodiments, 93-96% of the emission is band-edge emission.

[0204] In some embodiments, the nanostructure composition further comprises at least one second nanostructure group. Nanostructures with a pulsed light wavelength (PWL) between 480-545 nm emit green light. Additional nanostructure groups emitting in the green, yellow, orange, and / or red regions of the spectrum may be added. These nanostructures have a PWL greater than 545 nm. In some embodiments, the nanostructures have a PWL between 550-750 nm. The size of the nanostructure determines the emission wavelength. The at least one second nanostructure group may comprise group III-V nanocrystals selected from BN, BP, BAs, BSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb. In some embodiments, the core of the second nanostructure group is an InP nanocrystal.

[0205] organic resin

[0206] In some embodiments, the organic resin is a thermosetting resin or an ultraviolet (UV) curable resin. In some embodiments, the organic resin is cured by a method that promotes roller-to-roll processing.

[0207] Thermosetting resins require curing, during which they undergo an irreversible molecular cross-linking process, making the resin infusible. In some embodiments, the thermosetting resin is an epoxy resin, phenolic resin, vinyl resin, melamine resin, urea resin, unsaturated polyester resin, polyurethane resin, allyl resin, acrylic resin, polyamide resin, polyamide-imide resin, phenolic amine condensation resin, urea melamine condensation resin, or a combination thereof.

[0208] In some embodiments, the thermosetting resin is an epoxy resin. Epoxy resins are easy to cure without releasing volatiles or byproducts from a variety of chemicals. Epoxy resins are also compatible with most substrates and tend to easily wet surfaces. See Boyle, MA et al., “Epoxy Resins,” Composites, Vol. 21, ASM Handbook, pp. 78-89 (2001).

[0209] In some embodiments, the organic resin is a silicone thermosetting resin. In some embodiments, the silicone thermosetting resin is OE6630A or OE6630B (Dow Corning Corporation, Auburn, MI).

[0210] In some embodiments, a thermal initiator is used. In some embodiments, the thermal initiator is AIBN [2,2'-azobis(2-methylpropionitrile)] or benzoyl peroxide.

[0211] UV-curable resins are polymers that cure and rapidly harden when exposed to a specific wavelength of light. In some embodiments, the UV-curable resin is a resin having free radical polymerizable groups as functional groups, such as (meth)acryloyloxy groups, ethyleneoxy groups, styryl groups, or vinyl groups; or cationic polymerizable groups, such as epoxy, thioepoxy, ethyleneoxy, or oxetyl groups. In some embodiments, the UV-curable resin is a polyester resin, polyether resin, (meth)acrylic resin, epoxy resin, urethane resin, alkyd resin, spiroacetal resin, polybutadiene resin, or polythiolpolyene resin.

[0212] In some embodiments, the UV-curable resin is selected from: isobornyl acrylate, isobornyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, carbamate acrylate, allyloxylated cyclohexyl diacrylate, bis(acryloyloxyethyl)hydroxyisocyanurate, bis(acryloyloxyneopentyl)adipate, bisphenol A diacrylate, bisphenol A dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol diacrylate. Ester, 1,3-Butanediol dimethacrylate, Dicyclopentyl diacrylate, Diethylene glycol diacrylate, Diethylene glycol dimethacrylate, Dipentaerythritol hexaacrylate, Dipentaerythritol monohydroxypentacrylate, Di(trimethylolpropane)tetraacrylate, Ethylene glycol dimethacrylate, Glyceryl methacrylate, 1,6-Hexanediol diacrylate, 1,6-Hexanediol dimethacrylate, Neopentyl glycol dimethacrylate, Neopentyl glycol hydroxyneopentate diacrylate, Pentaerythritol triacrylate Ester, Pentaerythritol Tetraacrylate, Dimethicone Phosphate, Polyethylene Glycol Diacrylate, Polypropylene Glycol Diacrylate, Tetraethylene Glycol Diacrylate, Tetrabromobisphenol A Diacrylate, Diethylene Glycol Divinyl Ether, Divinyl Triglyceride, Dimethylolpropane Triacrylate, Dimethylolpropane Triacrylate, Dimethylolpropane Triacrylate, Tripropylene Glycol Diacrylate, Tri(Acryloyloxyethyl) Isocyanurate, Triacrylate, Diacrylate, Propylene Acrylate Esters, vinyl-terminated polydimethylsiloxanes, vinyl-terminated diphenylsiloxane-dimethylsiloxane copolymers, vinyl-terminated polyphenylmethylsiloxanes, vinyl-terminated trifluoromethylsiloxane-dimethylsiloxane copolymers, vinyl-terminated diethylsiloxane-dimethylsiloxane copolymers, vinylmethylsiloxanes, monomethacryloyloxypropyl-terminated polydimethylsiloxanes, monovinyl-terminated polydimethylsiloxanes, monoallyl-monotrimethylsiloxy-terminated polyethylene oxides, and combinations thereof.

[0213] In some embodiments, the UV-curable resin is a mercapto-functionalized compound that can be crosslinked with isocyanates, epoxy resins, or unsaturated compounds under UV curing conditions. In some embodiments, the polythiol is pentaerythritol tetra(3-mercaptopropionate) (PETMP); trimethylolpropane tri(3-mercaptopropionate) (TMPMP); diol di(3-mercaptopropionate) (GDMP); tris[25-(3-mercaptopropionyloxy)ethyl]isocyanurate (TEMPIC); dipentaerythritol hexa(3-mercaptopropionate) (Di-PETMP); ethoxylated trimethylolpropane tri(3-mercaptopropionate) (ETTMP1300 and ETTMP 700); polycaprolactone tetra(3-mercaptopropionate) (PCL4MP 1350); pentaerythritol tetramercaptoacetate (PETMA); trimethylolpropane trimercaptoacetate (TMPMA); or diol dimercaptoacetate (GDMA). These compounds are marketed by Bruno Bock, Marschacht, Germany under trade names. Sale.

[0214] In some embodiments, the UV-curable resin is a polythiol. In some embodiments, the UV-curable resin is a polythiol selected from the following: ethylene glycol bis(thioglycolate), ethylene glycol bis(3-mercaptopropionate), trimethylolpropane tri(thioglycolate), trimethylolpropane tri(3-mercaptopropionate), pentaerythritol tetra(thioglycolate), pentaerythritol tetra(3-mercaptopropionate) (PETMP), and combinations thereof. In some embodiments, the UV-curable resin is PETMP.

[0215] In some embodiments, the UV-curable resin is a thiol-ene formulation comprising polythiols and 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (TTT). In some embodiments, the UV-curable resin is a thiol-ene formulation comprising PETMP and TTT.

[0216] In some embodiments, the UV-curable resin further comprises a photoinitiator. The photoinitiator initiates a crosslinking and / or curing reaction of the photosensitive material during exposure to light. In some embodiments, the photoinitiator is acetophenone-based, benzoin-based, or thioxanone-based.

[0217] In some embodiments, the photoinitiator is a vinyl acrylate-based resin. In some embodiments, the photoinitiator is MINS-311RM (Minuta Technology Co., Ltd., Korea).

[0218] In some implementations, the photoinitiator is 127, 184, 184D 2022, 2100, 250, 270, 2959, 369, 369EG, 379, 500, 651, 754, 784, 819, 819Dw, 907, 907FF, OxeOl, TPO-L, 1173, 1173D MBF (BASF Corporation, Wyandotte, MI). In some embodiments, the photoinitiator is TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide) or MBF (methylbenzoyl carbamate).

[0219] In some embodiments, the weight percentage of at least one organic resin in the nanostructure composition is between about 5% and about 99%, between about 5% and about 95%, between about 5% and about 90%, between about 5% and about 80%, between about 5% and about 70%, between about 5% and about 60%, between about 5% and about 50%, between about 5% and about 40%, between about 5% and about 30%, between about 5% and about 20%, between about 5% and about 10%, between about 10% and about 99%, between about 10% and about 95%, between about 10% and about 90%, between about 10% and about 80%, between about 10% and about 70%. Between 10% and 60%, between 10% and 50%, between 10% and 40%, between 10% and 30%, between 10% and 20%, between 20% and 99%, between 20% and 95%, between 20% and 90%, between 20% and 80%, between 20% and 70%, between 20% and 60%, between 20% and 50%, between 20% and 40%, between 20% and 30%, between 30% and 99%, between 30% and 95%, between 30% and 90%, approximately 3 Between 0% and approximately 80%, between approximately 30% and approximately 95%, between approximately 30% and approximately 90%, between approximately 30% and approximately 80%, between approximately 30% and approximately 70%, between approximately 30% and approximately 60%, between approximately 30% and approximately 50%, between approximately 30% and approximately 40%, between approximately 40% and approximately 99%, between approximately 40% and approximately 95%, between approximately 40% and approximately 90%, between approximately 40% and approximately 80%, between approximately 40% and approximately 70%, between approximately 40% and approximately 60%, between approximately 40% and approximately 50%, between approximately 50% and approximately 99%, between approximately 50% and approximately 95%, between approximately 50% and approximately 99%, between approximately 50% and approximately 95%, between approximately 50% and approximately 99%. Between 0%, between approximately 50% and approximately 80%, between approximately 50% and approximately 70%, between approximately 50% and approximately 60%, between approximately 60% and approximately 99%, between approximately 60% and approximately 95%, between approximately 60% and approximately 90%, between approximately 60% and approximately 80%, between approximately 60% and approximately 70%, between approximately 70% and approximately 99%, between approximately 70% and approximately 95%, between approximately 70% and approximately 90%, between approximately 70% and approximately 80%, between approximately 80% and approximately 99%, between approximately 80% and approximately 90%, between approximately 90% and approximately 99%, between approximately 90% and approximately 95%, or between approximately 95% and approximately 99%.

[0220] In some embodiments, the nanostructure composition further comprises at least one monomer incorporated into the ligands coated on the AIGS surface. AIGS nanostructures containing at least one monomer incorporated into the ligands coated on the AIGS surface have been found to exhibit high QY, good compatibility with HDDA (a commonly used monomer in inkjet printing inks), and good blue light absorption.

[0221] In some embodiments, the at least one monomer is an acrylate. Examples of acrylate monomers include, but are not limited to: methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, tridecyl methacrylate, stearyl methacrylate, decyl methacrylate, dodecyl methacrylate, diethylene glycol methacrylate, polypropylene glycol methacrylate, phenyl methacrylate, phenoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, tert-butylcyclohexyl methacrylate, behenyl methacrylate, dicyclopentyl methacrylate, dicyclopentenoxyethyl methacrylate, 2-methacrylate - Ethylhexyl methacrylate, octyl methacrylate, isooctyl methacrylate, n-decyl methacrylate, isodecyl methacrylate, lauryl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, benzyl methacrylate, 2-phenylethyl methacrylate, 2-phenoxyethyl acrylate, ethyl acrylate, methyl acrylate, n-butyl acrylate, 2-hydroxyethyl acrylate, 2-carboxyethyl acrylate, acrylic acid, ethylene glycol diacrylate, 1,3-propanediol diacrylate, 1,4-bis(acryloyloxy)acrylate, isobornyl acrylate, tetrahydrofurfuryl acrylate, cyclotrimethylolpropane acetal methacrylate, cyclohexyl methacrylate, and 4-tert-butylcyclohexyl acrylate.

[0222] In some embodiments, the monomer is at least one of ethyl acrylate, HDDA, tetrahydrofurfuryl acrylate, tris(propylene glycol) diacrylate, 1,4-bis(acryloyloxy)butane, or isobornyl acrylate.

[0223] Method for preparing AIGS nanostructured compositions

[0224] This disclosure provides a method for preparing nanostructured compositions, the method comprising:

[0225] (a) providing at least one AIGS nanostructure group; and

[0226] (b) Blending at least one organic resin with the composition of (a).

[0227] In some embodiments, the nanostructure has a pulsed wave size (PWL) between 480-545 nm, and at least about 80% of the emission is band-edge emission. In some embodiments, at least 80% of the emission is band-edge emission. In other embodiments, at least 90% of the emission is band-edge emission. In other embodiments, at least 95% of the emission is band-edge emission. In some embodiments, 92-98% of the emission is band-edge emission. In some embodiments, 93-96% of the emission is band-edge emission.

[0228] This disclosure also provides a method for preparing nanostructured compositions, the method comprising:

[0229] (a) Providing at least one group of AIGS nanostructures, wherein said nanostructures are prepared using a GaX3 (X = F, Cl, or Br) precursor and an oxygen-free ligand; and

[0230] (b) Blending at least one organic resin with the composition of (a).

[0231] In some implementations, the nanostructure has a pulse wave line (PWL) between 480-545 nm, and at least about 60% of the emission is band-edge emission.

