Nanostructures with inorganic ligands for electroluminescent devices

Abstract

The present invention relates to highly stable nanostructures having inorganic ligands for use in electroluminescent devices, in particular nanostructure compositions comprising at least one population of nanostructures and at least one fluorine-containing ligand bound to the surface of the nanostructures; wherein the fluorine-containing ligand is selected from fluorozincates, tetrafluoroborates, and hexafluorophosphates. The present invention also relates to highly stable nanostructures comprising at least one population of nanostructures and fluoride anions bound to the surface of the nanostructures. The present invention also relates to a method for preparing such nanostructures.

Description

Technical Field

[0001] The present invention relates to the field of nanotechnology. More specifically, the present invention relates to highly stable nanostructures having inorganic ligands for use in electroluminescent devices, in particular nanostructure compositions comprising at least one population of nanostructures and at least one fluoride containing ligand bound to the surface of the nanostructures; wherein the fluoride containing ligand is selected from fluozincates, tetrafluoroborates and hexafluorophosphates. The present invention also relates to highly stable nanostructures comprising at least one population of nanostructures and fluoride anions bound to the surface of the nanostructures. The present invention also relates to methods for preparing such nanostructures. Background Art

[0002] Semiconductor nanostructures can be incorporated into a variety of electronic and optical devices. The electrical and optical properties of such nanostructures vary, for example, depending on their composition, shape and size. For example, the size tunable properties of semiconductor nanostructures are of great interest for applications such as electroluminescent devices, lasers and biomedical markers. Highly luminescent nanostructures are particularly desirable for electroluminescent device applications.

[0003] Nanostructures in electroluminescent devices are subjected to relatively high voltages during operation (e.g., about 4 V for red nanostructures in a typical lifetime test), which can induce irreversible electrochemical reactions. Organic ligands can be susceptible to electrochemical oxidation. For example, thiolates can be oxidized to thiyl radicals or disulfides. Similarly, carboxylates can be irreversibly oxidized to carbon dioxide. Loss of these ligands results in loss of luminescence, leading to device degradation. Therefore, it is desirable to passivate the nanostructures with ligands having a wide electrochemical window or exhibiting reversible electrochemistry. Summary of the Invention

[0004] The present invention provides a nanostructure composition comprising: (a) at least one population of nanostructures; and (b) at least one fluoride containing ligand bound to the surface of the nanostructures; or (b') fluoride anions bound to the surface of the nanostructures. In some embodiments, the fluoride containing ligand is selected from fluozincates, tetrafluoroborates and hexafluorophosphates.

[0005] In some embodiments, the nanostructures comprise a core and at least one shell.

[0006] In some embodiments, the core comprises Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 、Ge 3 N 4 、Al 2 O 3 、Al 2 OC or a combination thereof.

[0007] In some embodiments, the core comprises InP.

[0008] In some embodiments, the nanostructure includes two shells.

[0009] In some embodiments, at least one shell comprises CdS, CdSe, CdO, CdTe, ZnS, ZnO, ZnSe, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si or an alloy thereof.

[0010] In some embodiments, at least one shell comprises ZnSe.

[0011] In some embodiments, at least one shell comprises ZnS.

[0012] In some embodiments, at least one shell includes a first shell comprising ZnSe and a second shell comprising ZnS.

[0013] In some embodiments, at least one fluorine-containing ligand includes an anion comprising fluozincate and a cation comprising a metal ion. In some embodiments, the cation includes a potassium ion.

[0014] In some embodiments, at least one fluorine-containing ligand includes an anion containing fluozincate and a cation selected from tetraalkylammonium, alkylphosphonium, formamidinium, guanidinium, imidazolium, and pyridinium.

[0015] In some embodiments, the cation is tetraalkylammonium and is selected from dioctadecyldimethylammonium, dihexadecyldimethylammonium, ditetradecyldimethylammonium, didodecyldimethylammonium, didecyldimethylammonium, dioctyldimethylammonium, bis(ethylhexyl)dimethylammonium, octadecyltrimethylammonium, oleyltrimethylammonium, cetyltrimethylammonium, tetradecyltrimethylammonium, dodecyltrimethylammonium, decyltrimethylammonium, octyltrimethylammonium, phenethyltrimethylammonium, benzyltrimethylammonium, phenyltrimethylammonium, benzylhexadecyldimethylammonium, benzyltetradecyldimethylammonium, benzyldodecyldimethylammonium, benzyldecylmethylammonium, benzyloctyldimethylammonium, benzyltributylammonium, benzyltriethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyldimethylammonium, tetraethylammonium, and tetramethylammonium.

[0016] In some embodiments, the cation is alkylphosphonium and is selected from tetraphenylphosphonium, dimethyldiphenylphosphonium, methyltriphenoxophosphonium, hexadecyltributylphosphonium, octyltributylphosphonium, tetradecyltrihexylphosphonium, tetrakis(hydroxymethyl)phosphonium, tetraoctylphosphonium, tetrabutylphosphonium, and tetramethylphosphonium.

[0017] In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand or fluoride anion bound to the nanostructure composition to zinc atoms in the nanostructure composition is between about 0.1 and about 0.5. In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand or fluoride anion bound to the nanostructure composition to zinc atoms in the nanostructure composition is about 0.32.

[0018] In some embodiments, the nanostructure composition further comprises a solvent.

[0019] In some embodiments, the solvent is selected from hexane, heptane, octane, toluene, chloroform, and N-methylformamide.

[0020] In some embodiments, the solvent is a nonpolar solvent.

[0021] In some embodiments, the nanostructure composition further comprises a surfactant.

[0022] In some embodiments, the surfactant is selected from tetramethylammonium acetate, didodecyldimethylammonium bromide, dicetyldimethylammonium bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium bromide, dicetyldimethylammonium bromide, didodecyldimethylammonium bromide, didecyldimethylammonium bromide, dioctyldimethylammonium bromide, bis(2-ethylhexyl)dimethylammonium bromide, octadecyltrimethylammonium bromide, oleyltrimethylammonium bromide, cetyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, decyltrimethylammonium bromide, octyltrimethylammonium bromide, phenethyltrimethylammonium bromide, benzyltrimethylammonium bromide, phenyltrimethylammonium bromide, benzylhexadecyldimethylammonium bromide, benzyltetradecyldimethylammonium bromide, benzyldodecyldimethylammonium bromide, benzyldecyldimethylammonium bromide, benzyloctyldimethylammonium bromide, benzyltributylammonium bromide, benzyltriethylammonium bromide, tetrabutylammonium bromide, tetrapropylammonium bromide, diisopropyldimethylammonium bromide, tetraethylammonium bromide, tetramethylammonium bromide, tetraphenylphosphonium bromide, dimethyldiphenylphosphonium bromide, methyltriphenoxyphosphonium bromide, hexadecyltributylphosphonium bromide, octyltributylphosphonium bromide, tetradecyltrihexylphosphonium bromide, tetrakis(hydroxymethyl)phosphonium bromide, tetraoctylphosphonium bromide, tetrabutylphosphonium bromide, tetramethylphosphonium bromide, dodecylammonium bromide, didodecyldimethylammonium chloride, dicetyldimethylammonium chloride, ditetradecyldimethylammonium chloride, didodecyldimethylammonium chloride, didecyldimethylammonium chloride, dioctyldimethylammonium chloride, bis(2-ethylhexyl)dimethylammonium chloride, octadecyltrimethylammonium chloride, oleyltrimethylammonium chloride, cetyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, decyltrimethylammonium chloride, octyltrimethylammonium chloride, phenethyltrimethylammonium chloride, benzyltrimethylammonium chloride, phenyltrimethylammonium chloride, benzylhexadecyldimethylammonium chloride, benzyltetradecyldimethylammonium chloride, benzyldodecyldimethylammonium chloride, benzyldecyldimethylammonium chloride, benzyloctyldimethylammonium chloride, benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium chloride, tetrapropylammonium chloride, diisopropyldimethylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, tetraphenylphosphonium chloride, dimethyldiphenylphosphonium chloride, methyltriphenoxyphosphonium chloride, hexadecyltributylphosphonium chloride, octyltributylphosphonium chloride, tetradecyltrihexylphosphonium chloride, tetrakis(hydroxymethyl)phosphonium chloride, tetraoctylphosphonium chloride, tetrabutylphosphonium chloride, tetramethylphosphonium chloride, and dodecylammonium chloride.

[0023] In some embodiments, the nanostructured composition exhibits a photoluminescence quantum yield of from about 60% to about 99%. In some embodiments, the nanostructured composition exhibits a photoluminescence quantum yield of from about 70% to about 90%.

[0024] In some embodiments, the nanostructured composition exhibits a photoluminescence peak wavelength between about 600 nm and about 650 nm.

[0025] In some embodiments, the nanostructured composition exhibits a photoluminescence peak wavelength between about 510 nm and about 560 nm.

[0026] In some embodiments, the nanostructured composition exhibits a photoluminescence peak wavelength between about 420 nm and about 470 nm.

[0027] In some embodiments, the fluorinated ligand is a salt of tetrafluorozincate or dichlorodifluorozincate.

[0028] In some embodiments, the fluorinated ligand is tetrabutylammonium tetrafluorozincate or tetrabutylammonium dichlorodifluorozincate.

[0029] In some embodiments, the nanostructure comprises a core comprising InP, at least one shell comprising ZnSe, at least one shell comprising ZnS, and at least one fluorinated ligand comprising a tetrafluorozincate or dichlorodifluorozincate.

[0030] In some embodiments, the nanostructure is a quantum dot.

[0031] The present invention also provides a method for preparing a nanostructured composition, the method comprising: (a) providing at least one population of nanostructures; and (b) mixing at least one fluorinated ligand with the nanostructures; or (b') mixing a tetraalkylammonium fluoride with the nanostructures of (a) to produce a nanostructured composition.

[0032] In some embodiments, the fluorinated ligand is selected from fluorozincates, tetrafluoroborates, and hexafluorophosphates.