[0232] This disclosure also provides a method for preparing nanostructured compositions, the method comprising:

[0233] (a) Providing at least one group of AIGS nanostructures, wherein the nanostructures have a band-edge emission level (PWL) between 480-545 nm, wherein at least about 80% of the emission is band-edge emission, and wherein the nanostructures exhibit 80-99% QY; and

[0234] (b) Blending at least one organic resin with the composition of (a).

[0235] In some embodiments, the at least one group of nanostructures is mixed with at least one organic resin at the following stirring rates: between about 100 rpm and about 10,000 rpm, between about 100 rpm and about 5,000 rpm, between about 100 rpm and about 3,000 rpm, between about 100 rpm and about 1,000 rpm, between about 100 rpm and about 500 rpm, between about 500 rpm and about 10,000 rpm, between about 500 rpm and about 5,000 rpm, between about 500 rpm and about 3,000 rpm, between about 500 rpm and about 1,000 rpm, between about 1,000 rpm and about 10,000 rpm, between about 1,000 rpm and about 5,000 rpm, between about 1,000 rpm and about 3,000 rpm, between about 3,000 rpm and about 10,000 rpm, or between about 5,000 rpm and about 10,000 rpm.

[0236] In some embodiments, the at least one group of nanostructures is mixed with at least one organic resin for the following durations: between about 10 minutes and about 24 hours, between about 10 minutes and about 20 hours, between about 10 minutes and about 15 hours, between about 10 minutes and about 10 hours, between about 10 minutes and about 5 hours, between about 10 minutes and about 1 hour, between about 10 minutes and about 30 minutes, between about 30 minutes and about 24 hours, between about 30 minutes and about 20 hours, between about 30 minutes and about 15 hours, between about 30 minutes and about 10 hours, and between about 30 minutes and about 10 hours. Between minutes and about 5 hours, between about 30 minutes and about 1 hour, between about 1 hour and about 24 hours, between about 1 hour and about 20 hours, between about 1 hour and about 15 hours, between about 1 hour and about 10 hours, between about 1 hour and about 5 hours, between about 5 hours and about 24 hours, between about 5 hours and about 20 hours, between about 5 hours and about 15 hours, between about 5 hours and about 10 hours, between about 10 hours and about 15 hours, between about 15 hours and about 24 hours, between about 15 hours and about 20 hours, or between about 20 hours and about 24 hours.

[0237] In some embodiments, the at least one group of nanostructures is blended with at least one organic resin at temperatures between about -5°C and about 100°C, between about -5°C and about 75°C, between about -5°C and about 50°C, between about -5°C and about 23°C, between about 23°C and about 100°C, between about 23°C and about 75°C, between about 23°C and about 50°C, between about 50°C and about 100°C, between about 50°C and about 75°C, or between about 75°C and about 100°C. In some embodiments, the at least one organic resin is blended with the at least one group of nanostructures at a temperature between about 23°C and about 50°C.

[0238] In some embodiments, if more than one organic resin is used, the organic resins are added and mixed together. In some embodiments, the first organic resin and the second organic resin are mixed at the following stirring rates: between approximately 100 rpm and approximately 10,000 rpm, between approximately 100 rpm and approximately 5,000 rpm, between approximately 100 rpm and approximately 3,000 rpm, between approximately 100 rpm and approximately 1,000 rpm, between approximately 100 rpm and approximately 500 rpm, between approximately 500 rpm and approximately 10,000 rpm, between approximately 500 rpm and approximately 5,000 rpm, and between approximately 5... Between 00 rpm and approximately 3,000 rpm, between approximately 500 rpm and approximately 1,000 rpm, between approximately 1,000 rpm and approximately 10,000 rpm, between approximately 1,000 rpm and approximately 5,000 rpm, between approximately 1,000 rpm and approximately 3,000 rpm, between approximately 3,000 rpm and approximately 10,000 rpm, between approximately 3,000 rpm and approximately 10,000 rpm, or between approximately 5,000 rpm and approximately 10,000 rpm.

[0239] In some embodiments, the first organic resin is mixed with the second organic resin for the following durations: between about 10 minutes and about 24 hours, between about 10 minutes and about 20 hours, between about 10 minutes and about 15 hours, between about 10 minutes and about 10 hours, between about 10 minutes and about 5 hours, between about 10 minutes and about 1 hour, between about 10 minutes and about 30 minutes, between about 30 minutes and about 24 hours, between about 30 minutes and about 20 hours, between about 30 minutes and about 15 hours, between about 30 minutes and about 10 hours, between about 30 minutes and about 5 hours, between about 30 minutes and about 1 hour, between about 1 hour and about 24 hours, between about 1 hour and about 20 hours, approximately... Between 1 hour and about 15 hours, between about 1 hour and about 10 hours, between about 1 hour and about 5 hours, between about 5 hours and about 24 hours, between about 5 hours and about 20 hours, between about 5 hours and about 15 hours, between about 1 hour and about 10 hours, between about 1 hour and about 5 hours, between about 5 hours and about 24 hours, between about 5 hours and about 20 hours, between about 5 hours and about 15 hours, between about 5 hours and about 10 hours, between about 10 hours and about 24 hours, between about 10 hours and about 20 hours, between about 10 hours and about 15 hours, between about 15 hours and about 24 hours, between about 15 hours and about 20 hours, or between about 20 hours and about 24 hours.

[0240] In some embodiments, the AIGS nanostructure is combined with at least one monomer incorporated into the ligands coated on the AIGS surface prior to combination with the resin. In some embodiments, the monomer is an acrylate. In some embodiments, the monomer is at least one selected from ethyl acrylate, HDDA, tetrahydrofurfuryl acrylate, tris(propylene glycol) diacrylate, 1,4-bis(acryloyloxy)butane, or isobornyl acrylate.

[0241] Properties of AIGS Nanostructures

[0242] In some embodiments, the AIGS nanostructure exhibits a high photoluminescence quantum yield. In some embodiments, the nanostructure exhibits a photoluminescence quantum yield between approximately 50% and approximately 99%, between approximately 50% and approximately 95%, between approximately 50% and approximately 90%, between approximately 50% and approximately 85%, between approximately 50% and approximately 80%, between approximately 50% and approximately 70%, between approximately 50% and approximately 60%, between approximately 60% and approximately 99%, between approximately 60% and approximately 95%, between approximately 60% and approximately 90%, between approximately 60% and approximately 85%, between approximately 60% and approximately 80%, between approximately 60% and approximately 70%, and between approximately 70% and approximately 99%. Between approximately 70% and approximately 95%, between approximately 70% and approximately 90%, between approximately 70% and approximately 85%, between approximately 70% and approximately 80%, between approximately 80% and approximately 99%, between approximately 80% and approximately 95%, between approximately 80% and approximately 90%, between approximately 80% and approximately 85%, between approximately 85% and approximately 99%, between approximately 85% and approximately 95%, between approximately 80% and approximately 85%, between approximately 85% and approximately 99%, between approximately 85% and approximately 90%, between approximately 90% and approximately 99%, between approximately 90% and approximately 95%, or between approximately 95% and approximately 99%. In some embodiments, the nanostructure exhibits photoluminescence quantum yields between approximately 82% and approximately 96%, between approximately 85% and approximately 96%, and between approximately 93% and approximately 94%.

[0243] The photoluminescence spectrum of the nanostructure can cover a broad, desired portion of the spectrum. In some embodiments, the photoluminescence spectrum of the nanostructure has emission maxima between 300 nm and 750 nm, 300 nm and 650 nm, 300 nm and 550 nm, 300 nm and 450 nm, 450 nm and 750 nm, 450 nm and 650 nm, 450 nm and 550 nm, 450 nm and 750 nm, 450 nm and 650 nm, 450 nm and 550 nm, 550 nm and 750 nm, 550 nm and 650 nm, or 650 nm and 750 nm. In some embodiments, the photoluminescence spectrum of the nanostructure has an emission maxima between 450 nm and 550 nm.

[0244] The size distribution of the nanostructures can be relatively narrow. In some embodiments, the photoluminescence spectrum of the nanostructure group can have a full width at half maximum (FWHM) between 10 nm and 60 nm, 10 nm and 40 nm, 10 nm and 30 nm, 10 nm and 20 nm, 20 nm and 60 nm, 20 nm and 40 nm, 20 nm and 30 nm, 25 nm and 60 nm, 25 nm and 40 nm, 25 nm and 30 nm, 30 nm and 60 nm, 30 nm and 40 nm, or 40 nm and 60 nm. In some embodiments, the photoluminescence spectrum of the nanostructure group can have a FWHM between 24 nm and 50 nm.

[0245] In some embodiments, the nanostructure emits light with a peak emission wavelength (PWL) between about 400 nm and about 650 nm, between about 400 nm and about 600 nm, between about 400 nm and about 550 nm, between about 400 nm and about 500 nm, between about 400 nm and about 450 nm, between about 450 nm and about 650 nm, between about 450 nm and about 600 nm, between about 450 nm and about 550 nm, between about 450 nm and about 500 nm, between about 500 nm and about 650 nm, between about 500 nm and about 600 nm, between about 500 nm and about 550 nm, between about 550 nm and about 650 nm, between about 550 nm and about 600 nm, or between about 600 nm and about 650 nm. In some embodiments, the nanostructure emits light with a PWL between about 500 nm and about 550 nm.

[0246] As a predicted value for blue light absorption efficiency, the optical density (OD) at 450 nm is based on mass. 450 The optical density (OD) of the nanostructure solution can be calculated as follows: measure the optical density of the nanostructure solution in a cuvette with a path length of 1 cm and divide by the dry mass per mL of the same solution after all volatiles have been removed under vacuum (<200 mTorr). In some embodiments, the optical density (OD) of the nanostructure at 450 nm is based on the mass. 450 The dosage (by weight) is between 0.28 mg and about 0.5 mg, between 0.28 mg and about 0.4 mg, between 0.28 mg and about 0.35 mg, between 0.28 mg and about 0.32 mg, between about 0.32 mg and about 0.5 mg, between about 0.32 mg and about 0.4 mg, between about 0.32 mg and about 0.35 mg, between about 0.35 mg and about 0.5 mg, between about 0.35 mg and about 0.4 mg, or between about 0.4 mg and about 0.5 mg.

[0247] membrane

[0248] The nanostructures of the present invention can be embedded in a polymer matrix using any suitable method. As used herein, the term "embedded" is used to indicate that the nanostructures are surrounded or encapsulated by a polymer that constitutes the main component of the matrix. In some embodiments, the at least one group of nanostructures is suitably uniformly distributed throughout the matrix. In some embodiments, the at least one group of nanostructures is distributed according to an application-specific distribution. In some embodiments, the nanostructures are mixed in a polymer and applied to the surface of a substrate.

[0249] In some embodiments, this disclosure provides nanostructured films comprising:

[0250] (a) A composition comprising at least one AIGS nanostructure group and at least one ligand bound to said nanostructure; and

[0251] (b) At least one organic resin.

[0252] In some embodiments, a portion of the ligand binds to the nanostructure. In other embodiments, the surface of the nanostructure is saturated with the ligand.

[0253] In some implementations, the nanostructure has a PWL between 480 and 545 nm.

[0254] In some embodiments, the composition comprising at least one AIGS nanostructure group further comprises at least one monomer incorporated into the ligands coated on the AIGS surface. In some embodiments, the at least one monomer is an acrylate. In some embodiments, the monomer is at least one selected from ethyl acrylate, HDDA, tetrahydrofurfuryl acrylate, tris(propylene glycol)diacrylate, 1,4-bis(acryloyloxy)butane, or isobornyl acrylate.

[0255] This disclosure also provides methods for preparing nanostructured films, including:

[0256] (a) providing at least one AIGS nanostructure group; and

[0257] (b) Blending at least one organic resin with the composition of (a).

[0258] In some implementations, the nanostructure has a PWL between 480 and 545 nm.

[0259] In some embodiments, at least 80% of the transmissions are edge-triggered. In other embodiments, at least 90% of the transmissions are edge-triggered. In other embodiments, at least 95% of the transmissions are edge-triggered. In some embodiments, 92-98% of the transmissions are edge-triggered. In some embodiments, 93-96% of the transmissions are edge-triggered.

[0260] In some embodiments, the nanostructure composition further comprises an amino ligand having formula I:

[0261]

[0262] in:

[0263] x is between 1 and 100;

[0264] y is between 0 and 100; and

[0265] R 2 It is C 1-20 alkyl.

[0266] In some embodiments, x is 1 to 100, 1 to 50, 1 to 20, 1 to 10, 1 to 5, 5 to 100, 5 to 50, 5 to 20, 5 to 10, 10 to 100, 10 to 50, 10 to 20, 20 to 100, 20 to 50, or 50 to 100. In some embodiments, x is 10 to 50. In some embodiments, x is 10 to 20. In some embodiments, x is 1. In some embodiments, x is 19. In some embodiments, x is 6. In some embodiments, x is 10.