[0033] In some embodiments, at least one fluorinated ligand comprises an anion comprising fluorozincate and an inorganic cation comprising a metal ion. In some embodiments, the inorganic cation comprises a potassium ion.

[0034] In some embodiments, the method further comprises (c) mixing at least one organic cation with the nanostructures of (b) or (b') to produce a nanostructured composition.

[0035] In some embodiments, the mixing in (b’) is with a tetraalkylammonium fluoride, wherein the tetraalkylammonium is selected from dioctadecyl dimethylammonium, dihexadecyl dimethylammonium, ditetradecyl dimethylammonium, didodecyl dimethylammonium, didecyl dimethylammonium, dioctyl dimethylammonium, bis(ethylhexyl) dimethylammonium, octadecyl trimethylammonium, oleyl trimethylammonium, hexadecyl trimethylammonium, tetradecyl trimethylammonium, dodecyl trimethylammonium, decyl trimethylammonium, octyl trimethylammonium, phenethyl trimethylammonium, benzyl trimethylammonium, phenyl trimethylammonium, benzyl hexadecyl dimethylammonium, benzyl tetradecyl dimethylammonium, benzyl dodecyl dimethylammonium, benzyl decyl dimethylammonium, benzyl octyl dimethylammonium, benzyl tributylammonium, benzyl triethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyl dimethylammonium, tetraethylammonium, and tetramethylammonium.

[0036] In some embodiments, the organic cation is selected from tetraalkylammonium, alkylphosphonium, formamidinium, guanidinium, imidazolium, and pyridinium.

[0037] In some embodiments, the cation is a tetraalkylammonium and is selected from dioctadecyl dimethylammonium, dihexadecyl dimethylammonium, ditetradecyl dimethylammonium, didodecyl dimethylammonium, didecyl dimethylammonium, dioctyl dimethylammonium, bis(ethylhexyl) dimethylammonium, octadecyl trimethylammonium, oleyl trimethylammonium, hexadecyl trimethylammonium, tetradecyl trimethylammonium, dodecyl trimethylammonium, decyl trimethylammonium, octyl trimethylammonium, phenethyl trimethylammonium, benzyl trimethylammonium, phenyl trimethylammonium, benzyl hexadecyl dimethylammonium, benzyl tetradecyl dimethylammonium, benzyl dodecyl dimethylammonium, benzyl decyl dimethylammonium, benzyl octyl dimethylammonium, benzyl tributylammonium, benzyl triethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyl dimethylammonium, tetraethylammonium, and tetramethylammonium.

[0038] In some embodiments, the cation is an alkylphosphonium and is selected from tetraphenylphosphonium, dimethyldiphenylphosphonium, methyltriphenoxophosphonium, hexadecyl tributylphosphonium, octyl tributylphosphonium, tetradecyl trihexylphosphonium, tetrakis(hydroxymethyl)phosphonium, tetraoctylphosphonium, tetrabutylphosphonium, and tetramethylphosphonium.

[0039] In some embodiments, the nanostructure includes a core and at least one shell.

[0040] In some embodiments, the core comprises Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 、Ge 3 N 4 、Al 2 O 3 、Al 2 OC or a combination thereof.

[0041] In some embodiments, the core comprises InP.

[0042] In some embodiments, the nanostructure comprises two shells.

[0043] In some embodiments, at least one shell comprises CdS, CdSe, CdO, CdTe, ZnS, ZnO, ZnSe, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si or an alloy thereof.

[0044] In some embodiments, at least one shell comprises ZnSe.

[0045] In some embodiments, at least one shell comprises ZnS.

[0046] In some embodiments, at least one shell includes a first shell comprising ZnSe and a second shell comprising ZnS.

[0047] In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand or fluoride anion bound to the nanostructure composition to zinc atoms in the nanostructure composition is between about 0.1 and about 0.5. In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand or fluoride anion bound to the nanostructure composition to zinc atoms in the nanostructure composition is about 0.32.

[0048] In some embodiments, the method further comprises (d) dispersing the nanostructures of (c) in a nonpolar solvent. In some embodiments, the nonpolar solvent is selected from hexane, heptane, octane, toluene, and chloroform.

[0049] In some embodiments, the mixing in (b) or (b’) is carried out at a temperature between about 10 °C and about 100 °C.

[0050] In some embodiments, the mixing in (c) is carried out at a temperature between about 10 °C and about 100 °C.

[0051] In some embodiments, the fluorinated ligand is a salt of tetrafluorozincate or dichlorodifluorozincate.

[0052] In some embodiments, the fluorinated ligand is tetrabutylammonium tetrafluorozincate or tetrabutylammonium dichlorodifluorozincate.

[0053] The present invention also provides a film comprising at least one population of nanostructures, wherein the nanostructures comprise: (a) at least one population of nanostructures comprising a core and at least one shell; and (b) at least one fluorinated ligand bound to the surface of the nanostructures; or (b’) fluoride anions bound to the surface of the nanostructures. In some embodiments, the fluorinated ligand is selected from fluorozincates, tetrafluoroborates, and hexafluorophosphates.

[0054] In some embodiments, the film further comprises at least one organic resin.

[0055] In some embodiments, the film comprises from one to five populations of nanostructures. In some embodiments, the film comprises one population of nanostructures.

[0056] In some embodiments, the at least one population of nanostructures comprises Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 、Ge 3 N 4 、Al 2 O 3 、Al2 OC or a combination thereof.

[0057] In some embodiments, the nanostructure includes a core of InP.

[0058] In some embodiments, the nanostructure includes at least two shells. In some embodiments, the nanostructure includes two shells.

[0059] In some embodiments, at least one shell comprises CdS, CdSe, CdO, CdTe, ZnS, ZnO, ZnSe, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si, or an alloy thereof.

[0060] In some embodiments, at least one shell comprises ZnSe.

[0061] In some embodiments, at least one shell comprises ZnS.

[0062] In some embodiments, at least one shell includes a first shell comprising ZnSe and a second shell comprising ZnS.

[0063] In some embodiments, at least one fluorinated ligand includes an anion comprising fluozincate and a cation comprising a metal ion. In some embodiments, the cation includes a potassium ion.

[0064] In some embodiments, the fluorinated ligand is a salt of tetrafluorozincate or dichlorodifluorozincate.

[0065] In some embodiments, the fluorinated ligand is tetrabutylammonium tetrafluorozincate or tetrabutylammonium dichlorodifluorozincate.

[0066] In some embodiments, at least one fluorinated ligand includes an anion comprising fluozincate and a cation selected from tetraalkylammonium, alkylphosphonium, formamidinium, guanidinium, imidazolium, and pyridinium.

[0067] In some embodiments, the cation is a tetraalkylammonium and is selected from dioctadecyl dimethylammonium, dihexadecyl dimethylammonium, ditetradecyl dimethylammonium, didodecyl dimethylammonium, didecyl dimethylammonium, dioctyl dimethylammonium, bis(ethylhexyl) dimethylammonium, octadecyl trimethylammonium, oleyl trimethylammonium, cetyl trimethylammonium, tetradecyl trimethylammonium, dodecyl trimethylammonium, decyl trimethylammonium, octyl trimethylammonium, phenethyl trimethylammonium, benzyl trimethylammonium, phenyl trimethylammonium, benzyl cetyl dimethylammonium, benzyl tetradecyl dimethylammonium, benzyl dodecyl dimethylammonium, benzyl decyl dimethylammonium, benzyl octyl dimethylammonium, benzyl tributylammonium, benzyl triethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyl dimethylammonium, tetraethylammonium, and tetramethylammonium.

[0068] In some embodiments, the cation is an alkylphosphonium and is selected from tetraphenylphosphonium, dimethyl diphenylphosphonium, methyl triphenoxyoxophosphonium, cetyl tributylphosphonium, octyl tributylphosphonium, tetradecyl trihexylphosphonium, tetrakis(hydroxymethyl)phosphonium, tetraoctylphosphonium, tetrabutylphosphonium, and tetramethylphosphonium.

[0069] In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand or fluoride anion combined with the nanostructure composition to zinc atoms in the nanostructure composition in the nanostructure film is between about 0.1 and about 0.5. In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand or fluoride anion combined with the nanostructure composition to zinc atoms in the nanostructure composition in the nanostructure film is about 0.32.

[0070] In some embodiments, the nanostructure is a quantum dot.

[0071] In some embodiments, the film comprises one to five organic resins. In some embodiments, the film comprises one organic resin.

[0072] In some embodiments, the at least one organic resin is a thermosetting resin or a UV curable resin. In some embodiments, the at least one organic resin is a UV curable resin.

[0073] The present invention also provides a molded article comprising the film according to any one of the above embodiments.

[0074] In some embodiments, the molded article is an electroluminescent device.

[0075] In some embodiments, the electroluminescent device is a light emitting diode or a liquid crystal display.

[0076] In some embodiments, the maximum external quantum efficiency (EQE) of the electroluminescent device is between about 1.5% and about 15%. In some embodiments, the maximum external quantum efficiency (EQE) of the electroluminescent device is about 5%.

[0077] In some embodiments, the electroluminescent device reaches 80% of its initial brightness after about 100 seconds to about 700 seconds. In some embodiments, the electroluminescent device reaches 80% of its initial brightness after 600 seconds.

[0078] In some embodiments, the electroluminescent device reaches 50% of its initial brightness after about 6 hours to about 11 hours. In some embodiments, the electroluminescent device reaches 50% of its initial brightness after about 10 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 is a flow chart showing the ligand exchange process from carboxylate-capped nanostructures to tetrafluorozincate-capped nanostructures with tetraalkylammonium counterions (NMF: N-methylformamide; OA: oleic acid; DDA + : didodecyldimethylammonium; TBA + : tetrabutylammonium).

[0080] Figure 2 is a schematic diagram showing the coordination binding of tetrafluorozincate to the nanostructure surface through monodentate and multidentate coordination modes.

[0081] Figure 3 Shows the following infrared spectra: oleate-capped nanostructures; nanostructures capped with tetrachlorozincate and potassium counterions; and nanostructures capped with tetrachlorozincate and didodecyldimethylammonium counterions.

[0082] Figure 4 Shows the following 1 1H NMR spectra: oleate-capped nanostructures; and nanostructures capped with fluorozincate ligands and didodecyldimethylammonium counterions. The inset shows an enlarged view of the alkyl region.

[0083] Figure 5 Shows the XPS spectra (F 1s region) of the TBA 2 ZnF 4 exchanged blue ZnSe / ZnS nanostructures compared to the unexchanged nanostructures.

[0084] Figure 6 is a flow chart showing the ligand exchange process from carboxylate-capped nanostructures to fluoride-capped nanostructures (TBAF: tetrabutylammonium chloride; OA: oleic acid; DDA + : didodecyldimethylammonium; TBA+ : Tetrabutylammonium; THF: Tetrahydrofuran).

[0085] Figure 7 shows the thermogravimetric analysis of quantum dots with organic (before exchange) ligands and inorganic (ZnF 2 ligand-exchanged and TBAF ligand-exchanged) ligands, which shows that, especially for quantum dots with inorganic ligands, carboxylates (oleates) are significantly removed by decomposition in the temperature range of 320 °C to 480 °C.

[0086] Figure 8 shows ZnF 2 After ligand exchange and TBAF ligand exchange, the height profile and average roughness of the thin film of ligand-exchanged quantum dots. ZnF 2 The quantum dots after ligand exchange show significantly more spikes and increased roughness due to the formation of quantum dot aggregates.

[0087] Figure 9 is a graph showing the efficiency of an electroluminescent device made of quantum dots relative to luminance after ZnF 2 ligand exchange and TBAF ligand exchange. As Figure 9 shown, the quantum dots after TBAF ligand exchange show improved luminance and efficiency. Detailed Description

[0088] Definitions

[0089] 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 belongs. The following definitions are supplementary to those in the art and are specific to this application and not attributable to any related or unrelated cases, such as any co-owned patents or applications. Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing the present invention, the preferred materials and methods are described herein. Thus, the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting.

[0090] As used in this specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a / an" and "the" include plural referents. Thus, for example, reference to "a nanostructure" includes a plurality of such nanostructures, and so on.

[0091] As used herein, the term "about" means a variation of the given value by + / - 10% of that value. For example, "about 100 nm" encompasses a range of sizes from 90 nm to 110 nm, including the endpoints.

[0092] "Nanostructure" refers to a structure having at least one region or feature dimension with a size less than about 500 nm. In some embodiments, the nanostructure has a size 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 feature dimension will be along the smallest axis of the structure. Examples of such structures include nanowires, nanorods, nanotubes, branched nanostructures, nanotetrapods, tripods, bipods, nanocrystals, nanodots, quantum dots, nanoparticles, and the like. A nanostructure can be, for example, substantially crystalline, substantially single-crystalline, 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.

[0093] When used in reference to a nanostructure, the term "heterostructure" refers to a nanostructure characterized by at least two different and / or distinguishable material types. Generally, one region of the nanostructure contains a first material type, while a second region of the nanostructure contains a second material type. In certain embodiments, for example, the nanostructure includes a core of a first material and at least one shell of a second (or third, etc.) material, where the different material types are distributed axially about the long axis of a nanowire, the long axis of the arm of a branched nanowire, or the center axis of a nanocrystal. The shell may, but need not, completely cover the adjacent material 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 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 the arm of a branched nanowire. The different regions within a heterostructure may contain completely different materials, or the different regions may contain a base material (e.g., silicon) having different dopants or different concentrations of the same dopant.

[0094] As used herein, the "diameter" of a nanostructure refers to the diameter of a cross-section perpendicular to a first axis of the nanostructure, where the first axis has the greatest difference in length relative to a second and third axis (the second and third axes being the two axes having the most nearly equal lengths 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 will 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 major and minor axes of the cross-section. For an elongated or high aspect ratio nanostructure, such as a nanowire, the diameter is measured across a cross-section perpendicular to the longest axis of the nanowire. For a spherical nanostructure, the diameter is measured from one side through the center of the sphere to the other side.

[0095] When used in connection with nanostructures, the term "crystalline" or "substantially crystalline" refers to the fact that a nanostructure typically exhibits long range ordering in one or more dimensions of the structure. One of ordinary skill in the art will understand that the term "long range ordering" will depend on the absolute size of the particular nanostructure, as the ordering of a single crystal cannot extend beyond the boundaries of that crystal. In such a case, "long range ordering" will mean substantial order in at least most of the dimensions of the nanostructure. In some cases, a nanostructure may carry an oxide or other coating, or may consist of a core and at least one shell. In such cases, it should be recognized that the oxide, one or more shells, or other coating may or may not exhibit such ordering (e.g., it may be amorphous, polycrystalline, or otherwise). In such cases, the phrases "crystalline", "substantially crystalline", "substantially single crystal", or "single crystal" refer to the central core of the nanostructure (excluding coatings or shells). As used herein, the terms "crystalline" or "substantially crystalline" are also intended to include structures containing various defects, stacking faults, atomic substitutions, etc., provided that the structure exhibits substantial long range ordering (e.g., order over at least about 80% of the length of at least one axis of the nanostructure or its core). Further, it should be understood that the interface 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, may contain amorphous regions and may even be amorphous. This does not prevent the nanostructure from being crystalline or substantially crystalline as defined herein.

[0096] When used in connection with nanostructures, the term "single crystal" means that the nanostructure is substantially crystalline and substantially comprises a single crystal. When used in connection with a nanostructure heterostructure comprising a core and one or more shells, "single crystal" means that the core is substantially crystalline and substantially comprises a single crystal.

[0097] A "nanocrystal" is a nanostructure that is substantially a single crystal. Thus, a nanocrystal has at least one region or characteristic dimension less than about 500 nm. In some embodiments, the nanocrystal has a size 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 include substantially single crystal nanostructures containing various defects, stacking faults, atomic substitutions, etc., as well as substantially single crystal nanostructures without such defects, 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 a single crystal, but the one or more shells need not be. 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.

[0098] The term "quantum dot" (or "dot") refers to a nanocrystal that exhibits quantum confinement or exciton confinement. Quantum dots can be substantially uniform in terms of material properties or, in certain embodiments, can be non-uniform, e.g., comprising a core and at least one shell. The optical properties of quantum dots can be affected 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 adjust the nanocrystal size, e.g., in the range of about 1 nm to about 15 nm, enables light emission coverage across the entire spectrum to provide great versatility in color rendering.

[0099] As used herein, the term "monolayer" is a unit of measure of the shell thickness derived from the bulk crystal structure of the shell material, as the closest distance between relevant lattice planes. By way of example, for a cubic lattice structure, the thickness of one monolayer is determined as the distance between adjacent lattice planes in the

[111] direction. By way of example, one monolayer of cubic ZnSe corresponds to 0.328 nm, while one monolayer of cubic ZnS corresponds to a thickness of 0.31 nm. The thickness of a monolayer of an alloy material can be determined from the alloy composition by Vegard's law.

[0100] As used herein, the term "shell" refers to a material deposited on a core or on a previously deposited shell of the same or different composition, which results from a single deposition act of the shell material. The exact shell thickness depends on the material as well as precursor input and conversion and can be reported in nanometers or monolayers. As used herein, "target shell thickness" refers to a predetermined shell thickness used to calculate the required precursor amount. As used herein, "actual shell thickness" refers to the actual deposited amount of the shell material after synthesis and can be measured by methods known in the art. By way of example, the actual shell thickness can be measured by comparing the particle diameters determined from transmission electron microscopy (TEM) images of the nanocrystals before and after shell synthesis.

[0101] As used herein, the term "layer" refers to a material deposited on a core or on a previously deposited layer, which results from a single deposition act of the core or shell material. The exact layer thickness depends on the material. For example, the thickness of a ZnSe layer can be about 0.328 nm, while the thickness of a ZnS layer can be about 0.31 nm.

[0102] A "ligand" is a molecule capable of interacting (either weakly or strongly) with one or more faces of a nanostructure, e.g., by covalent, ionic, van der Waals, or other molecular interactions with the surface of the nanostructure.

[0103] "Photoluminescence quantum yield" is the ratio of the photons emitted to the photons absorbed, e.g., emitted or absorbed by a nanostructure or a population of nanostructures. As is known in the art, the quantum yield is typically determined by a comparative method using a well-characterized standard sample with a known quantum yield value.

[0104] The "peak emission wavelength" (PWL) is the wavelength at which the radiative emission spectrum of a light source reaches its maximum.

[0105] As used herein, the term "full width at half maximum" (FWHM) is a measure of the size distribution of quantum dots. The emission spectrum of quantum dots generally has the shape of a Gaussian curve. The width of the Gaussian curve is defined as the FWHM, giving an idea of the particle size distribution. A smaller FWHM corresponds to a narrower size distribution of quantum dot nanocrystals. The FWHM also depends on the emission wavelength maximum.

[0106] As used herein, the term "external quantum efficiency" (EQE) is the ratio of the number of photons emitted from a light-emitting diode to the number of electrons passing through the device. The EQE measures how efficiently a light-emitting diode converts electrons into photons and allows them to escape. The EQE can be measured using the following formula:

[0107] EQE = [Injection efficiency] × [Solid-state quantum yield] × [Extraction efficiency]

[0108] Where:

[0109] Injection efficiency = the proportion of electrons passing through the device that are injected into the active region;

[0110] Solid-state quantum yield = the proportion of all electron-hole recombinations in the active region that are radiative and thus produce photons; and

[0111] Extraction efficiency = the proportion of photons generated in the active region that escape from the device.

[0112] As used herein, the term "stable" means that a mixture or composition resists changes or decomposition due to internal reactions or due to the action of air, heat, light, pressure, other natural conditions, voltage, current, brightness, or other operating conditions. The colloidal stability of a nanostructured composition can be determined by measuring the peak absorption wavelength after mixing at least one population of nanostructures with at least one solvent. The peak absorption wavelength can be measured by irradiating the nanostructured composition with UV or blue (450 nm) light and measuring its output with a spectrophotometer. The absorption spectrum is compared with the absorption from the original nanostructured composition. If the shift in the peak absorption wavelength does not exceed 5 nm, the colloidal nanostructured composition is stable.