[0267] In some implementations, R 2 It is C 1-20 Alkyl group. In some embodiments, R 2 It is C 1-10 Alkyl group. In some embodiments, R 2 It is C 1-5 Alkyl group. In some embodiments, R 2 It is -CH2CH3.

[0268] In some embodiments, the compound of formula I is an amine-terminated polymer commercially available from Huntsman Petrochemical Corporation. In some embodiments, the amine-terminated polymer of formula (VI) has x = 1, y = 9, and R 2=-CH3, and is JEFFAMINE M-600 (Huntsman Petrochemical Corporation, Texas). JEFFAMINE M-600 has a molecular weight of approximately 600. In some embodiments, the amine-terminated polymer of formula (III) has x = 19, y = 3, and R 2 =-CH3, and is JEFFAMINE M-1000 (Huntsman Petrochemical Corporation, Texas). JEFFAMINE M-1000 has a molecular weight of about 1,000. In some embodiments, the amine-terminated polymer of formula (III) has x=6, y=29 and R 2 =-CH3, and is JEFFAMINE M-2005 (Huntsman Petrochemical Corporation, Texas). JEFFAMINE M-2005 has a molecular weight of about 2,000. In some embodiments, the amine-terminated polymer of formula (III) has x=31, y=10, and R 2 =-CH3, and is JEFFAMINE M-2070 (Huntsman Petrochemical Corporation, Texas). JEFFAMINE M-2070 has a molecular weight of about 2,000. In another embodiment, the ligand is a polyethylene glycol amine available from CreativePEGWorks, such as PEG550-amine and PEG350-amine.

[0269] In some implementations, the nanostructured film is a color conversion layer.

[0270] The nanostructured composition can be deposited by any suitable method known in the art, including but not limited to: painting, spraying, solvent spraying, wet coating, adhesive coating, spin coating, tape coating, roll coating, flow coating, inkjet vapor jetting, drop casting, doctor blade coating, fog deposition, or combinations thereof. In some embodiments, the nanostructured composition is cured after deposition. Suitable curing methods include photocuring (such as UV curing) and thermal curing. Conventional lamination processes, tape coating methods, and / or roll-to-roll manufacturing methods can be used to form the nanostructured films of the present invention. The nanostructured composition can be directly coated onto the desired layer of a substrate. Alternatively, the nanostructured composition can be formed as a solid layer as a separate element and then applied to the substrate. In some embodiments, the nanostructured composition can be deposited on one or more barrier layers.

[0271] Spin coating

[0272] In some embodiments, spin coating is used to deposit nanostructured compositions onto a substrate. In spin coating, a small amount of material is typically deposited onto the center of a substrate mounted on a machine called a spinner, which is held in place by a vacuum. The substrate is rotated at high speed by the spinner, causing centrifugal forces to diffuse the material from the center to the edges of the substrate. While most of the material is spinned out, a certain amount remains on the substrate, forming a film on the surface as rotation continues. The final thickness of the film is determined by the properties of the deposited material and the substrate, and by the parameters chosen for the spin process, such as rotation speed, acceleration, and rotation time. For typical films, rotation speeds of 1500 to 6000 rpm and rotation times of 10–60 seconds are used. In some embodiments, films are deposited at very low speeds, such as less than 1000 rpm. In some embodiments, films are cast at approximately 300, 400, 500, 600, 700, 800, or 900 rpm.

[0273] Mist deposition

[0274] In some implementations, mist deposition is used to deposit nanostructure compositions onto a substrate. Mist deposition occurs at room temperature and atmospheric pressure, allowing for precise control of film thickness by varying process conditions. During mist deposition, the liquid source material is atomized into a very fine mist and transported to the deposition chamber via nitrogen. The mist is then drawn to the wafer surface by a high-voltage potential between the field screen and the wafer holder. Once the droplets coalesce on the wafer surface, the wafer is removed from the chamber and thermally cured to evaporate the solvent. The liquid precursor is a mixture of solvent and material to be deposited. It is transported to the atomizer via pressurized nitrogen. Price, SC. ​​et al., “Formation of Ultra-Thin Quantum Dot Films by Mist Deposition,” ESC Transactions 11:89-94 (2007).

[0275] Spraying

[0276] In some embodiments, spraying is used to deposit nanostructured compositions onto a substrate. Typical equipment for spraying includes a nozzle, an atomizer, a precursor solution, and a carrier gas. In a spray deposition process, the precursor solution is broken into micro-sized droplets by a carrier gas or by atomization (e.g., ultrasonic, air blast, or electrostatic). Droplets exiting the atomizer are accelerated onto the substrate surface through the nozzle with the aid of the carrier gas, which is controlled and regulated as needed. The relative movement between the nozzle and the substrate is designed to achieve complete coverage of the substrate.

[0277] In some embodiments, the application of the nanostructure composition further includes a solvent. In some embodiments, the solvent used to apply the nanostructure composition is water, an organic solvent, an inorganic solvent, a halogenated organic solvent, or a mixture thereof. Illustrative solvents include, but are not limited to: water, D2O, acetone, ethanol, dioxane, ethyl acetate, methyl ethyl ketone, isopropanol, anisole, γ-butyrolactone, dimethylformamide, N-methylpyrrolidone, dimethylacetamide, hexamethylphosphoramide, toluene, dimethyl sulfoxide, cyclopentanone, tetramethylene sulfoxide, xylene, ε-caprolactone, tetrahydrofuran, tetrachloroethylene, chloroform, chlorobenzene, dichloromethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, or a mixture thereof.

[0278] Inkjet printing

[0279] Solvents suitable for nanostructure inkjet printing are known to those skilled in the art. In some embodiments, the organic solvent is a substituted aromatic or heteroaromatic solvent, as described in U.S. Patent Application Publication No. 2018 / 0230321, which is incorporated herein by reference in its entirety.

[0280] In some embodiments, the organic solvents used in the nanostructure compositions as inkjet printing formulations are defined by their boiling point, viscosity, and surface tension. The properties of organic solvents suitable for inkjet printing formulations are shown in Table 1.

[0281] Table 1: Properties of organic solvents used in inkjet printing formulations

[0282] solvent Boiling point (°C) Viscosity (mPa·s) Surface tension (dyne / cm) 1-Methylnaphthalene 240 3.3 38 1-Methoxynaphthalene 270 7.2 43 3-Phenoxytoluene 271 4.8 37 Dibenzyl ether 298 8.7 39 benzyl benzoate 324 10.0 44 Butyl benzoate 249 2.7 34 Hexyl benzoate 272 — — Octylbenzene 265 2.6 31 Cyclohexylbenzene 240 2.0 34 hexadecane 287 3.4 28 4-Methyl anisole 179 — 29

[0283] In some embodiments, the organic solvent has a boiling point between about 150°C and about 350°C at 1 atm. In other embodiments, the organic solvent has a boiling point between about 150°C and about 350°C, between about 150°C and about 300°C, between about 150°C and about 250°C, between about 150°C and about 200°C, between about 200°C and about 350°C, between about 200°C and about 250°C, between about 250°C and about 350°C, between about 250°C and about 300°C, or between about 300°C and about 350°C.

[0284] In some embodiments, the viscosity of the organic solvent is between about 1 mPa·s and about 15 mPa·s. In some embodiments, the viscosity of the organic solvent is between about 1 mPa·s and about 15 mPa·s, between about 1 mPa·s and about 10 mPa·s, between about 1 mPa·s and about 8 mPa·s, between about 1 mPa·s and about 6 mPa·s, between about 1 mPa·s and about 4 mPa·s, between about 1 mPa·s and about 2 mPa·s, between about 2 mPa·s and about 15 mPa·s, between about 2 mPa·s and about 10 mPa·s, between about 2 mPa·s and about 8 mPa·s, between about 2 mPa·s and about 6 mPa·s, and about 2 mPa·s. Between Pa·s and about 4 mPa·s, between about 4 mPa·s and about 15 mPa·s, between about 4 mPa·s and about 10 mPa·s, between about 4 mPa·s and about 8 mPa·s, between about 4 mPa·s and about 6 mPa·s, between about 6 mPa·s and about 15 mPa·s, between about 6 mPa·s and about 10 mPa·s, between about 6 mPa·s and about 8 mPa·s, between about 8 mPa·s and about 15 mPa·s, between about 8 mPa·s and about 10 mPa·s, or between about 10 mPa·s and about 15 mPa·s.

[0285] In some embodiments, the organic solvent has a surface tension between about 20 dyne / cm and about 50 dyne / cm. In some embodiments, the surface tension of the organic solvent is between about 20 dyne / cm and about 50 dyne / cm, between about 20 dyne / cm and about 40 dyne / cm, between about 20 dyne / cm and about 35 dyne / cm, between about 20 dyne / cm and about 30 dyne / cm, between about 20 dyne / cm and about 25 dyne / cm, between about 25 dyne / cm and about 50 dyne / cm, between about 25 dyne / cm and about 40 dyne / cm, and about 25 dyne / cm. Between dyne / cm and approximately 35 dyne / cm, between approximately 25 dyne / cm and approximately 30 dyne / cm, between approximately 30 dyne / cm and approximately 50 dyne / cm, between approximately 30 dyne / cm and approximately 40 dyne / cm, between approximately 30 dyne / cm and approximately 35 dyne / cm, between approximately 35 dyne / cm and approximately 50 dyne / cm, between approximately 35 dyne / cm and approximately 40 dyne / cm, or between approximately 40 dyne / cm and approximately 50 dyne / cm.

[0286] In some embodiments, the organic solvent used in the nanostructure composition is alkylnaphthalene, alkoxynaphthalene, alkylbenzene, aryl, alkyl-substituted benzene, cycloalkylbenzene, C9-C 20 Alkane, diaryl ether, alkyl benzoate, aryl benzoate or alkoxy-substituted benzene.

[0287] In some embodiments, the organic solvent used in the nanostructure composition is 1-tetrahydronaphthone, 3-phenoxytoluene, acetophenone, 1-methoxynaphthyl, n-octylbenzene, n-nonylbenzene, 4-methylanisole, n-decylbenzene, p-diisopropylbenzene, pentylbenzene, 1,2,3,4-tetrahydronaphthyl, cyclohexylbenzene, chloronaphthyl, 1,4-dimethylnaphthyl, 3-isopropylbiphenyl, p-methylcumene, dipentylbenzene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, butylbenzene, dodecylbenzene, 1-methylnaphthyl, 1,2,4-trichlorobenzene, diphenyl ether, diphenylmethane, 4-isopropylbiphenyl, benzyl benzoate, 1,2-bis(3,4-dimethylphenyl)ethane, 2-isopropylnaphthyl, dibenzyl ether, or combinations thereof. In some embodiments, the organic solvent used in the nanostructure composition is 1-methylnaphthalene, n-octylbenzene, 1-methoxynaphthalene, 3-phenoxytoluene, cyclohexylbenzene, 4-methylanisole, n-decylbenzene, or a combination thereof.

[0288] In some embodiments, the organic solvent is an anhydrous organic solvent. In some embodiments, the organic solvent is substantially anhydrous organic solvent.

[0289] In some embodiments, the organic solvent is a non-volatile monomer or a combination of monomers selected from the list presented above.

[0290] In some embodiments, the weight percentage of the organic solvent in the nanostructure composition is between about 70% and about 99%. In other embodiments, the weight percentage of the organic solvent in the nanostructure composition is between: about 70% and about 99%, between about 70% and about 98%, between about 70% and about 95%, between about 70% and about 90%, between about 70% and about 85%, between about 70% and about 80%, between about 70% and about 75%, between about 75% and about 99%, between about 75% and about 98%, between about 75% and about 95%, between about 75% and about 90%, and between about 75% and about 85%. The percentages are between approximately 75% and approximately 80%, between approximately 80% and approximately 99%, between approximately 80% and approximately 98%, between approximately 80% and approximately 95%, between approximately 80% and approximately 90%, between approximately 80% and approximately 85%, between approximately 85% and approximately 99%, between approximately 85% and approximately 98%, between approximately 85% and approximately 95%, between approximately 85% and approximately 90%, between approximately 90% and approximately 95%, between approximately 95% and approximately 99%, between approximately 95% and approximately 98%, or between approximately 98% and approximately 99%. In some embodiments, the weight percentage of the organic solvent in the nanostructure composition is between approximately 95% and approximately 99%.

[0291] In some embodiments, the composition for inkjet printing further comprises a monomer incorporated into the ligands coated on the AIGS surface. In some embodiments, the monomer is an acrylate. In some embodiments, the monomer is at least one selected from ethyl acrylate, HDDA, tetrahydrofurfuryl acrylate, tris(propylene glycol)diacrylate, 1,4-bis(aranyloxy)butane (incorporated into the ligands coated on the AIGS surface), or isobornyl acrylate. It has been found that the use of monomers in inkjet compositions provides better compatibility with the AIGS nanostructures in the inkjet composition, improves QY, and improves blue light absorption.

[0292] Film curing

[0293] In some embodiments, the composition is thermally cured to form a nanostructured layer. In some embodiments, a UV-curable composition is used. In some embodiments, the nanostructured composition is directly coated onto a barrier layer of the nanostructured film, and subsequently, an additional barrier layer is deposited on the nanostructured layer to produce the nanostructured film. A support substrate may be used under the barrier film to increase strength, stability, and coating uniformity, and to prevent material inconsistencies, bubble formation, and wrinkling or folding of the barrier layer material or other materials. Additionally, one or more barrier layers may be deposited on the nanostructured layer to seal the material between the top and bottom barrier layers. Suitably, the barrier layer may be deposited as a laminate and optionally sealed or further processed before the nanostructured film is incorporated into a specific lighting device. As will be understood by those skilled in the art, the nanostructured composition deposition process may include additional or varied components. Such embodiments will allow for in-line process tuning of the nanostructure emission characteristics, such as brightness and color (e.g., to adjust the quantum dot white point) as well as the nanostructured film thickness and other properties. Furthermore, these implementations will allow for periodic testing of the nanostructured membrane properties during production, as well as any necessary switching to achieve precise nanostructured membrane properties. This testing and adjustment can also be performed without altering the mechanical configuration of the processing line, as the appropriate amounts of the mixture used to form the nanostructured membrane can be electronically changed using a computer program.

[0294] It has been found that nanostructured films with high PCE can be obtained when the films are processed without exposing the AIGS nanocrystals to blue or UV light, prior to providing an oxygen-free environment for the nanostructures. The oxygen-free environment can be provided as follows:

[0295] (a) Encapsulating the membrane with an oxygen barrier before heat treatment and / or exposure to blue light for PCE measurement;

[0296] (b) Using oxygen-reactive materials as part of the formulation during heat treatment or light exposure; and / or

[0297] (c) Temporarily block oxygen by using a sacrificial barrier layer.

[0298] In some implementations, improvements to the PCE can be achieved through any method capable of forming an oxygen barrier layer on the AIGS layer. In the mass production of devices incorporating these AIGS-CC layers, encapsulation can be performed using vapor deposition processes. In this case, a typical process flow involves inkjet printing of the AIGS layer, followed by UV curing, baking at 180°C to remove volatiles, deposition of an organic planarization layer, and then deposition of an inorganic barrier layer. Techniques for depositing the inorganic layer can include atomic layer deposition (ALD), molecular layer deposition (MLD), chemical vapor deposition (CVD) (with or without plasma enhancement), pulsed vapor deposition (PVD), sputtering, or metal evaporation. Other potential encapsulation methods include solution-treated or printed organic layers, UV or thermosetting adhesives, lamination using barrier films, and so on.

[0299] In some embodiments, the membrane is encapsulated in an inert atmosphere. In some embodiments, the membrane is encapsulated in a nitrogen or argon atmosphere.

[0300] Oxygen-reactive materials include any material that is more reactive to oxygen than AIGS nanostructures. Examples of oxygen-reactive materials include, but are not limited to, phosphine, phosphites, organometallic precursors, titanium nitride, and tantalum nitride. In some embodiments, phosphine may be C 1-20 Any of the trialkylphosphines. In one embodiment, the phosphine is trioctylphosphine. In some embodiments, the phosphite may be a trialkylphosphite, an alkylarylphosphite, or a triarylphosphite. In some embodiments, the metal-organic precursor may be trialkylaluminum, trialkylgallium, trialkylindium, dialkylzinc, etc.

[0301] Examples of sacrificial barrier layers include polymer layers that can be dissolved in and washed away in a solvent. Examples of such polymers include, but are not limited to, polyvinyl alcohol, polyvinyl acetate, and polyethylene glycol. Other examples of sacrificial barrier layers include inorganic compounds or salts such as lithium silicate and lithium fluoride. Examples of solvents that can be used to wash away the sacrificial layer include water and organic solvents such as alcohols (e.g., ethanol, methanol), halogenated hydrocarbons (e.g., dichloromethane and vinyl chloride), aromatic hydrocarbons (e.g., toluene, xylene), aliphatic hydrocarbons (e.g., hexane, octane, octadecene), tetrahydrofuran, C 4-20 Ethers such as diethyl ether, and C 2-20 Esters, such as ethyl acetate.

[0302] Characteristics and implementation methods of nanostructured membranes

[0303] In some embodiments, the nanostructured film of the present invention is used to form a display device. As used herein, a display device refers to any system having a lighting display. Such devices include, but are not limited to, devices encompassing: liquid crystal displays (LCDs), televisions, computers, mobile phones, smartphones, personal digital assistants (PDAs), gaming devices, e-readers, digital cameras, augmented reality / virtual reality (AR / VR) glasses, light projection systems, head-up displays, and so on.

[0304] In some implementations, the nanostructured film is part of a nanostructured color conversion layer.

[0305] In some embodiments, the display device includes a nanostructured color converter. In some embodiments, the display device includes a backplane; a display panel disposed on the backplane; and a nanostructured layer. In some embodiments, the nanostructured layer is disposed on the display panel. In some embodiments, the nanostructured layer includes a patterned nanostructured layer.

[0306] In some implementations, the backplane includes a blue LED, LCD, OLED, or microLED.

[0307] In some embodiments, the nanostructured layer is disposed on the light source element. In some embodiments, the nanostructured layer comprises a patterned nanostructured layer. The patterned nanostructured layer can be prepared by any method known in the art. In one embodiment, the patterned nanostructured layer is prepared by inkjet printing of a nanostructured solution. Suitable solvents for the solution include, but are not limited to, dipropylene glycol monomethyl ether acetate (DPMA), polyglycidyl methacrylate (PGMA), diethylene glycol monoethyl ether acetate (EDGAC), and propylene glycol methyl ether acetate (PGMEA). Volatile solvents can also be used for inkjet printing because they allow for rapid drying. Volatile solvents include ethanol, methanol, 1-propanol, 2-propanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, and tetrahydrofuran. Alternatively, “solvent-free” inks in which the AIGS nanostructures are dispersed in ink monomers can be used for inkjet printing.

[0308] In some embodiments, AIGS nanostructures are inkjet printed using a composition further comprising at least one monomer incorporated into the ligands coated on the AIGS surface. In some embodiments, the at least one monomer is an acrylate. In some embodiments, the acrylate is at least one selected from ethyl acrylate, tetrahydrofurfuryl acrylate, tris(propylene glycol)diacrylate, 1,4-bis(acryloyloxy)butane, or isobornyl acrylate. It has been found that AIGS nanostructures treated with at least one monomer during ligand exchange provide better compatibility with HDDA (a commonly used monomer in inkjet-printable inks), improving QY and blue light absorption.

[0309] In some embodiments, the thickness of the nanostructured layer is between about 1 μm and about 25 μm. In some embodiments, the thickness of the nanostructured layer is between about 5 μm and about 25 μm. In some embodiments, the thickness of the nanostructured layer is between about 10 μm and about 12 μm.

[0310] In some embodiments, the nanostructured display device exhibits a PCE of at least 32%. In some embodiments, the nanostructured molded article exhibits a PCE of 32-40%. In some embodiments, nanostructured molded articles exhibit PCE of 33%-40%, 34%-40%, 35%-40%, 36%-40%, 37%-40%, 38%-40%, 39%-40%, 33%-39%, 34%-39%, 35%-39%, 36%-39%, 37%-39%, 38%-39%, 33%-38%, 34%-38%, 35%-38%, 36%-38%, 37%-38%, 33%-37%, 34%-37%, 35%-37%, 36%-37%, 33%-36%, 34%-36%, 35%-36%, 33%-35%, or 34%-35%.

[0311] In some embodiments, the optical film comprising the nanostructure layer is substantially cadmium-free. As used herein, the term "substantially cadmium-free" means that the nanostructure composition contains less than 100 ppm by weight of cadmium. The RoHS compliance definition requires the presence of no more than 0.01 wt% (100 ppm) of cadmium in the original homogeneous precursor material. Cadmium concentration can be measured by inductively coupled plasma mass spectrometry (ICP-MS) analysis and is at the parts-per-billion (ppb) level. In some embodiments, the "substantially cadmium-free" optical film contains 10 ppm to 90 ppm of cadmium. In other embodiments, the substantially cadmium-free optical film contains less than about 50 ppm, less than about 20 ppm, less than about 10 ppm, or less than about 1 ppm of cadmium.

[0312] Nanostructured molded products

[0313] In some embodiments, this disclosure provides nanostructured molded articles comprising:

[0314] (a) First barrier layer;

[0315] (b) the second barrier layer; and

[0316] (c) A nanostructure layer between the first barrier layer and the second barrier layer, wherein the nanostructure layer comprises a group of nanostructures containing AIGS nanostructures; and at least one organic resin.

[0317] In some implementations, the nanostructure has a PWL between 480 and 545 nm.

[0318] In some embodiments, at least 80% of the emission is edge-emission. In other embodiments, at least 90% of the emission is edge-emission. In other embodiments, at least 95% of the emission is edge-emission. In some embodiments, 92-98% of the emission is edge-emission. In some embodiments, 93-96% of the emission is edge-emission. In some embodiments, the nanostructured molded article exhibits at least 32% PCE. In some embodiments, the nanostructured molded article exhibits 32-40% PCE. In some embodiments, nanostructured molded articles exhibit PCE of 33%-40%, 34%-40%, 35%-40%, 36%-40%, 37%-40%, 38%-40%, 39%-40%, 33%-39%, 34%-39%, 35%-39%, 36%-39%, 37%-39%, 38%-39%, 33%-38%, 34%-38%, 35%-38%, 36%-38%, 37%-38%, 33%-37%, 34%-37%, 35%-37%, 36%-37%, 33%-36%, 34%-36%, 35%-36%, 33%-35%, or 34%-35%.

[0319] Barrier layer

[0320] In some embodiments, the nanostructured molded article includes one or more barrier layers disposed on either or both sides of the nanostructured layer. Suitable barrier layers protect the nanostructured layer and the nanostructured molded article from environmental conditions such as high temperatures, oxygen, and moisture. Suitable barrier materials include non-yellowing transparent optical materials that are hydrophobic, chemically and mechanically compatible with the nanostructured molded article, exhibit photostability and chemical stability, and can withstand high temperatures. In some embodiments, the one or more barrier layers are index-matched to the refractive index of the nanostructured molded article. In some embodiments, the matrix material of the nanostructured molded article and one or more adjacent barrier layers are refractively matched to have similar refractive indices, such that most of the light transmitted through the barrier layers toward the nanostructured molded article is transmitted from the barrier layers into the nanostructured layer. This refractive index matching reduces light loss at the interface between the barrier layer and the matrix material.

[0321] The barrier layer is suitably a solid material and may be a cured liquid, gel, or polymer. Depending on the specific application, the barrier layer may comprise flexible or non-flexible materials. The barrier layer is typically a planar layer and may include any suitable shape and surface area configuration depending on the specific lighting application. In some embodiments, the one or more barrier layers will be compatible with lamination processing techniques, thereby disposing a nanostructured layer on at least a first barrier layer and at least a second barrier layer on the opposite side of the nanostructured layer to form a nanostructured molded article according to an embodiment of the invention. Suitable barrier materials include any suitable barrier materials known in the art. For example, suitable barrier materials include glass, polymers, and oxides. Suitable barrier layer materials include, but are not limited to: polymers, such as polyethylene terephthalate (PET); oxides, such as silicon oxides, titanium oxides, or aluminum oxides (e.g., SiO2, Si2O3, TiO2, or Al2O3); and suitable combinations thereof. In some embodiments, each barrier layer of the nanostructured molded article comprises at least two layers containing different materials or compositions, such that the multilayer barrier eliminates or reduces pinhole alignment in the barrier layers, thereby providing effective protection against oxygen and moisture penetration into the nanostructured layer. The nanostructured layer may include any suitable material or combination of materials and any suitable number of barrier layers on either side or both sides of the nanostructured layer. The material, thickness, and number of barrier layers will depend on the specific application and will be appropriately selected to maximize the barrier protection and brightness of the nanostructured layer while minimizing the thickness of the nanostructured molded article. In some embodiments, each barrier layer comprises a laminate, and in some embodiments, a double-laminated film, wherein each barrier layer is thick enough to eliminate wrinkling in roll-to-roll or lamination manufacturing processes. In embodiments where the nanostructure contains heavy metals or other toxic materials, the number or thickness of the barrier may further depend on legal toxicity guidelines, which may require more or thicker barrier layers. Other considerations for barrier protection include cost, availability, and mechanical strength.