[0113] Unless otherwise expressly stated, the ranges recited herein are inclusive of the endpoints.

[0114] Various additional terms are defined or otherwise characterized herein.

[0115] As discussed above, there is a need to prepare nanostructured compositions having a wide electrochemical window or exhibiting reversible electrochemistry. Disclosed herein is a method for passivating nanostructures with inorganic ligands. The method includes replacing native organic ligands on quantum dots with inorganic halometallate ligands via a post-synthesis ligand exchange process. This results in a longer operating lifetime of an electroluminescent device due to the improved electrochemical stability of the nanostructure-ligand complex.

[0116] Nanostructured composition

[0117] In some embodiments, the present disclosure provides a nanostructured composition comprising:

[0118] (a) at least one population of nanostructures; and

[0119] (b) at least one fluorine-containing ligand bound to the surface of the nanostructures;

[0120] wherein the fluorine-containing ligand is selected from fluorozincate, tetrafluoroborate, and hexafluorophosphate.

[0121] In some embodiments, the present disclosure provides a nanostructured composition comprising:

[0122] (a) at least one population of nanostructures; and

[0123] (b) fluoride anions bound to the surface of the nanostructures.

[0124] In some embodiments, the nanostructures include a core and at least one shell.

[0125] In some embodiments, the nanostructures are quantum dots.

[0126] Nanostructured film

[0127] In some embodiments, the present disclosure provides a nanostructured film comprising at least one population of nanostructures, wherein the nanostructures include:

[0128] (a) at least one population of nanostructures, the nanostructures including a core and at least one shell; and

[0129] (b) at least one fluorine-containing ligand bound to the surface of the nanostructures;

[0130] wherein the fluorine-containing ligand is selected from fluorozincate, tetrafluoroborate, and hexafluorophosphate.

[0131] In some embodiments, the present disclosure provides a nanostructured film comprising at least one population of nanostructures, wherein the nanostructures include:

[0132] (a) At least one population of nanostructures, said nanostructures comprising a core and at least one shell; and

[0133] (b) Fluoride anions bound to the surface of said nanostructures.

[0134] In some embodiments, the nanostructure film further comprises at least one organic resin.

[0135] In some embodiments, the nanostructures are quantum dots.

[0136] Nanostructure molded article

[0137] In some embodiments, the present invention provides a molded article comprising said nanostructure film.

[0138] In some embodiments, the molded article comprises:

[0139] (a) A first barrier layer;

[0140] (b) A second barrier layer; and

[0141] (c) An emission layer between said first barrier layer and said second barrier layer, wherein said emission layer comprises a population of nanostructures, said population of nanostructures comprising at least one population of nanostructures; and at least one fluorine-containing ligand bound to the surface of said nanostructures; wherein said fluorine-containing ligand is selected from fluozincate, tetrafluoroborate and hexafluorophosphate.

[0142] In some embodiments, the molded article comprises:

[0143] (a) A first barrier layer;

[0144] (b) A second barrier layer; and

[0145] (c) An emission layer between said first barrier layer and said second barrier layer, wherein said emission layer comprises a population of nanostructures, said population of nanostructures comprising at least one population of nanostructures and fluoride anions bound to the surface of said nanostructures.

[0146] In some embodiments, the nanostructures are quantum dots.

[0147] In some embodiments, the molded article is an electroluminescent device. In some embodiments, the molded article is a light emitting diode. In some embodiments, the molded article is a liquid crystal display.

[0148] Core nanostructure

[0149] Methods for the colloidal synthesis of various nanostructures are known in the art. Such methods include techniques for controlling the growth of nanostructures, e.g., controlling the size and / or shape distribution of the resulting nanostructures.

[0150] In a typical colloidal synthesis, semiconductor nanostructures are generated by rapidly injecting precursors that undergo pyrolysis into a hot solution (e.g., a hot solvent and / or surfactant). The precursors can be injected simultaneously or sequentially. The precursors react rapidly to form nuclei. Nanostructure growth occurs by adding monomers to the nuclei, typically at a growth temperature that is lower than the injection / nucleation temperature.

[0151] Ligands interact with the surface of the nanostructures. At the growth temperature, the ligands rapidly adsorb and desorb from the nanostructure surface, allowing atoms to be added to and / or removed from the nanostructure while inhibiting aggregation of the growing nanostructures. Generally, ligands that are weakly coordinated to the nanostructure surface allow for rapid nanostructure growth, while ligands that bind more strongly to the nanostructure surface result in slower nanostructure growth. Ligands can also interact with one (or more) precursors to slow down nanostructure growth.

[0152] Nanostructure growth in the presence of a single ligand typically results in spherical nanostructures. However, if, for example, two (or more) ligands adsorb differently to different crystal faces of the growing nanostructure, then the use of a mixture of two or more ligands allows for control of growth such that non-spherical nanostructures can be produced.

[0153] Thus, many parameters are known to affect nanostructure growth and can be manipulated individually or in combination to control the size and / or shape distribution of the resulting nanostructures. These include, e.g., temperature (nucleation and / or growth), precursor composition, time-dependent precursor concentration, ratios of precursors to one another, surfactant composition, surfactant amount, and ratios of surfactants to one another and / or to precursors.

[0154] In some embodiments, the nanostructure is cadmium-free. As used herein, the term "cadmium-free" means that the nanostructure contains less than 100 ppm of cadmium by weight. The Restriction of Hazardous Substances (RoHS) compliance definition requires that the cadmium content in the original homogeneous precursor material not exceed 0.01% (100 ppm) by weight. The cadmium level in the Cd-free nanostructures of the present invention is limited by the trace metal concentration in the precursor material. The concentration of trace metals (including cadmium) in the precursor material for Cd-free nanostructures 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 "cadmium-free" nanostructure contains less than about 50 ppm, less than about 20 ppm, less than about 10 ppm, or less than about 1 ppm of cadmium.

[0155] In one embodiment, the core comprises Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 、Ge 3 N 4 、Al 2 O 3 、Al 2 OC or a combination thereof.

[0156] In some embodiments, the core is a Group III-V nanostructure. In some embodiments, the core is a Group III-V nanocrystal selected from BN, BP, BAs, BSb, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, and InSb. In some embodiments, the core is an InP nanocrystal.

[0157] The synthesis of group III-V nanostructures has been described in U.S. Pat. Nos. 5,505,928, 6,306,736, 6,576,291, 6,788,453, 6,821,337, 7,138,098, 7,557,028, 8,062,967, 7,645,397, and 8,282,412 and in U.S. Patent Application No. 2015 / 236,195. The synthesis of group III-V nanostructures has also been described in Wells, RL, et al., "The use of tris(trimethylsilyl)arsine to prepare gallium arsenide and indiumarsenide," Chem. Mater. 1: 4-6 (1989) and in Guzelian, AA, et al., "Colloidal chemical synthesis and characterization of InAs nanocrystal quantum dots," Appl. Phys. Lett. 69: 1432-1434 (1996).

[0158] The synthesis of InP-based nanostructures has been described in, for example, Xie, R., et al., "Colloidal InP nanocrystals as efficient emitters covering blue to near-infrared," J. Am. Chem. Soc. 129:15432-15433 (2007); Micic, O. I., et al., "Core-shell quantumdots of lattice-matched ZnCdSe 2shells on InP cores:Experiment and theory,"J.Phys.Chem.B 104:12149-12156(2000);Liu,Z.,et al.,"Coreduction colloidalsynthesis of III-V nanocrystals:The case of InP,"Angew.Chem.Int.Ed.Engl.47:3540-3542(2008);Li,L.et al.,"Economic synthesis of high quality InPnanocrystals using calcium phosphide as the phosphorus precursor,"Chem.Mater.20:2621-2623(2008);D.Battaglia and X.Peng,"Formation of highquality InP and InAs nanocrystals in a noncoordinating solvent,"Nano Letters2:1027-1030(2002);Kim,S.,et al.,"Highly luminescent InP / GaP / ZnS nanocrystalsand their application to white light-emitting diodes,"J.Am.Chem.Soc.134:3804-3809(2012);Nann,T.,et al.,"Water splitting by visible light:Ananophotocathode for hydrogen production,"Angew.Chem.Int.Ed.49:1574-1577(2010);Borchert,H.,et al.,"Investigation of ZnS passivated InP nanocrystalsby XPS,"Nano Letters 2:151-154(2002);L.Li and P.Reiss,"One-pot synthesis ofhighly luminescent InP / ZnS nanocrystals without precursor injection,"J.Am.Chem.Soc.130:11588-11589(2008); Hussain, S., et al. "One-pot fabrication of high-quality InP / ZnS(core / shell) quantum dots and their application to cellular imaging," Chemphyschem. 10:1466-1470(2009); Xu, S., et al., "Rapid synthesis of high-quality InP nanocrystals," J. Am. Chem. Soc. 128:1054-1055(2006); Micic, O. I., et al., "Size-dependent spectroscopy of InP quantum dots," J. Phys. Chem. B 101:4904-4912(1997); Haubold, S., et al., "Strongly luminescent InP / ZnS core-shell nanoparticles," Chemphyschem. 5:331-334(2001); Cros Gagneux, A., et al., "Surface chemistry of InP quantum dots: A comprehensive study," J. Am. Chem. Soc. 132:18147-18157(2010); Micic, O. I., et al., "Synthesis and characterization of InP, GaP, and GaInP. 2"Quantum dots," J. Phys. Chem. 99:7754 - 7759 (1995); Guzelian, A. A., et al., "Synthesis of size - selected, surface - passivated InP nanocrystals," J. Phys. Chem. 100:7212 - 7219 (1996); Lucey, D. W., et al., "Monodispersed InP quantum dots prepared by colloidal chemistry in a non - coordinating solvent," Chem. Mater. 17:3754 - 3762 (2005); Lim, J., et al., "InP@ZnSeS, core@composition gradient shell quantum dots with enhanced stability," Chem. Mater. 23:4459 - 4463 (2011); and Zan, F., et al., "Experimental studies on blinking behavior of single InP / ZnS quantum dots: Effects of synthetic conditions and UV irradiation," J. Phys. Chem. C 116:394 - 3950 (2012). However, such efforts have met with only limited success in producing InP nanostructures with high quantum yields.