[0322] In some embodiments, the nanostructured film includes two or more barrier layers adjacent to each side of the nanostructured layer, for example, two or three barrier layers on each side, or two barrier layers on each side of the nanostructured layer. In some embodiments, each barrier layer includes a thin glass sheet, for example, a glass sheet with a thickness of about 100 μm, 100 μm or less, or 50 μm or less.

[0323] As will be understood by those skilled in the art, each barrier layer of the nanostructured film of the present invention can have any suitable thickness, depending on the specific requirements and characteristics of the lighting device and application, as well as the individual film components, such as the barrier layer and the nanostructured layer. In some embodiments, each barrier layer can have a thickness of 50 μm or less, 40 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, or 15 μm or less. In some embodiments, the barrier layer comprises an oxide coating, which may comprise materials such as silicon oxide, titanium oxide, and aluminum oxide (e.g., SiO2, Si2O3, TiO2, or Al2O3). The oxide coating can have a thickness of about 10 μm or less, 5 μm or less, 1 μm or less, or 100 nm or less. In some embodiments, the barrier comprises a thin oxide coating with a thickness of about 100 nm or less, 10 nm or less, 5 nm or less, or 3 nm or less. The top and / or bottom barriers may consist of a thin oxide coating, or may include a thin oxide coating and one or more additional material layers.

[0324] Display devices with nanostructured color conversion layers

[0325] In some embodiments, the present invention provides a display device comprising:

[0326] (a) A display panel for emitting a first light;

[0327] (b) a backlight unit configured to provide a first light to the display panel; and

[0328] (c) A color filter (image processing) comprising at least one pixel region, the at least one pixel region comprising a color conversion layer.

[0329] In some embodiments, the color filter (image processing) includes at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 pixel regions. In some embodiments, when blue light is incident on the color filter (image processing), red, white, green, and / or blue light can be emitted through the pixel regions respectively. In some embodiments, the color filter is described in U.S. Patent No. 9,971,076, which is incorporated herein by reference in its entirety.

[0330] In some embodiments, each pixel region includes a color conversion layer. In some embodiments, the color conversion layer includes the nanostructures described herein, configured to convert incident light into light of a first color. In some embodiments, the color conversion layer includes the nanostructures described herein, configured to convert incident light into blue light.

[0331] In some embodiments, the display device includes 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 color conversion layers. In some embodiments, the display device includes one color conversion layer comprising the nanostructures described herein. In some embodiments, the display device includes two color conversion layers comprising the nanostructures described herein. In some embodiments, the display device includes three color conversion layers comprising the nanostructures described herein. In some embodiments, the display device includes four color conversion layers comprising the nanostructures described herein. In some embodiments, the display device includes at least one red conversion layer, at least one green conversion layer, and at least one blue conversion layer.

[0332] In some embodiments, the thickness of the color conversion layer is between about 3 μm and about 10 μm, between about 3 μm and about 8 μm, between about 3 μm and about 6 μm, between about 6 μm and about 10 μm, between about 6 μm and about 8 μm, or between about 8 μm and about 10 μm. In some embodiments, the color conversion layer has a thickness between about 3 μm and about 10 μm.

[0333] The nanostructured color conversion layer can be deposited by any suitable method known in the art, including but not limited to painting, spraying, solvent spraying, wet coating, adhesive coating, spin coating, tape coating, roll coating, flow coating, inkjet printing, photoresist patterning, drop casting, doctor blade coating, fog deposition, or combinations thereof. In some embodiments, the nanostructured color conversion layer is deposited by photoresist patterning. In some embodiments, the nanostructured color conversion layer is deposited by inkjet printing.

[0334] Compositions containing AIGS nanostructures and ligands

[0335] In some embodiments, the AIGS nanostructure composition further comprises one or more ligands. Ligands include amino ligands, polyamino ligands, thiol ligands, phosphine ligands, silane ligands, and polymeric or oligomeric chains, such as polyethylene glycol having amine and silane groups.

[0336] In some embodiments, the amino ligand has Formula I:

[0337]

[0338] in:

[0339] x is from 1 to 100; y is from 0 to 100; and

[0340] R 2 It is C 1-20 alkyl.

[0341] In some embodiments, the polyamino ligand is a polyamino alkane, a polyamino cycloalkane, a polyamino heterocyclic compound, a polyamino-functionalized siloxane, or a polyamino-substituted ethylene glycol. In some embodiments, the polyamino ligand is a C14 compound substituted with two or three amino groups and optionally contains one or two amino groups replacing the carbon group. 2-20 Alkanes or C 2-20Cycloalkanes. In some embodiments, the polyamino ligands are ethylenediamine, 1,2-diaminopropane, 1,2-diamino-2-methylpropane, N-methyl-ethylenediamine, N-ethyl-ethylenediamine, N-isopropyl-ethylenediamine, N-cyclohexyl-ethylenediamine, N-cyclohexyl-ethylenediamine, N-octyl-ethylenediamine, N-decyl-ethylenediamine, N-dodecyl-ethylenediamine, N,N-dimethyl-ethylenediamine, N,N-diethyl-ethylenediamine, N,N'-diethyl-ethylenediamine, N,N'-diisopropyl-ethylenediamine, N,N,N'-trimethyl-ethylenediamine, diethylenetriamine, N-isopropyl-diethylenetriamine, N-(2-aminoethyl)-1,3-propanediamine, triethylenetetramine, N,N'-bis(3-aminopropyl) Ethylenediamine, N,N'-bis(2-aminoethyl)-1,3-propanediamine, tris(2-aminoethyl)amine, tetraethylenepentamine, pentaethylenehexamine, 2-(2-amino-ethylamino)ethanol, N,N-bis(hydroxyethyl)ethylenediamine, N-(hydroxyethyl)diethylenetriamine, N-(hydroxyethyl)triethylenetetramine, piperazine, 1-(2-aminoethyl)piperazine, 4-(2-aminoethyl)morpholine, polyethyleneimine, 1,3-diaminopropane, 1,4-diaminobutane, 1,3-diaminopentane, 1,5-diaminopentane, 2,2-dimethyl-1,3-propanediamine, hexamethylenediamine, 2-methyl-1,5-diaminopropane, 1,7-diaminoheptane, 1,8-diaminooctane, 2,2,4-Dimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 1,9-diaminononane, 1,10-diaminodecane, 1,12-diaminododecane, N-methyl-1,3-propanediamine, N-methyl-1,3-propanediamine, N-isopropyl-1,3-propanediamine, N,N-dimethyl-1,3-propanediamine, N,N'-dimethyl-1,3-propanediamine, N,N'-diethyl-1,3-propanediamine, N,N'-diisopropyl-1,3-propanediamine, N,N,N'-trimethyl-1,3-propanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, N,N'-dimethyl-1,6-hexanediamine, 3,3'-diamino-N-methyl- Dipropylamine, N-(3-aminopropyl)-1,3-propanediamine, spermidine, bis(hexamethylene)triamine, N,N',N”-trimethyl-bis(hexamethylene)triamine, 4-amino-1,8-octanediamine, N,N'-bis(3-aminopropyl)-1,3-propanediamine, spermine, 4,4'-methylenebis(cyclohexylamine), 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3-cyclohexanebis(methylamine), 1,4-cyclohexanebis(methylamine), 1,2-bis(aminoethoxy)ethane, 4,9-dioxa-1,12-dodecanediamine, 4,7,10-trioxa-1,13-tridecanediamine, 1,3-diamino-hydroxy-propane, 4,4-Methylene dipiperidine, 4-(aminomethyl)piperidine, 3-(4-aminobutyl)piperidine, or polyallylamine. In some embodiments, the polyamino ligand is 1,3-cyclohexanebis(methylamine), 2,2-dimethyl-1,3-propanediamine, or tris(2-aminoethyl)amine.

[0342] In some embodiments, the polyamino ligand is a polyamino heterocyclic compound. In some embodiments, the polyamino heterocyclic compound is 2,4-diamino-6-phenyl-1,3,5-triazine, 6-methyl-1,3,5-triazine-2,4-diamine, 2,4-diamino-6-diethylamino-1,3,5-triazine, 2-N,4-N,6-N-tripropyl-1,3,5-triazine-2,4,6-triamine, 2,4-diaminopyrimidine, 2,4,6-triaminopyrimidine, 2,5-diaminopyridine, 2,4,5,6-tetraaminopyrimidine, pyridine-2,4,5-triamine, 1-(3-aminopropyl)imidazole, 4-phenyl-1H-imidazole-1,2 -Diamine, 1H-imidazol-2,5-diamine, 4-phenyl-N(1)-[(E)-phenylmethylene]-1H-imidazol-1,2-diamine, 2-phenyl-1H-imidazol-4,5-diamine, 1H-imidazol-2,4,5-triamine, 1H-pyrrole-2,5-diamine, 1,2,4,5-tetraazine-3,6-diamine, N,N'-dicyclohexyl-1,2,4,5-tetraazine-3,6-diamine, N3-propyl-1H-1,2,4-triazol-3,5-diamine, or N,N'-bis(2-methoxybenzyl)-1H-1,2,4-triazol-3,5-diamine.

[0343] In some embodiments, the polyamino ligand is a polyamino-functionalized siloxane. In some embodiments, the polyamino-functionalized siloxane is one of the following:

[0344]

[0345]

[0346] In some embodiments, the polyamino ligand is a polyamino-substituted ethylene glycol. In some embodiments, the polyamino-substituted ethylene glycol is 2-[3-amino-4-[2-[2-amino-4-(2-hydroxyethyl)phenoxy]ethoxy]phenyl]ethanol, 1,5-diamino-3-oxapentane, 1,8-diamino-3,6-dioxaoctane, bis[5-chloro-1H-indol-2-yl-carbonyl-aminoethyl]-ethylene glycol, amino-PEG8-t-Boc-hydrazide, or 2-(2-(2-ethoxyethoxy)ethoxy)ethylamine.

[0347] In some embodiments, the thiol ligand is (3-mercaptopropyl)triethoxysilane, 3,6-dioxa-1,8-octanedithiol; 6-mercapto-1-hexanol; thiosuccinic acid, thioundecanoic acid, thiohexanoic acid, thiopropionic acid, thioacetic acid, cysteine, methionine, and thiol poly(ethylene glycol).

[0348] In some embodiments, the silane ligand is an aminoalkyltrialkoxysilane or a thioalkyltrialkoxysilane. In some embodiments, the aminoalkyltrialkoxysilane is 3-aminopropyl)triethoxysilane or 3-mercaptopropyl)triethoxysilane.

[0349] In some embodiments, the ligands include, but are not limited to, aminopolyoxyalkylene oxide (e.g., about mw1000); (3-aminopropyl)trimethoxysilane; (3-mercaptopropyl)triethoxysilane; DL-α-lipoic acid; 3,6-dioxa-1,8-octanedithiol; 6-mercapto-1-hexanol; methoxypolyethylene glycolamine (about mw500); poly(ethylene glycol) methyl ether thiol (about mw800); diethylphenyl phosphite; bibenzyl N,N-diisopropylphosphite; di-tert-butyl N,N-diisopropylphosphite; tris(2-carboxyethyl)phosphine hydrochloride; poly(ethylene glycol) methyl ether thiol (about mw2000); methoxypolyethylene glycolamine (about mw750); acrylamide; and polyethyleneimine.

[0350] Specific combinations of ligands include: amino-polyalkylene oxide (approx. mw1000) and methoxy polyethylene glycolamine (approx. mw500); amino-polyalkylene oxide (approx. mw1000) and 6-mercapto-1-hexanol; amino-polyalkylene oxide (approx. mw1000) and (3-mercaptopropyl)triethoxysilane; and 6-mercapto-1-hexanol and methoxy polyethylene glycolamine (approx. mw500); which provide excellent dispersibility and thermal stability. See Example 9.

[0351] Compared to AIGS-containing films without polyamino ligands, films containing both AIGS nanostructures and polyamino ligands exhibit higher film conversion efficiency (PCE), less wrinkling, and less film delamination compared to films containing only ethyl or monoamino ligands. Therefore, compositions containing AIGS-polyamino ligands are uniquely suitable for nanostructured color conversion layers.

[0352] The following examples are illustrative and not limiting examples of the products and methods described herein. Given this disclosure, suitable modifications and adjustments to various conditions, formulations, and other parameters commonly encountered in the art and readily apparent to those skilled in the art are within the spirit and scope of this invention.

[0353] Example

[0354] Example 1: AIGS nucleosynthesis

[0355] Sample ID 1 was prepared using the following typical AIGS nucleosynthesis method: 0.06 M CH3CO2Ag in 4 mL oleylamine, 0.2 M InCl3 in 1 mL ethanol, 0.95 M sulfur in 1 mL oleylamine, and 0.5 mL dodecyl mercaptan were injected into a flask containing 5 mL degassed octadecene, 300 mg trioctylphosphine oxide, and 170 mg gallium acetylacetonate. The mixture was heated to 40 °C for 5 minutes, then the temperature was increased to 210 °C and held for 100 minutes. After cooling to 180 °C, 5 mL of trioctylphosphine was added. The reaction mixture was transferred to a glove box and diluted with 5 mL toluene. The final AIGS product was precipitated by adding 75 mL of ethanol, centrifuged, and redispersed in toluene. Samples ID 2 and 3 were also prepared using this method. The optical properties of the AIGS nuclei were measured and summarized in Table 2. The size and morphology of the AIGS nuclei were characterized by transmission electron microscopy (TEM).

[0356] Table 2

[0357]

[0358] Example 2: AIGS nanostructures with ion exchange treatment

[0359] Sample ID 4 was prepared using the following typical ion exchange treatment: 2 mL of a 0.3 M gallium oleate solution in octadecane and 12 mL of oleylamine were introduced into a flask and degassed. The mixture was heated to 270 °C. 1 mL of a 0.95 M sulfur solution in oleylamine and 1 mL of a premixed solution of separated AIGS cores (15 mg / mL) were co-injected. The reaction was stopped after 30 min. The final product was transferred to a glove box, washed with toluene / ethanol, centrifuged, and redispersed in toluene. Samples ID 4–8 were also prepared using this method. The optical properties of the resulting AIGS nanostructures are summarized in Table 3. Ion exchange with gallium ions resulted in almost complete band-edge emission. An increase in average particle size was observed by TEM.

[0360] Table 3

[0361]

[0362] Example 3: Gallium halide and trioctylphosphine ion exchange treatment

[0363] The room-temperature ion-exchange reaction with the AIGS nanostructure was carried out as follows: a GaI3 solution (0.01–0.25 M) in trioctylphosphine was added to the AIGS QD and held at room temperature for 20 hours. This treatment resulted in a significant enhancement of band-edge emission, as summarized in Table 4, while essentially maintaining the peak wavelength (PWL).

[0364] Compositional changes before and after GaI3 addition were monitored using inductively coupled plasma atomic emission spectroscopy (ICP-AES) and energy-dispersive X-ray spectroscopy (EDS), as summarized in Table 4. Composite images of In and Ga elemental distributions before and after GaI3 / TOP treatment show a radial distribution from In to Ga, indicating that the ion exchange treatment resulted in a gradient of a larger amount of gallium near the surface of the nanostructure and a smaller amount of gallium at the center.

[0365] Table 4

[0366]

[0367] Example 4: AIGS ion exchange treatment using an oxygen-free Ga source

[0368] Samples IDs 14 and 15 were prepared using the following typical treatment of AIGS nanoparticles with an oxygen-free Ga source: 400 mg GaI3 dissolved in 400 μL toluene was added to 8 mL of degassed oleylamine, followed by 40 mg of AIGS core, and then 0.95 M sulfur in 1.7 mL of oleylamine. The reaction was heated to 240 °C, held for 2 hours, and then cooled. The final product was transferred to a glove box, washed with toluene / ethanol, centrifuged, and dispersed in toluene. Samples IDs 15 and 16 were also prepared using this method. Samples IDs 11-13 were prepared using the method of Example 2. The optical properties of the treated AIGS materials are shown in Table 5.

[0369] Table 5

[0370]

[0371] As shown in Table 5, when oleylamine is used as a solvent, the quantum yield of the treated AIGS nanostructures can be improved by using Ga(III) chloride instead of Ga(III) acetylacetone or gallium oleate. The final material subjected to ion exchange using gallium(III) chloride exhibits similar size and similar band-edge to trap emission properties to the starting nanostructure. Therefore, the increase in quantum yield (QY) is not solely due to an increase in the trap emission component. Furthermore, unexpectedly, it was found that when Ga(III) iodide was used instead of Ga(III) chloride, the AIGS nanostructures appeared to dissolve in the reaction mixture, and ion exchange did not occur.

[0372] High-resolution TEM with energy-dispersive X-ray spectroscopy (EDS) of sample 14 revealed that the nanostructure may contain a slight gradient of lower In from the center to the surface of the AIGS nanostructure. This suggests that the treatment under these conditions was caused by a process in which In was exchanged from the AIGS structure and replaced by Ga, while Ag was present throughout the structure rather than growing distinct GS layers. This could also contribute to improved quantum yield of the nanostructure due to the smaller strain.

[0373] Example 5: Thermally injected AlGS core from a pre-formed Ag2S nanostructure mixed with a pre-formed In-Ga reagent

[0374] To prepare Ag₂S nanostructures, 0.5 g AgI and 2 mL oleylamine were added to a 20 mL vial under a N₂ atmosphere and stirred at 58 °C until a clear solution was obtained. In a separate 20 mL vial, 5 mL DDT and 9 mL of 0.95 M sulfur in oleylamine were mixed. The DDT+S-OYA mixture was added to the AgI solution and stirred at 58 °C for 10 min. The obtained Ag₂S nanoparticles were used without washing.

[0375] To prepare the In-Ga reagent mixture, 1.2 g Ga (acetylacetonate)3, 0.35 g InCl3, 2.5 mL oleylamine, and 2.5 mL ODE were charged into a 100 mL flask. The mixture was heated to 210 °C under a N2 atmosphere and maintained for 10 minutes. An orange and viscous product was obtained.

[0376] To form AIGS nanoparticles, 1.75 g TOPO, 23 mL oleylamine, and 25 mL ODE were added to a 250 mL flask under N2. After degassing under vacuum, the solvent mixture was heated to 210 °C over a period of 40 minutes. In a 40 mL vial, the Ag2S and In-Ga reagent mixture from above was mixed at 58 °C and transferred to a syringe. The Ag-In-Ga mixture was then injected into the solvent mixture at 210 °C and held for 3 hours. After cooling to 180 °C, 5 mL of trioctylphosphine was added. The reaction mixture was transferred to a glove box and diluted with 50 mL toluene. The final product was precipitated by adding 150 mL ethanol, centrifuged, and redispersed in toluene. The AIGS nanostructures were then ion-exchanged using the method described in Example 4. Table 6 shows the optical properties of the materials prepared by this method at scales up to 24 times larger than those described above.

[0377] Table 6

[0378]

[0379] Example 7: Repeated gallium ion exchange improves the photoluminescence stability of AIGS nanostructures

[0380] 7.1 First Ion Exchange Process

[0381] Oleylamine (OYA, 2.5 L) was degassed under vacuum at 40 °C for 40 min. AIGS nanostructures (25.4 g, in toluene) were added, followed by GaCl3 (127 g, in minimal toluene) and sulfur dissolved in OYA (0.95 M, 570 mL). The mixture was heated to 240 °C for 40 min and maintained for 4 h. After cooling, the mixture was diluted with 1 volume of toluene. After centrifugation to remove some byproducts, the material was washed with 2 volumes of ethanol, collected by centrifugation, and redissolved in toluene. After a second wash, the nanostructures were dissolved in heptane for storage.

[0382] 7.2 Second Ion Exchange Process

[0383] Oleylamine (OYA, 960 mL) was degassed under vacuum at 40 °C for 20 minutes. Ion-exchanged nanostructures of AIGS, for example from Example 7.1 (12 g, in heptane), were added to OYA, followed by GaCl3 (22.5 g, in a minimum volume of toluene), and then sulfur dissolved in OYA (0.95 M, 100 mL). The mixture was heated to 240 °C over 40 minutes and held for 3 hours. After cooling, the mixture was diluted with 1 volume of toluene, washed (precipitated with 1.6 volumes of ethanol, centrifuged), and redispersed in toluene or heptane as needed. Further ethanol washing was applied when ligand exchange was performed on the ink formulation, and the QD was redispersed in heptane.

[0384] 7.3 Alternative Second Ion Exchange Process

[0385] Oleylamine (15 mL) was degassed under vacuum at 60 °C for 20 minutes. GaCl3 (360 mg in a minimum volume of toluene) was added to OYA, followed by AIGS, such as the AIGS from Example 7.1 (200 mg in heptane), and then sulfur dissolved in OYA (0.95 M, 1.6 mL). The mixture was heated to 240 °C over a period of 40 minutes and held for 3 hours. After cooling, the mixture was washed as described in Example 7.1.

[0386] 7.4 Alternative Second Ion Exchange Process

[0387] This embodiment is performed as described in Example 7.3, but on a 3x scale.

[0388] 7.5 Substituted Second Ion Exchange Process

[0389] Oleylamine (10 mL) and oleic acid (5 mL) were degassed under vacuum at 90 °C for 20 minutes. (Ga(NMe3)3)2 (206 mg) and GaCl3 (180 mg in a minimum volume of toluene) were added, followed by the addition of AIGS, such as AIGS from Example 7.1 (200 mg in heptane). After heating to 130 °C, TMS2S (a 50% solution in 0.65 mL of ODE) was added over 20 minutes, and the mixture was held for 2.5 hours. After cooling, the mixture was washed as described in Example 7.1.

[0390] 7.6 Results

[0391] AIGS nanostructures were subjected to an ion-exchange process, where In was exchanged for Ga. The higher temperature used in this process (240 °C vs. 210 °C) compared to nucleus growth resulted in ripening, thus producing a larger average size than the untreated nanostructures. The nanostructures lacked a well-differentiated shell structure, which was observed in cross-sectional TEM elemental mapping. The absence of a high-bandgap shell is expected to limit the retention of photoluminescence in these materials during film processing.

[0392] After the second ion exchange process, the average TEM size did not increase. Figure 2A-2C However, TEM element mapping shows that a more pronounced gradient has developed into the Ga-rich (higher bandgap) region in QD.

[0393] The elemental composition of single and multiple ion exchange processes is shown in Table 7. The values ​​are averages from 10-20 samples from Examples 7.1 and 7.2.

[0394] Table 7

[0395]

[0396] The properties of the ion-exchanged AIGS nanostructures are shown in Table 8. The metal ratios are molar ratios determined by ICP.

[0397] Table 8

[0398] Sample ID PWL,nm FWHM,nm BE,% QY,% Ag / (Ag+In+Ga) In / (In+Ga) Example 7.1 524.2 34.8 90 83 0.41 0.27 Example 7.2 523.6 34.4 90 89 0.40 0.24 Example 7.3 525.1 34.4 90 87 0.42 0.23 Example 7.4 525.9 34.3 90 88 0.42 0.24 Example 7.5 524.4 33.5 90 62 0.28 0.12 Example 7.6 521.0 24.5 92 89 0.41 0.18

[0399] The second ion exchange process significantly improved the PCE of the film retained after UV curing and baking at 180°C, as shown in Table 9. This is attributed to the process of increasing the Ga concentration in the outer layer of the nanostructure, resulting in a gradient to the higher bandgap region introduced through ion exchange.

[0400] Table 9

[0401]

[0402] Example 8 - Compositions comprising AIGS nanostructures and polyamino ligands

[0403] abbreviation

[0404] ●·Jeffamine–Jeffamine M-1000

[0405] ●·HDDA-1-6 Hexanediol Diacrylate

[0406] ●·Bismethylamine-1,3-cyclohexanedimethylamine

[0407] ●·PCE - Photon Conversion Efficiency

[0408] The crude AIGS QD growth solution was purified by washing with ethanol and redispersing in heptane (solution 1). 6-Mercapto-1-hexanol was added to solution 1, heated at 50°C for 30 minutes, washed with ethanol, and redispersed in heptane (solution 2). 2 μL of 6-mercapto-1-hexanol was added per 100 mg of QD inorganic solids. Jeffamine and HDDA for the ligand exchange phase were added to solution 2, heated at 80°C for 1 hour, precipitated in heptane, and redispersed in HDDA (solution 3). 83 mg of Jeffamine and 0.42 g of HDDA were added per 100 mg of QD inorganic solids. Solution 3 and HDDA were added to an inkjet ink composition containing 10 wt% TiO2 and 90 wt% monomers. The inkjet formulation comprises 10 wt% QD inorganic mass, 4 wt% TiO2, and the remaining 86 wt% is a combination of the following: ligands (bound and unbound), HDDA, monomers, photoinitiators, and other confounding organic residues from the QD solution. This ink formulation is solution 4.

[0409] Add polyamino ligand dimethylamine (50 mg dimethylamine / 100 mg QD inorganic solid) to solution 4, and then cast the composition into a film.

[0410] film casting

[0411] Solution 4 was spin-coated onto a 2”×2” glass substrate. The film was cured using a UV LED curing lamp. The film's power conversion efficiency (PCE) and luminance were then measured. The film was then baked for 30 minutes with the heat plate set at 180°C, slightly above the plate. Alternatively, the film was baked for 10 minutes with the heat plate set at 180°C in direct contact with the plate surface.