[0159] In some embodiments, the core is doped. In some embodiments, the dopant of the nanocrystal core includes a metal, which includes 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 includes a non - metal. In some embodiments, the dopant is ZnS, ZnSe, ZnTe, CdSe, CdS, CdTe, HgS, HgSe, HgTe, CuInS2, CuInSe2, AlN, AlP, AlAs, GaN, GaP, or GaAs.

[0160] In some embodiments, the core is a Group II-VI nanocrystal selected from ZnO, ZnSe, ZnS, ZnTe, CdO, CdSe, CdS, CdTe, HgO, HgSe, HgS, and HgTe. In some embodiments, the core is a nanocrystal selected from ZnSe, ZnS, CdSe, and CdS. The synthesis of Group II-VI nanostructures is described in U.S. Patent Nos. 6225198, 6322901, 6207229, 6607829, 7060243, 7374824, 6861155, 7125605, 7566476, 8158193, and 8101234, as well as U.S. Patent Application Nos. 2011 / 0262752 and 2011 / 0263062.

[0161] Although Group II-VI nanostructures such as CdSe and CdS quantum dots can exhibit desirable luminescent behavior, issues such as the toxicity of cadmium limit the applications in which such nanostructures can be employed. Thus, less toxic alternatives with favorable luminescent properties are highly desirable. Generally, Group III-V nanostructures, and in particular InP-based nanostructures, provide the most well-known alternatives to cadmium-based materials due to their compatible emission ranges.

[0162] In some embodiments, the core is purified prior to the deposition of the shell. In some embodiments, the core is filtered to remove precipitates from the core solution.

[0163] In some embodiments, an acid etching step is performed on the core prior to the deposition of the shell.

[0164] In some embodiments, quantum confinement is used to determine the diameter of the core. Quantum confinement in zero-dimensional nanocrystals (such as quantum dots) results from the spatial confinement of electrons within the grain boundaries. Quantum confinement can be observed once the diameter of the material is on the order of the de Broglie wavelength of the wave function. The electrical and optical properties of the nanoparticles deviate substantially from those of the bulk material. When the confinement size is large compared to the wavelength of the particle, the particle behaves as if it were free. During this state, the bandgap remains at its initial energy due to the continuous energy states. However, as the confinement size decreases and reaches a certain limit, typically at the nanoscale, the energy spectrum becomes discrete. As a result, the bandgap becomes size-dependent. The size can be determined as known in the art, for example, using transmission electron microscopy and / or physical modeling. In some embodiments, the diameter of the core nanostructure is between about 1 nm and about 9 nm, between about 1 nm and about 8 nm, between about 1 nm and about 7 nm, between about 1 nm and about 6 nm, between about 1 nm and about 5 nm, between about 1 nm and about 4 nm, between about 1 nm and about 3 nm, between about 1 nm and about 2 nm, between about 2 nm and about 9 nm, between about 2 nm and about 8 nm, between about 2 nm and about 7 nm, between about 2 nm and about 6 nm, between about 2 nm and about 5 nm, between about 2 nm and about 4 nm, between about 2 nm and about 3 nm, between about 3 nm and about 9 nm, between about 3 nm and about 8 nm, between about 3 nm and about 7 nm, between about 3 nm and about 6 nm, between about 3 nm and about 5 nm, between about 3 nm and about 4 nm, between about 4 nm and about 9 nm, between about 4 nm and about 8 nm, between about 4 nm and about 7 nm, between about 4 nm and about 6 nm, between about 4 nm and about 5 nm, between about 5 nm and about 9 nm, between about 5 nm and about 8 nm, between about 5 nm and about 7 nm, between about 5 nm and about 6 nm, between about 6 nm and about 9 nm, between about 6 nm and about 8 nm, between about 6 nm and about 7 nm, between about 7 nm and about 9 nm, between about 7 nm and about 8 nm, or between about 8 nm and about 9 nm. In some embodiments, the diameter of the core nanostructure is about 7 nm.

[0165] Shell

[0166] In some embodiments, the nanostructures of the present disclosure include a core and at least one shell. In some embodiments, the nanostructure includes a core and at least two shells. In some embodiments, the nanostructure includes a core and two shells.

[0167] The shell can, for example, improve the quantum yield and / or stability of the nanostructure. In some embodiments, the core and the shell comprise different materials. In some embodiments, the nanostructure includes shells having different shell materials.

[0168] In some embodiments, a shell comprising a mixture of Group II and Group VI elements is deposited on a core or core / shell structure. In some embodiments, the shell is deposited by a mixture of at least two of a zinc source, a selenium source, a sulfur source, a tellurium source, and a cadmium source. In some embodiments, the shell is deposited by a mixture of two of a zinc source, a selenium source, a sulfur source, a tellurium source, and a cadmium source. In some embodiments, the shell is deposited by a mixture of three of a zinc source, a selenium source, a sulfur source, a tellurium source, and a cadmium source. In some embodiments, the shell comprises zinc and sulfur; zinc and selenium; zinc, sulfur, and selenium; zinc and tellurium; zinc, tellurium, and sulfur; zinc, tellurium, and selenium; zinc, cadmium, and sulfur; zinc, cadmium, and selenium; cadmium and sulfur; cadmium and sulfur; cadmium and selenium; cadmium and selenium; cadmium, selenium, and sulfur; cadmium, zinc, and sulfur; cadmium, zinc, and selenium; or cadmium, zinc, sulfur, and selenium.

[0169] In some embodiments, at least one shell comprises CdS, CdSe, CdO, CdTe, ZnS, ZnO, ZnSe, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si, or an alloy thereof. In some embodiments, at least one shell comprises ZnSe. In some embodiments, at least one shell comprises ZnS. In some embodiments, at least one shell includes a first shell comprising ZnSe and a second shell comprising ZnS.

[0170] In some embodiments, the shell comprises more than one monolayer of shell material. The number of monolayers is an average taken over all of the nanostructures; thus, the number of monolayers in the shell can be a fraction. In some embodiments, the number of monolayers in the shell is between 0.25 and 10, between 0.25 and 8, between 0.25 and 7, between 0.25 and 6, between 0.25 and 5, between 0.25 and 4, between 0.25 and 3, between 0.25 and 2, between 2 and 10, between 2 and 8, between 2 and 7, between 2 and 6, between 2 and 5, between 2 and 4, between 2 and 3, between 3 and 10, between 3 and 8, between 3 and 7, between 3 and 6, between 3 and 5, between 3 and 4, between 4 and 10, between 4 and 8, between 4 and 7, between 4 and 6, between 4 and 5, between 5 and 10, between 5 and 8, between 5 and 7, between 5 and 6, between 6 and 10, between 6 and 8, between 6 and 7, between 7 and 10, between 7 and 8, or between 8 and 10. In some embodiments, the shell comprises 3 to 5 monolayers.

[0171] The thickness of the shell can be controlled by varying the amount of the precursors provided. For a given shell thickness, at least one of the precursors is optionally provided in an amount such that, when the growth reaction is substantially complete, a shell of a predetermined thickness is obtained. If more than one different precursor is provided, the amount of each precursor can be restricted, or one of the precursors can be provided in a restricted amount while the others are provided in excess.

[0172] The thickness of each shell can be determined using techniques known to those skilled in the art. In some embodiments, the thickness of each shell is determined by comparing the average diameter of the nanostructure before and after adding each shell. In some embodiments, the average diameter of the nanostructure before and after adding each shell is determined by TEM. In some embodiments, the thickness of each shell is between about 0.05 nm and about 3.5 nm, between about 0.05 nm and about 2 nm, between about 0.05 nm and about 0.9 nm, between about 0.05 nm and about 0.7 nm, between about 0.05 nm and about 0.5 nm, between about 0.05 nm and about 0.3 nm, between about 0.05 nm and about 0.1 nm, between about 0.1 nm and about 3.5 nm, between about 0.1 nm and about 2 nm, between about 0.1 nm and about 0.9 nm, between about 0.1 nm and about 0.7 nm, between about 0.1 nm and about 0.5 nm, between about 0.1 nm and about 0.3 nm, between about 0.3 nm and about 3.5 nm, between about 0.3 nm and about 2 nm, between about 0.3 nm and about 0.9 nm, between about 0.3 nm and about 0.7 nm, between about 0.3 nm and about 0.5 nm, between about 0.5 nm and about 3.5 nm, between about 0.5 nm and about 2 nm, between about 0.5 nm and about 0.9 nm, between about 0.5 nm and about 0.7 nm, between about 0.7 nm and about 3.5 nm, between about 0.7 nm and about 2 nm, between about 0.7 nm and about 0.9 nm, between about 0.9 nm and about 3.5 nm, between about 0.9 nm and about 2 nm, or between about 2 nm and about 3.5 nm.

[0173] In some embodiments, each shell is synthesized in the presence of at least one nanostructure ligand. The ligand can, for example, enhance the miscibility of the nanostructure in a solvent or polymer (allowing the nanostructure to be distributed throughout the composition such that the nanostructures do not aggregate together), increase the quantum yield of the nanostructure, and / or maintain the luminescence of the nanostructure (e.g., when the nanostructure is introduced into a matrix). In some embodiments, the ligand used for core synthesis and the ligand used for shell synthesis are the same. In some embodiments, the ligand used for core synthesis and the ligand used for shell synthesis are different. After synthesis, any ligand on the surface of the nanostructure can be exchanged for a different ligand with other desired properties. 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.

[0174] Ligands suitable for shell synthesis are known to those skilled in the art. In some embodiments, the ligand is a fatty acid selected from lauric acid, caproic acid, myristic acid, palmitic acid, stearic acid, and oleic acid. In some embodiments, the ligand is an organophosphine or organophosphine oxide selected from trioctylphosphine oxide, trioctylphosphine, diphenylphosphine, triphenylphosphine oxide, and tributylphosphine oxide. In some embodiments, the ligand is an amine of a group selected from dodecylamine, oleylamine, hexadecylamine, dioctylamine, and octadecylamine. In some embodiments, the ligand is tributylphosphine, oleic acid, or zinc oleate.

[0175] In some embodiments, each shell is produced in the presence of a ligand mixture. In some embodiments, each shell is produced in the presence of a mixture containing 2, 3, 4, 5, or 6 different ligands. In some embodiments, each shell is produced in the presence of a mixture containing 3 different ligands. In some embodiments, the ligand mixture contains tributylphosphine, oleic acid, and zinc oleate.

[0176] In some embodiments, each shell is produced in the presence of a solvent. In some embodiments, the solvent is selected from 1-octadecene, 1-hexadecene, 1-eicosene, eicosane, octadecane, hexadecane, tetradecane, squalene, squalane, trioctylphosphine oxide, and dioctyl ether. In some embodiments, the solvent is 1-octadecene.

[0177] In some embodiments, the core or core / shell is contacted with the shell precursor at an addition temperature between about 20°C and about 310°C, between about 20°C and about 280°C, between about 20°C and about 250°C, between about 20°C and about 200°C, between about 20°C and about 150°C, between about 20°C and about 100°C, between about 20°C and about 50°C, between about 50°C and about 310°C, between about 50°C and about 280°C, between about 50°C and about 250°C, between about 50°C and about 200°C, between about 50°C and about 150°C, between about 50°C and about 100°C, between about 100°C and about 310°C, between about 100°C and about 280°C, between about 100°C and about 250°C, between about 100°C and about 200°C, between about 100°C and about 150°C, between about 150°C and about 310°C, between about 150°C and about 280°C, between about 150°C and about 250°C, between about 150°C and about 200°C, between about 200°C and about 310°C, between about 200°C and about 280°C, between about 200°C and about 250°C, between about 250°C and about 310°C, between about 250°C and about 280°C, between about 280°C and about 310°C. In some embodiments, the core or core / shell is contacted with the shell precursor at an addition temperature between about 20°C and about 100°C.

[0178] In some embodiments, after the core or core / shell is contacted with the shell precursor, the temperature of the reaction mixture is raised to a high temperature between about 200°C and about 310°C, between about 200°C and about 280°C, between about 200°C and about 250°C, between about 200°C and about 220°C, between about 220°C and about 310°C, between about 220°C and about 280°C, between about 220°C and about 250°C, between about 250°C and about 310°C, between about 250°C and about 280°C, between about 280°C and about 310°C. In some embodiments, after the core or core / shell is contacted with the shell precursor, the temperature of the reaction mixture is increased to between about 250°C and about 310°C.

[0179] In some embodiments, after the core or core / shell contacts the shell precursor, the time for the temperature to reach the high temperature is between about 2 and about 240 minutes, between about 2 and about 200 minutes, between about 2 and about 100 minutes, between about 2 and about 60 minutes, between about 2 and about 40 minutes, between about 5 and 240 minutes, between about 5 and about 200 minutes, between about 5 and about 100 minutes, between about 5 and about 60 minutes, between about 5 and about 40 minutes, between about 10 and about 240 minutes, between about 10 and about 200 minutes, between about 10 and about 100 minutes, between about 10 and about 60 minutes, between about 10 and about 40 minutes, between about 40 and about 240 minutes, between about 40 and about 200 minutes, between about 40 and about 100 minutes, between about 40 and about 60 minutes, between about 60 and about 240 minutes, between about 60 and about 200 minutes, between about 60 and about 100 minutes, between about 100 and about 240 minutes, between about 100 and 200 minutes, or between about 200 and 240 minutes.

[0180] In some embodiments, after the core or core / shell contacts the shell precursor, the temperature of the reaction mixture is maintained at the high temperature for about 2 to about 240 minutes, about 2 to about 200 minutes, about 2 to about 100 minutes, about 2 to about 60 minutes, about 2 to about 60 minutes 40 minutes, about 5 to about 240 minutes, about 5 to about 200 minutes, about 5 to about 100 minutes, about 5 to about 60 minutes, about 5 to about 40 minutes, about 10 to about 240 minutes, about 10 to about 200 minutes, about 10 to about 100 minutes, about 10 to 60 minutes, about 10 to 40 minutes, about 40 to 240 minutes, about 40 to 200 minutes, about 40 to 100 minutes, about 40 to 60 minutes, about 60 to 240 minutes, about 60 to 200 minutes, about 60 to about 100 minutes, about 100 to about 240 minutes, about 100 to about 200 minutes, or about 200 to about 240 minutes. In some embodiments, after the core or core / shell contacts the shell precursor, the temperature of the reaction mixture is maintained at the high temperature for about 30 to about 120 minutes.

[0181] In some embodiments, an additional shell is produced by further adding a shell material precursor that is added to the reaction mixture and then maintaining at the high temperature. Typically, the additional shell precursor is provided when the reaction of the prior shell is substantially complete (e.g., when at least one of the precursors is depleted or removed from the reaction or when no further growth is detectable). The further addition of the precursor produces an additional shell.

[0182] In some embodiments, the nanostructure is cooled before adding an additional shell material precursor to provide a further shell. In some embodiments, the nanostructure is maintained at the high temperature before adding the shell material precursor to provide a further shell.

[0183] After adding a sufficient number of layers of the shell to the nanostructure to achieve the desired thickness and diameter, the nanostructure can be cooled. In some embodiments, the core / shell nanostructure is cooled to room temperature. In some embodiments, an organic solvent is added to dilute the reaction mixture containing the core / shell nanostructure.

[0184] In some embodiments, the organic solvent used to dilute the reaction mixture is ethanol, hexane, pentane, toluene, benzene, diethyl ether, acetone, ethyl acetate, dichloromethane (methylene chloride), chloroform, dimethylformamide, or N-methylpyrrolidone. In some embodiments, the organic solvent is toluene.

[0185] In some embodiments, the core / shell nanostructure is separated. In some embodiments, the core / shell nanostructure is separated by precipitation using an organic solvent. In some embodiments, the core / shell nanostructure is separated by flocculation with ethanol.

[0186] The number of monolayers will determine the size of the core / shell nanostructure. The size of the core / shell nanostructure can be determined using techniques known to those skilled in the art. In some embodiments, the size of the core / shell nanostructure is determined using TEM. In some embodiments, the average diameter of the core / shell nanostructure is between about 1 nm and about 15 nm, between about 1 nm and about 10 nm, between about 1 nm and about 9 nm, between about 1 nm and about 8 nm, between about 1 nm and about 7 nm, between about 1 nm and about 6 nm, between about 1 nm and about 5 nm, between about 5 nm and about 15 nm, between about 5 nm and about 10 nm, between about 5 nm and about 9 nm, between about 5 nm and about 8 nm, between about 5 nm and about 7 nm, between about 5 nm and about 6 nm, between about 6 nm and about 15 nm, between about 6 nm and about 10 nm, between about 6 nm and about 9 nm, between about 6 nm and about 8 nm, between about 6 nm and about 7 nm, between about 7 nm and about 15 nm, between about 7 nm and about 10 nm, between about 7 nm and about 9 nm, between about 7 nm and about 8 nm, between about 8 nm and about 15 nm, between about 8 nm and about 10 nm, between about 8 nm and about 9 nm, between about 9 nm and about 15 nm, between about 9 nm and about 10 nm, or between about 10 nm and about 15 nm. In some embodiments, the average diameter of the core / shell nanostructure is between about 6 nm and about 7 nm.

[0187] Nanostructure composition

[0188] In some embodiments, the present disclosure provides a nanostructure composition comprising:

[0189] (a) at least one population of nanostructures; and

[0190] (b) at least one fluorine-containing ligand bound to the surface of the nanostructure; or

[0191] (b’) fluoride anions bound to the surface of the nanostructure;

[0192] wherein the fluorine-containing ligand is selected from fluozincate, tetrafluoroborate, and hexafluorophosphate.

[0193] In some embodiments, the nanostructure includes a core and at least one shell.

[0194] In some embodiments, the core contains Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 、Ge 3 N 4 、Al 2 O 3 、Al 2 OC or a combination thereof. In some embodiments, the core contains InP.

[0195] In some embodiments, the nanostructure includes two shells.

[0196] In some embodiments, the at least one shell contains CdS, CdSe, CdO, CdTe, ZnS, ZnO, ZnSe, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si, or an alloy thereof. In some embodiments, the at least one shell contains ZnSe. In some embodiments, at least one shell contains ZnS. In some embodiments, the at least one shell includes a first shell containing ZnSe and a second shell containing ZnS.

[0197] In some embodiments, the core / shell nanostructure is prepared by the method of U.S. Application Publication No. 2017 / 0306227, which is incorporated herein by reference in its entirety.

[0198] In some embodiments, the core / shell nanostructure is a core / ZnSe / ZnS nanostructure. In some embodiments, the core / shell nanostructure is an InP / ZnSe / ZnS nanostructure. In some embodiments, the core / shell nanostructure comprises a core containing InP, at least one shell containing ZnSe, at least one shell containing ZnS, and at least one fluorine-containing ligand that is a salt comprising tetrafluorozincate or dichlorodifluorozincate.

[0199] In some embodiments, the nanostructure is a quantum dot.

[0200] Fluorine-containing ligand

[0201] In some embodiments, the nanostructure composition comprises at least one fluorine-containing ligand bound to the surface of the nanostructure. In some embodiments, the nanostructure composition comprises one fluorine-containing ligand bound to the surface of the nanostructure. In some embodiments, the fluorine-containing ligand is an inorganic ligand.

[0202] In some embodiments, the at least one fluorine-containing ligand comprises an anion comprising fluorozincate and an inorganic cation. In some embodiments, the inorganic cation comprises a metal ion. In some embodiments, the cation comprises a potassium ion.