[0412] Then, the film's PCE was tested. A 1”×1” masked array of blue 448nm LEDs provided the excitation source for the film. An integrating sphere was placed on top of the film and connected to a fluorometer. See [link to documentation]. Figure 3A and 3B The collected spectra were analyzed to obtain PCE.

[0413] PCE is the ratio of the number of forward-emission green photons to the number of blue photons generated by the test platform. While the emission spectrum from 484 nm to 700 nm was used to calculate PCE, green emission is expected to have a peak wavelength between 484 nm and 545 nm, with the majority of emission below 588 nm. PCE, LRR, and film morphology are reported in Table 10. Unexpectedly, the presence of ligands 1,3-cyclohexanebis(methylamine), tris(2-aminoethyl)amine, and 2,2-dimethyl-1,3-propanediamine resulted in high PCE retention, high LRR, and no wrinkling after baking at 180 °C, compared to films without ligands.

[0414] Table 10

[0415]

[0416] Figure 1 This shows the effect of diamine addition on membrane morphology. Figure 1 The membranes in the image, from left to right, contain: no additive (wrinkled); 2,2-dimethyl-1,3-propanediamine (diamine, no wrinkling); cyclohexanemethylamine (monoamine, wrinkled); and tris(2-aminoethyl)amine (triamine, no wrinkling). From left to right, the first and third membranes, which do not contain diamines, exhibit extensive wrinkling. Conversely, the second and fourth membranes do not exhibit wrinkling. Unexpectedly, the use of diamino ligands in AIGS membranes resulted in a significant reduction in membrane wrinkling.

[0417] Example 9 - Testing of additional ligands for AIGS nanostructures

[0418] In this experiment, the enhanced QY, high compatibility, and good thermal stability of other ligands used for AIGS nanoparticles were tested. Furthermore, the protection of AIGS nanostructures from degradation and oxidation by these ligands was evaluated. Combinations of ligands that can be formulated into AIGS ink compositions were also tested.

[0419] Ligand exchange with these ligands is carried out in organic solvents such as ethyl acetate, PGMEA, acetone, xylene, 1,2-dichlorobenzene (ODCB), butyl acetate, and diethylene glycol monoethyl ether (DGMEE).

[0420] AIGS nanostructures undergo ligand exchange with ligands containing polymeric or oligomeric chains, such as polyethylene glycol with amine and silane groups, and soft bases for co-passivation, such as phosphino-, mercapto-, and combinations thereof.

[0421] Figure 4 Quantum yield values ​​for numerous individual ligands and AIGS nanostructures subjected to a single ion exchange treatment as described herein are depicted. In this figure, NG: native AIGS; NG-NL1: amino-polyalkylene oxide, approximately mw 1000; NG-NL2: (3-aminopropyl)trimethoxysilane; NG-NL3: (3-mercaptopropyl)triethoxysilane; NG-NL4: DL-α-lipoic acid; NG-NL5: 3,6-dioxa-1,8-octanedithiol; NG-NL6: 6-mercapto-1-hexanol; NG-NL7: methoxypolyethylene glycolamine 500; NG-NL8: poly(ethylene glycol) methyl ether thiol Mn 800; NG-NL9: diethylphenyl phosphite; NG-NL10: dibenzyl N,N-diisopropylphosphite; NG-NL11: di-tert-butyl N,N-diisopropylphosphite; NG-NL12: tris(2-carboxyethyl)phosphine hydrochloride; NG-NL13: poly(ethylene glycol) methyl ether thiol Mn 2000; NG-NL14: methoxy polyethylene glycol amine 750; NG-NL15: acrylamide; and NG-NL16: polyethyleneimine).

[0422] like Figure 4 As shown, treatment of AIGS nanostructures with 3-mercaptopropyltriethoxysilane (NL3), 3,6-dioxa-1,8-octanedithiol (NL5), and 6-mercapto-1-hexanol (NL6) resulted in high QY (73.7%, 72.9%, and 76.1%, respectively). Therefore, the present invention provides AIGS nanostructure compositions comprising at least one thiol-substituted ligand that provides improved QY. It is believed that thiol-substituted ligands provide high QY by passivating the surface of the AIGS nanostructures and reducing defect emission. Amino-substituted ligands also improve QY.

[0423] In this single-ligand experiment, the polyethylene glycolamine-substituted ligands (L1, L7, L8, and L13), thiol-substituted ligands (L3, L5, and L6), and silane ligand (L2) exhibited better quality and responsiveness (QY) compared to the natural AIGS nanostructure. Furthermore, ligands L1, L7, and L8 provided better compatibility with the monomer when dispersed in HDDA.

[0424] Figure 5This is a graph showing the QY% of various 2-ligand combinations that provide improved QY% (good combinations) and reduced QY% (bad combinations). Surface defects can be reduced by adding thiol ligands. The combination of L6 and L7 provides better stability than other combinations. However, for relatively hydrophilic ink compositions, better ligands are relatively hydrophilic ligands, such as methoxy polyethylene glycolamine and poly(ethylene glycol) methyl ether thiol. This thiol also improves QY by passivating surface defects.

[0425] The suitable temperature for ligand exchange is from room temperature to 120°C. The total amount of ligands in the composition can be 60% to 150% of the mass of AIGS.

[0426] Table 11 shows the relative changes in QY, PWL, and FWHM before and after ligand exchange with multiple ligands. Table 11 shows that L6 and L7 are the most effective ligand combinations for ink formulations, especially when combined with acrylate monomers. Combinations L2 and L7, L2 and L6, and L2 and L3, L6 and L7 provide excellent dispersibility and thermal stability. See also Figure 6 .

[0427] Table 11

[0428]

[0429] Further investigation was conducted on ligand combinations that provided good thermal stability when heated to 180°C for 30 minutes in a glove box. Ligand combinations L6 and L7, L2 and L6, and L2 and L3 provided better stability than the single ligand L1. See [link to relevant documentation] Figure 6 .

[0430] The effect of different ligand combinations on QY was also investigated. The weight ratio of the ligands was varied while the total amount of ligands remained constant. Optimal QY was achieved with an L6:L7 ratio of 7:3. (See also...) Figure 7 Compared to natural AIGS nanostructures, all combinations with L6 and L7 exhibited enhanced QY, except for the 9:1 ratio. While this mixture exhibited high QY, it was difficult to purify because no precipitation occurred. Mixtures of L6 and L2, L3 and L7, and L5 and L7 are good ligand mixtures for AIGS nanostructures. These ligand combinations can be used with a variety of monomers such as tetrahydrofurfuryl acrylate, tris(propylene glycol) diacrylate, 1,4-bis(acryloyloxy)butane, diethylene glycol ethyl ether acrylate, isobornyl acrylate, hydroxypropyl acrylate, 2-(acryloyloxy)ethyl hydrogen succinate, and 1,6-hexanediol diacrylate.

[0431] Example 10 - Improvement of PCE in AIGS Membrane

[0432] In a N2-filled glove box, AIGS QD coated with appropriate ligands is mixed into an ink containing one or more monomers, TiO2 scattering particles, and a photoinitiator. A film is cast by spin-coating these inks and then cured using UV irradiation. The film is then baked on a hot plate at 180°C for 30 minutes to remove any residual volatile components. All these processes are carried out in an inert atmosphere (in a N2-filled glove box).

[0433] Typically, in this stage, the film is measured in air by placing it face up over a blue LED light source. An integrating sphere connected to a spectrophotometer is placed on top of the QD film (see Figures 3a and 3B), and the film's emission spectrum is captured. This measurement is repeated with a blank glass substrate (without QD). The blue light absorption and photon conversion efficiency (PCE) of the QD film are measured using the following formula:

[0434] Blue light absorption = Number of blue photons transmitted through the QD film / Number of incident blue photons

[0435] PCE = #Number of forward-emitted green photons (484-588nm) / Number of incident blue photons

[0436] To investigate the effects of air and moisture during measurement, the baked QD membrane was sealed before being removed from the N2 glove box. This was accomplished by applying a few drops of UV-curable transparent adhesive to the QD layer, then placing a glass coverslip and curing the adhesive by UV irradiation. The QD membrane thus sealed with glass and adhesive was measured in air using the method described above.

[0437] The results indicate that encapsulating the QD film before air measurement is crucial for achieving high photon conversion efficiency (PCE). Table 12 shows the results for a group of films measured with and without encapsulation. For comparison, PCE values ​​from a typical QDCC film containing InP QD are also shown. When encapsulated and measured, the film containing the AIGS nanostructure exhibits a higher post-baking PCE value than InP at a much lower QD load. Further improvements in PCE were achieved by irradiating the film with a blue light source (~6 mW / cm²) for 1 hour. Furthermore, the QDCC film made with AlGS QD exhibits a much narrower emission (FWHM ~30 nm) compared to the film made with InP QD (FWHM 36 nm). This is due to the lower FWHM of the AIGS QD in solution (34 nm vs. 39 nm), combined with the use of mono- and poly-amino ligands that allow for good dispersion in the ink resin.

[0438] Table 12

[0439]

[0440]

[0441] Figure 8 The effects of encapsulation and blue light treatment were shown on a much wider range of samples. Unexpectedly, the PCE values ​​achieved through encapsulation (greater than 32%) were significantly higher than those without encapsulation.

[0442] Figure 9 The emission linewidth (FWHM) of the film is shown after the 180°C baking step and subsequent encapsulation. The median FWHM of the film baked at 180°C is 30.5 nm, which narrows further to 30.1 nm after encapsulation. This narrowing may be a result of film brightening during encapsulation.

[0443] Although the samples in this study were encapsulated using glass and adhesives, this improvement in PCE can be achieved by any method capable of forming an oxygen barrier layer on the QD layer. In the mass production of devices containing these QDCC layers, encapsulation may be performed using a vapor deposition process. In this case, a typical process flow would involve inkjet printing of the QD layer, followed by UV curing, baking at 180°C to remove volatiles, deposition of an organic planarization layer, and then deposition of an inorganic barrier layer. Techniques used for depositing the inorganic layer can include atomic layer deposition (ALD), molecular layer deposition (MLD), chemical vapor deposition (CVD) (with or without plasma enhancement), pulsed vapor deposition (PVD), sputtering, or metal evaporation. Other potential encapsulation methods include solution-processed or printed organic layers, UV or thermosetting adhesives, lamination using barrier films, etc.

[0444] Example 11 - AIGS ink containing monomers incorporated into ligands coated on AIGS surfaces

[0445] Compared to LE performed purely in solvent, ligand exchange (LE) of AIGS nanostructures in the presence of monomers resulted in higher solution QY, better ink compatibility, and better membrane performance. This was demonstrated through LE and membrane evaluations using 16 different media.

[0446] The LE of quantum dots (QDs) such as CdSe and InP can be carried out in organic solvents to replace the natural ligands with the desired ligands. The resulting QDs can then be formulated into solvent-free inks by dispersing the QDs in monomers, removing the original solvent, and adding other ink components such as scattering media and photoinitiators.

[0447] This method can also be used for LE of AIGS nanostructures, exhibiting high QY retention. However, this method typically results in poor dispersibility of the nanostructures in the monomer after solvent removal. Good dispersibility of AIGS nanostructures in ink, and effective passivation of the nanostructure surface by ligands, are essential for maintaining film performance under harsh processing conditions such as UV irradiation and high-temperature baking. Therefore, AIGS nanostructures with ligand exchange using conventional methods are not suitable for QDCC applications.

[0448] Figure 10 PLQY displays the following AIGS nanostructures, which underwent ligand exchange in various organic solvents such as acetone, PGMEA, ethyl acetate, toluene, dichloromethane (DCM), chloroform, dimethylformamide (DMF), and ethanol at two temperatures (room temperature (25°C) and 80°C). Jeffamine M1000 was used as the ligand at a mass ratio of 0.8:1 to the AIGS nanostructures.

[0449] Several solvents (PGMEA, ethyl acetate, toluene, and DCM) are very effective in maintaining QY after LE. Notably, LE at room temperature results in a higher QY than LE at 80°C. Other solvents tested (such as acetone, chloroform, DMF, and ethanol) result in lower QY.

[0450] However, as shown in Table 13 (o = clear dispersion; Δ = turbid dispersion), ligand-exchanged AIGS nanostructures in solvent at room temperature exhibit poor compatibility with HDDA (a monomer commonly used in inkjet printing inks). Ligand-exchanged AIGS nanostructures at 80°C show better compatibility with HDDA, but with lower QY. Therefore, it is difficult to find effective LE conditions that result in high QY and good compatibility with HDDA.

[0451] Table 13

[0452]

[0453] The LE studies were repeated using a range of common monomers (as shown in Table 14) instead of organic solvents. The LE was performed by mixing the starting AIGS nanostructures (in heptane) with the monomers, followed by the addition of Jeffamine Ml000 and heating at 80 °C.