[0203] In some embodiments, the at least one fluorine-containing ligand comprises an anion including fluozincate and an organic cation. In some embodiments, the organic cation is selected from tetraalkylammonium, alkylphosphonium, imidazolium, formamidinium, guanidinium, and pyridinium. In some embodiments, the organic cation is tetraalkylammonium and is selected from dioctadecyl dimethylammonium, dihexadecyl dimethylammonium, ditetradecyl dimethylammonium, didodecyl dimethylammonium, didecyl dimethylammonium, dioctyl dimethylammonium, bis(ethylhexyl)dimethylammonium, octadecyl trimethylammonium, oleyl trimethylammonium, cetyl trimethylammonium, tetradecyl trimethylammonium, dodecyl trimethylammonium, decyl trimethylammonium, octyl trimethylammonium, phenethyl trimethylammonium, benzyl trimethylammonium, phenyl trimethylammonium, benzyl hexadecyl dimethylammonium, benzyl tetradecyl dimethylammonium, benzyl dodecyl dimethylammonium, benzyl decyl dimethylammonium, benzyl octyl dimethylammonium, benzyl tributylammonium, benzyl triethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyl dimethylammonium, tetraethylammonium, and tetramethylammonium. In some embodiments, the organic cation is alkylphosphonium and is selected from tetraphenylphosphonium, dimethyldiphenylphosphonium, methyltriphenoxophosphonium, hexadecyl tributylphosphonium, octyl tributylphosphonium, tetradecyl trihexylphosphonium, tetrakis(hydroxymethyl)phosphonium, tetraoctylphosphonium, tetrabutylphosphonium, and tetramethylphosphonium. In some embodiments, the fluorine-containing ligand is a salt of tetrafluorozincate or dichlorodifluorozincate. In some embodiments, the fluorine-containing ligand is tetrabutylammonium tetrafluorozincate or tetrabutylammonium dichlorodifluorozincate.

[0204] The concentration of the fluorine-containing ligand in the nanostructure composition can be determined by measuring the optical density (OD). The OD can be measured at 450 nm using a cuvette with a 1 cm path length. For the OD 450100 μL of nanostructured composition with OD = 1.5, where the concentration of the fluorine-containing ligand is between about 0.01 mM and about 40 mM, between about 0.01 mM and about 20 mM, between about 0.01 mM and about 10 mM, between about 0.01 mM and about 5 mM, between about 0.01 mM and about 2.5 mM, between about 0.01 mM and about 1.5 mM, between about 0.01 mM and about 1 mM, between about 0.01 mM and about 0.5 mM, between about 0.01 mM and about 0.25 mM, between about 0.25 mM and about 40 mM, between about 0.25 mM and about 20 mM, between about 0.25 mM and about 10 mM, between about 0.25 mM and about 5 mM, between about 0.25 mM and about 2.5 mM, between about 0.25 mM and about 1.5 mM, between about 0.25 mM and about 1.5 mM, between about 0.25 mM and about 1 mM, between about 0.25 mM and about 0.5 mM, between about 0.25 mM and about 0.25 mM, between about 0.5 mM and about 40 mM, between about 0.5 mM and about 20 mM, between about 0.5 mM and about 10 mM, between about 0.5 mM and about 5 mM, between about 0.5 mM and about 2.5 mM, between about 0.5 mM and about 1.5 mM, between about 0.5 mM and about 1 mM, between about 1 mM and about 40 mM, between about 1 mM and about 20 mM, between about 1 mM and about 10 mM, between about 1 mM and about 5 mM, between about 1 mM and about 2.5 mM, between about 1 mM and about 1.5 mM, between about 1.5 mM and about 40 mM, between about 1.5 mM and about 20 mM, between about 1.5 mM and about 10 mM, between about 1.5 mM and about 5 mM, between about 1.5 mM and about 2.5 mM, between about 2.5 mM and about 40 mM, between about 2.5 mM and about 20 mM, between about 2.5 mM and about 10 mM, between about 2.5 mM and about 5 mM mM, between about 5 mM and about 40 mM, between about 5 mM and about 20 mM, between about 5 mM and about 10 mM, between about 10 mM and about 40 mM, between about 10 mM and about 20 mM, or between about 20 mM and about 40 mM. In some embodiments, for OD 450 100 μL of nanostructured composition with OD = 1.5, where the concentration of the fluorine-containing ligand is between about 1 mM and about 12 mM. In some embodiments, for OD 450 100 μL of nanostructured composition with OD = 1.5, where the concentration of the fluorine-containing ligand is about 6 mM.

[0205] In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand bound to the nanostructured composition to zinc atoms in the nanostructured composition is between about 0.1 and about 0.5, between about 0.1 and about 0.4, between about 0.1 and about 0.3, between about 0.1 and about 0.2, between about 0.2 and about 0.5, between about 0.2 and 0.4, between about 0.2 and 0.3, between about 0.3 and 0.5, between about 0.3 and 0.4, or between about 0.4 and 0.5. In some embodiments, the molar ratio of fluorine atoms in the fluorine-containing ligand bound to the nanostructured composition to zinc atoms in the nanostructured composition is about 0.32.

[0206] Solvents and surfactants

[0207] In some embodiments, the nanostructured composition further comprises a solvent.

[0208] In some embodiments, the solvent is selected from: hexane, heptane, octane, toluene, chloroform, N-methylformamide, butanone, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, 1,4-butanediol diacetate, diethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, glyceryl triacetate, heptyl acetate, hexyl acetate, amyl acetate, butyl acetate, ethyl acetate, diethylene glycol butyl methyl ether, diethylene glycol monobutyl ether, di(propylene glycol) dimethyl ether, diethylene glycol ethyl methyl ether, ethylene glycol monobutyl ether, diethylene glycol diethyl ether, methyl ethyl ketone, methyl isobutyl ketone, monomethyl ether ethylene glycol ester, γ-butyrolactone, 3-ethoxy methyl acetate, butyl carbitol, butyl carbitol acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexane, toluene, xylene, isopropyl alcohol, and combinations thereof. In some embodiments, the solvent is selected from hexane, heptane, octane, toluene, chloroform, and N-methylformamide.

[0209] In some embodiments, the solvent is a nonpolar solvent.

[0210] In some embodiments, the nanostructured composition further comprises a surfactant.

[0211] In some embodiments, the surfactant is selected from tetrabutylammonium bromide, tetramethylammonium acetate, didodecyldimethylammonium bromide, dicetyldimethylammonium bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium bromide, didecyldimethylammonium bromide, dioctyldimethylammonium bromide, bis(2-ethylhexyl)dimethylammonium bromide, octadecyltrimethylammonium bromide, oleyltrimethylammonium bromide, cetyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, decyltrimethylammonium bromide, octyltrimethylammonium bromide, phenethyltrimethylammonium bromide, benzyltrimethylammonium bromide, phenyltrimethylammonium bromide, benzylhexadecyldimethylammonium bromide, benzyltetradecyldimethylammonium bromide, benzyldodecyldimethylammonium bromide, benzyldecylldimethylammonium bromide, benzyloctyldimethylammonium bromide, benzyltributylammonium bromide, benzyltriethylammonium bromide, tetrabutylammonium bromide, tetrapropylammonium bromide, diisopropyldimethylammonium bromide, tetraethylammonium bromide, tetramethylammonium bromide, tetraphenylphosphonium bromide, dimethyldiphenylphosphonium bromide, methyltriphenoxyphosphonium bromide, hexadecyltributylphosphonium bromide, octyltributylphosphonium bromide, tetradecyltrihexylphosphonium bromide, tetrakis(hydroxymethyl)phosphonium bromide, tetraoctylphosphonium bromide, tetrabutylphosphonium bromide, tetramethylphosphonium bromide, dodecylammonium bromide, didodecyldimethylammonium chloride, dicetyldimethylammonium chloride, ditetradecyldimethylammonium chloride, didodecyldimethylammonium chloride, didecyldimethylammonium chloride, dioctyldimethylammonium chloride, bis(2-ethylhexyl)dimethylammonium chloride, octadecyltrimethylammonium chloride, oleyltrimethylammonium chloride, cetyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, decyltrimethylammonium chloride, octyltrimethylammonium chloride, phenethyltrimethylammonium chloride, benzyltrimethylammonium chloride, phenyltrimethylammonium chloride, benzylhexadecyldimethylammonium chloride, benzyltetradecyldimethylammonium chloride, benzyldodecyldimethylammonium chloride, benzyldecylldimethylammonium chloride, benzyloctyldimethylammonium chloride, benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium chloride, tetrapropylammonium chloride, diisopropyldimethylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, tetraphenylphosphonium chloride, dimethyldiphenylphosphonium chloride, methyltriphenoxyphosphonium chloride, hexadecyltributylphosphonium chloride, octyltributylphosphonium chloride, tetradecyltrihexylphosphonium chloride, tetrakis(hydroxymethyl)phosphonium chloride, tetraoctylphosphonium chloride, tetrabutylphosphonium chloride, tetramethylphosphonium chloride, and dodecylammonium chloride.

[0212] Methods for Preparing Nanostructured Compounds and Ligand Exchange

[0213] In some embodiments, the present disclosure relates to a ligand exchange method for replacing a first ligand on a nanostructure with a second ligand.

[0214] In some embodiments, the first ligand is a fatty acid selected from lauric acid, caproic acid, myristic acid, palmitic acid, stearic acid, and oleic acid. In some embodiments, the first ligand is an organophosphine or organophosphine oxide selected from trioctylphosphine oxide, trioctylphosphine, diphenylphosphine, triphenylphosphine oxide, and tributylphosphine oxide. In some embodiments, the first ligand is an amine selected from dodecylamine, oleylamine, hexadecylamine, dioctylamine, and octadecylamine. In some embodiments, the first ligand is tributylphosphine, oleic acid, or zinc oleate.