[0454] Table 14

[0455]

[0456]

[0457] Figure 11The QY is shown after LE in the presence of the monomer. In all 16 cases, QY increases with LE and is also higher than the QY achieved by LE in an organic solvent.

[0458] Following LE, the AIGS nanostructures were separated and purified by precipitation in heptane, and the yield was calculated by recording the initial and final QD masses. Unlike LE in solvent (where only small mass changes were observed), the mass of QDs with ligand exchange in monomers increased by 30–100%, depending on the monomer. Since most of the monomers tested are miscible with heptane and will be removed during QD precipitation, this indicates that a certain amount of monomer is incorporated into the ligands coated on the QD surface.

[0459] All 16 AIGS samples were dispersed in HDDA and then mixed into an ink containing a scattering medium and a photoinitiator. Unlike nanostructures with ligand exchange in solvents, all 16 samples tested here showed good compatibility in HDDA. Three films were cast from each ink stream by spin coating at 700, 800, and 900 rpm and then cured by UV irradiation.

[0460] like Figure 12 As shown, some monomers M2, M3, M4, M5, M6 and M8 exhibit high membrane EQE and can be good LE media for AIGSQD.

[0461] Figure 13 The blue light absorption of AIGS nanostructured films spin-coated at 800 RPM is shown. M7, M10, M13, M15, and M16 provide very high blue light absorption.

[0462] Example 12: Enhancing Blue Light Absorption with Polyamino Ligands

[0463] Typical film deposition processes involve a hard bake at very high temperatures (typically around 200°C) to completely remove any residual solvents and volatile components. This hard bake prevents outgassing during the deposition of other layers on top of the QDCC layer. This harsh baking sometimes results in very low EQE. Furthermore, either the nanostructure is damaged by the high temperature, or ligands detach from the nanostructure, leading to aggregation. Table 15 shows the typical AIGS film EQE after UV curing and after a 180°C hard bake. Even with a good EQE, above 33% after UV curing, the EQE drops below 19% after hard baking at 180°C for 30 minutes. The light retention ratio (LRR), the ratio of EQE after baking to EQE before baking, is very low, below 60%, meaning that film performance decreases by more than 40% after baking.

[0464] Table 15

[0465] UV after After baking LRR Membrane #1 33.7％ 18.4％ 54.7％ Membrane #2 33.1％ 18.3％ 55.3％

[0466] To overcome the high EQE loss and resulting low LRR during hard baking, two methods were tested to improve LRR.

[0467] To maintain the uniform dispersion of the AIGS nanostructure throughout the film and prevent aggregation, a diamine (1,3-bis(aminomethyl)cyclohexane) is added to the AIGS monomer dispersion before ink formulation. Alternatively, it can be added to the ink formulation after mixing it with other ink components (such as scattering media and photoinitiators) in the AIGS monomer dispersion. Figure 14 As observed, adding diamine to the AIGS-monomer dispersion before ink formulation increased the EQE after UV curing and POB. When diamine was added at 5% w / w of the inorganic mass of AIGS, the EQE after UV curing increased by 3%. Adding more diamine did not further improve EQE. After POB, the effect of diamine on improving EQE was even greater. Compared with no monomer in the diamine, the EQE was increased by 5% with the addition of 5% diamine. With the addition of 30% diamine, the EQE increased from 25% to 32% and the LRR was 92%, which is similar to the results observed by InP green QD film. The side effect of diamine is an increase in viscosity, such as... Figure 15 As seen in the text. However, for monomers such as ethyl acrylate, the ink viscosity decreases significantly to below 20 cP at room temperature.

[0468] As an alternative to increasing EQE, better AIGS surface passivation was attempted using diamines. For example... Figure 16 As shown, the QY of AIGS nanostructures undergoing ligand exchange in the presence of diamine is increased by more than 12% immediately after LE. It should be noted that the QY of the AIGS nanostructures is also enhanced after heat treatment (simulating hard baking) at 180°C for 30 minutes in the presence of monomer. For LE, the decrease in QY after 30 minutes at 180°C becomes smaller with increasing diamine content. When the diamine in LE is 50% w / w, the QY before and after heat treatment is almost equal, and when 70% diamine is used in LE, the QY after heat treatment becomes higher.

[0469] The performance of QDCC films using these AIGS nanostructures was plotted on Figure 17The membrane EQE is better when diamine is used in the LE compared to when no diamine is used, and this enhancement increases even further with the addition of more diamine, up to 50%. The EQE obtained by adding 70% diamine and LE is lower than 30% and 50%, respectively. It is suspected that when higher amounts of diamine are used in the LE, the amount of diamine incorporated into the AIGS surface increases, but this reduces the amount of ligands and / or monomers on the AIGS surface. The reduction in QD quality observed after using LE with diamine is likely a result of fewer ligands and / or monomers on the QD surface. This also occurs when diamine is added to the monomers for use in the LE, which leads to an increase in ink viscosity.

[0470] When these two methods are used to improve membrane EQE, such as Figure 19 As shown, the effect of diamine on membrane EQE is highest when added to both the ligand exchanger and monomer dispersion. Viscosity does not necessarily depend on the total amount of diamine in the ink. The sample with the highest diamine content (where diamine is used in both the LE and monomer dispersion) has a medium viscosity. This viscosity is lower than that of the sample using the same amount of diamine only in the LE.

[0471] The enhancement of EQE using diamines in LE and / or monomer dispersions was tested using 1,3-bis(aminomethyl)cyclohexane and five other additives listed in Table 16. All additives had similar effects on the initial EQE, and A1, A5, and A6 were slightly better than the others when added directly with the monomer. However, after hard baking, A1 and A6 were the two best additives in terms of the final film EQE. Furthermore, among the listed amines, good EQE was obtained without using the same additives added to the LE and monomer. Even when the same diamine is used in the addition of LE and diamine, the effect on improving EQE can vary. For example, as... Figure 23 As shown, when used in monomer addition, A6 retains EQE as effectively as Al, but it is not as effective as Al when used in LE.

[0472] Table 16

[0473]

[0474] While various embodiments have been described above, it should be understood that they are presented by way of example only and not by way of limitation. It will be apparent to those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope should not be limited by any of the exemplary embodiments described above, but should be defined solely by the appended claims and their equivalents.

[0475] All publications, patents and patent applications mentioned in this specification represent the skill of a person skilled in the art to which this invention pertains, and are incorporated herein by reference to the extent that each individual publication, patent or patent application is specifically and individually indicated to be incorporated herein by reference.

Claims

1. A film comprising an Ag-In-Ga-S (AIGS) nanostructure and at least one ligand, wherein the at least one ligand is coated on the surface of the AIGS nanostructure and exhibits a photon conversion efficiency (PCE) greater than 32% at a peak emission wavelength of 480-545 nm when excited by a blue light source with a wavelength of 450 nm, wherein the film further comprises at least one organic resin, and the at least one organic resin is cured. At least one of which satisfies (1) and (2): (1) The AIGS nanostructure is prepared by a method comprising: reacting the AIGS core with gallium chloride to exchange ions with gallium. (2) The AIGS nanostructure comprises a gradient of gallium increasing from the surface of the nanostructure to decreasing at the center of the nanostructure. The nanostructure described above has an emission spectrum with a full width at half maximum (FWHM) of less than 40 nm. The nanostructures described herein possess a quantum yield (QY) of 80-99.9%. The nanostructure described herein has an OD of 0.8 or greater. 450 / mass (mLmg) -1 cm -1 ), At least 80% of the aforementioned emissions are edge-fired, and The at least one of the ligands is a polyamino ligand.

2. The membrane according to claim 1, wherein the nanostructure has an emission spectrum with an FWHM of 24-38 nm.

3. The membrane according to claim 1, wherein the nanostructure has an emission spectrum with an FWHM of 27-32 nm.

4. The membrane according to claim 1, wherein the nanostructure has an emission spectrum with an FWHM of 29-38 nm.

5. The membrane according to claim 1, wherein the nanostructure has 85-95% QY.

6. The membrane according to claim 1, wherein the nanostructure has a QY of 86-94%.

7. The membrane according to claim 1, wherein the OD of the nanostructure 450 / mass (mL mg) -1 cm -1 (The range is 0.8-2.5, including the endpoints.) 8. The membrane according to claim 1, wherein the OD of the nanostructure 450 / mass (L mg) -1 cm -1 (Including the endpoints) within the range of 0.87-1.

9.

9. The membrane according to claim 1, wherein the average diameter of the nanostructures by means of TEM is less than 10 nm.

10. The membrane according to claim 9, wherein the average diameter is 5 nm.

11. The membrane of claim 1, wherein at least 90% of the emission is edge emission.

12. The membrane according to claim 1, wherein 92% to 98% of the emission is edge emission.

13. The membrane according to claim 1, wherein 93% to 96% of the emission is edge emission.

14. The membrane according to claim 1, wherein the at least one polyamino ligand is a polyamino alkane, a polyamino cycloalkane, a polyamino heterocyclic compound, a polyamino-functionalized organosilicon, or a polyamino-substituted ethylene glycol.

15. The membrane according to claim 1, wherein the polyamino ligand is a C14 ligand substituted with two or three amino groups and optionally contains one or two amino groups replacing carbon groups. 2-20 Alkanes or C 2-20 Cycloalkanes.

16. The membrane according to claim 15, wherein the polyamino ligand is 1,3-cyclohexanebis(methylamine), 2,2-dimethyl-1,3-propanediamine, tris(2-aminoethyl)amine, or 2-methyl-1,5-diaminopentane.

17. The membrane according to claim 1, wherein the membrane is 5-15 μm thick.

18. The membrane of claim 1, wherein the membrane composition further comprises at least one monomer incorporated into the at least one ligand coated on the AIGS surface.

19. The membrane according to claim 18, wherein the at least one monomer is an acrylate.

20. The membrane according to claim 18, wherein the monomer is at least one of the following: ethyl acrylate, HDDA, tetrahydrofurfuryl acrylate, tris(propylene glycol) diacrylate, 1,4-bis(acryloyloxy)butane, or isobornyl acrylate.

21. The film according to claim 1, which exhibits greater than 95% blue light absorption at 450 nm.

22. A method for preparing a membrane according to any one of claims 1-21, the method comprising: (a) Providing an AIGS nanostructure and at least one ligand coated on the surface of the AIGS nanostructure, wherein the AIGS nanostructure is prepared by a method comprising: ion exchange with gallium by reacting the AIGS core with gallium chloride; (b) Mixing at least one organic resin with the AIGS nanostructure of (a); (c) A first film comprising a mixed AIGS nanostructure, at least one ligand on a coated surface, and at least one organic resin is prepared on a first barrier layer. (d) Curing the membrane; and (e) Encapsulating the first membrane between the first barrier layer and the second barrier layer, and When excited by a blue light source with a wavelength of 450 nm, the encapsulation film exhibits a photon conversion efficiency (PCE) greater than 32% at the peak emission wavelength of 480-545 nm.

23. The method according to claim 22, wherein, The method is performed before the encapsulation film is exposed to the blue LED light source in the air.

24. The method according to claim 22 or 23, wherein the method is carried out under an inert atmosphere.

25. The method according to claim 22 or 23, wherein, The method further includes: At least one oxygen-reactive material is added to the mixture of AIGS nanostructure and ligand in (a), at least one oxygen-reactive material is added to the mixture in (b), and / or a second membrane containing at least one oxygen-reactive material is formed on top of the first membrane prepared in (c), and / or a sacrificial barrier layer temporarily blocking oxygen and / or water is formed on the first membrane prepared in (c), and the PCE of the membrane is measured, and then the sacrificial barrier layer is removed.

26. The method according to claim 22 or 23, wherein the two barrier layers exclude oxygen and / or water.

27. The method of claim 22 or 23 further comprises incorporating at least one monomer into at least one ligand coated on the AIGS surface.

28. A device comprising a membrane according to any one of claims 1-21.

29. A nanostructured molded article, the article comprising: (a) First conductive layer; (b) the second conductive layer; and (c) The membrane between the first conductive layer and the second conductive layer according to any one of claims 1-21.

30. A nanostructure color converter, comprising: Back panel; A display panel, the display panel being disposed on the back panel; and The membrane according to any one of claims 1-21 is disposed on the display panel.

31. The nanostructure color converter of claim 30, wherein the film comprises a patterned AIGS nanostructure.

32. The nanostructure color converter according to claim 30 or 31, wherein the film comprises an AIGS nanostructure and at least one monomer of at least one ligand incorporated into the surface of the AIGS.

33. The nanostructure color converter according to claim 30 or 31, wherein the backplane comprises an LED or an LCD.

34. The nanostructure color converter of claim 33, wherein the LED is selected from OLED or microLED.

Images