[0215] In some embodiments, the second ligand is a fluorine-containing ligand. In some embodiments, the fluorine-containing ligand comprises an anion including fluozincate and an inorganic cation. In some embodiments, the inorganic cation includes a metal ion. In some embodiments, the cation includes a potassium ion. In some embodiments, the fluorine-containing ligand comprises an anion including fluozincate and an organic cation. In some embodiments, the organic cation is selected from tetraalkylammonium, alkylphosphonium, formamidinium, guanidinium, imidazolium, and pyridinium. In some embodiments, the cation is tetraalkylammonium and is selected from dioctadecyldimethylammonium, dihexadecyldimethylammonium, ditetradecyldimethylammonium, didodecyldimethylammonium, didecyldimethylammonium, dioctyldimethylammonium, bis(ethylhexyl)dimethylammonium, octadecyltrimethylammonium, oleyltrimethylammonium, hexadecyltrimethylammonium, tetradecyltrimethylammonium, dodecyltrimethylammonium, decyltrimethylammonium, octyltrimethylammonium, phenethyltrimethylammonium, benzyltrimethylammonium, phenyltrimethylammonium, benzylhexadecyldimethylammonium, benzyltetradecyldimethylammonium, benzyl dodecyldimethylammonium, benzyl decyldimethylammonium, benzyl octyldimethylammonium, benzyl tributylammonium, benzyltriethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyldimethylammonium, tetraethylammonium, and tetramethylammonium. In some embodiments, the cation is alkylphosphonium and is selected from tetraphenylphosphonium, dimethyldiphenylphosphonium, methyltriphenoxophosphonium, hexadecyltributylphosphonium, octyltributylphosphonium, tetradecyltrihexylphosphonium, tetrakis(hydroxymethyl)phosphonium, tetraoctylphosphonium, tetrabutylphosphonium, and tetramethylphosphonium. In some embodiments, the fluorine-containing ligand is a salt of tetrafluozincate or dichlorodifluozincate. In some embodiments, the fluorine-containing ligand is tetrabutylammonium tetrafluozincate or tetrabutylammonium dichlorodifluozincate.

[0216] In some embodiments, the second ligand is a fluoride anion.

[0217] In some embodiments, the molar ratio of the first ligand to the fluorinated ligand is between about 1:1 and about 1:8, about 1:1 and about 1:7, 1:1 and about 1:6, about 1:1 and about 1:5, about 1:1 and about 1:4, about 1:1 and about 1:3, about 1:1 and about 1:2, about 1:2 and about 1:8, about 1:2 and about 1:7, about 1:2 and about 1:6, about 1:2 and about 1:5, about 1:2 and about 1:4, about 1:2 and about 1:3, about 1:3 and about 1:8, about 1:3 and about 1:7, about 1:3 and about 1:6, about 1:3 and about 1:5, about 1:3 and about 1:4, about 1:4 and about 1:8, about 1:4 and about 1:7, about 1:4 and about 1:6, about 1:4 and about 1:5, about 1:5 and about 1:8, about 1:5 and about 1:7, about 1:5 and about 1:6, about 1:6 and about 1:8, about 1:6 and about 1:7, or about 1:7 and about 1:8. In some embodiments, the molar ratio of the first ligand to the fluorinated ligand is between about 1:1 and about 1:3.

[0218] In some embodiments, the molar ratio of the first ligand to the fluoride anion is between about 1:1 and about 1:8, about 1:1 and about 1:7, 1:1 and about 1:6, about 1:1 and about 1:5, about 1:1 and about 1:4, about 1:1 and about 1:3, about 1:1 and about 1:2, about 1:2 and about 1:8, about 1:2 and about 1:7, about 1:2 and about 1:6, about 1:2 and about 1:5, about 1:2 and about 1:4, about 1:2 and about 1:3, about 1:3 and about 1:8, about 1:3 and about 1:7, about 1:3 and about 1:6, about 1:3 and about 1:5, about 1:3 and about 1:4, about 1:4 and about 1:8, about 1:4 and about 1:7, about 1:4 and about 1:6, about 1:4 and about 1:5, about 1:5 and about 1:8, about 1:5 and about 1:7, about 1:5 and about 1:6, about 1:6 and about 1:8, about 1:6 and about 1:7, or about 1:7 and about 1:8. In some embodiments, the molar ratio of the first ligand to the fluoride anion is between about 1:1 and about 1:3.

[0219] The percentage of the first ligand replaced by the fluorinated ligand can be determined by 11H NMR measurement. In some embodiments, the molar percentage of the first ligand replaced by the fluorinated ligand is between about 20% and about 100%, between about 20% and about 80%, between about 20% and about 60%, between about 20% and about 40%, between about 25% and about 100%, between about 25% and about 80%, between about 25% and about 60%, between about 25% and about 40%, between about 30% and about 100%, between about 30% and about 80%, between about 30% and about 60%, between about 30% and about 40%, between about 40% and about 100%, between about 40% and about 80%, between about 40% and about 60%, between about 60% and about 100%, between about 60% and about 80%, or between about 80% and about 100%. In some embodiments, the molar percentage of the first ligand replaced by the fluorinated ligand is about 90%. In some embodiments, the molar percentage of the first ligand replaced by the fluorinated ligand is about 100%.

[0220] The percentage of the first ligand replaced by fluoride anions can be determined by 1 1H NMR measurement. In some embodiments, the molar percentage of the first ligand replaced by fluoride anions is between about 20% and about 100%, between about 20% and about 80%, between about 20% and about 60%, between about 20% and about 40%, between about 25% and about 100%, between about 25% and about 80%, between about 25% and about 60%, between about 25% and about 60%, between about 25% and about 40%, between about 30% and about 100%, between about 30% and about 80%, between about 30% and about 60%, between about 30% and about 40%, between about 40% and about 100%, between about 40% and about 80%, between about 40% and about 60%, between about 60% and about 100%, between about 60% and about 80%, or between about 80% and about 100%. In some embodiments, the molar percentage of the first ligand replaced by fluoride anions is about 90%. In some embodiments, the molar percentage of the first ligand replaced by fluoride anions is about 100%.

[0221] The percentage of the fluorinated ligand bound to the nanostructures in a population of nanostructures can be determined by 19 19F NMR measurement, where the bound ligand is calculated using the formula: (bound fluorinated ligand) / (bound + free fluorinated ligand).

[0222] In some embodiments, the molar percentage of the fluorinated ligand bound to the nanostructure is between about 20% and about 100%, between about 20% and about 80%, between about 20% and about 60%, between about 20% and about 40%, between about 25% and about 100%, between about 25% and about 80%, between about 25% and about 60%, between about 25% and about 40%, between about 30% and about 100%, between about 30% and about 80%, between about 30% and about 60%, between about 30% and about 40%, between about 40% and about 100%, between about 40% and about 80%, between about 40% and about 60%, between about 60% and about 100%, between about 60% and about 80%, or between about 80% and about 100%.

[0223] In some embodiments, the molar percentage of the fluoride anion bound to the nanostructure is between about 20% and about 100%, between about 20% and about 80%, between about 20% and about 60%, between about 20% and about 40%, between about 25% and about 100%, between about 25% and about 80%, between about 25% and about 60%, between about 25% and about 40%, between about 30% and about 100%, between about 30% and about 80%, between about 30% and about 60%, between about 30% and about 40%, between about 40% and about 100%, between about 40% and about 80%, between about 40% and about 60%, between about 60% and about 100%, between about 60% and about 80%, or between about 80% and about 100%.

[0224] In some embodiments, the present disclosure relates to a method of preparing a nanostructured composition, the method comprising: (a) providing at least one population of nanostructures; and (b) mixing at least one fluorinated ligand with the nanostructures of (a); or (b') mixing a tetraalkylammonium fluoride with the nanostructures of (a) to produce a nanostructured composition. In some embodiments, the fluorinated ligand in (b) comprises an anion including fluozincate and an inorganic cation. In some embodiments, the inorganic cation comprises a metal ion. In some embodiments, the cation comprises a potassium ion. In some embodiments, the fluorinated ligand in (b) is selected from fluozincate, tetrafluoroborate, and hexafluorophosphate.

[0225] In some embodiments, the mixing in (b’) is with a tetraalkylammonium fluoride, wherein the tetraalkylammonium is selected from dioctadecyl dimethylammonium, dihexadecyl dimethylammonium, ditetradecyl dimethylammonium, didodecyl dimethylammonium, didecyl dimethylammonium, dioctyl dimethylammonium, bis(ethylhexyl) dimethylammonium, octadecyl trimethylammonium, oleyl trimethylammonium, cetyl trimethylammonium, tetradecyl trimethylammonium, dodecyl trimethylammonium, decyl trimethylammonium, octyl trimethylammonium, phenethyl trimethylammonium, benzyl trimethylammonium, phenyl trimethylammonium, benzyl hexadecyl dimethylammonium, benzyl tetradecyl dimethylammonium, benzyl dodecyl dimethylammonium, benzyl decyl dimethylammonium, benzyl octyl dimethylammonium, benzyl tributylammonium, benzyl triethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyl dimethylammonium, tetraethylammonium, and tetramethylammonium.

[0226] In some embodiments, the tetraalkylammonium fluoride is tetra-C 1-6 alkylammonium fluoride. In some embodiments, the tetraalkylammonium fluoride is tetrabutylammonium fluoride. In some embodiments, the mixing in (b) or (b’) is carried out at a temperature between about 10°C and about 100°C, between about 10°C and about 80°C, between about 10°C and about 60°C, between about 10°C and about 40°C, between about 10°C and about 20°C, between about 20°C and about 100°C, between about 20°C and about 80°C, between about 20°C and about 60°C, between about 20°C and about 40°C, between about 40°C and about 100°C, between about 40°C and about 80°C, between about 40°C and about 60°C, between about 60°C and about 100°C, between about 60°C and about 80°C, or between about 80°C and about 100°C.

[0227] In some embodiments, the method further comprises (c) mixing at least one organic cation with the nanostructure of (b) or (b’) to produce a nanostructure composition. In some embodiments, the organic cation is selected from tetraalkylammonium, alkylphosphonium, formamidinium, guanidinium, imidazolium, and pyridinium. In some embodiments, the organic cation is tetraalkylammonium and is selected from dioctadecyldimethylammonium, distearyldimethylammonium, ditetradecyldimethylammonium, didodecyldimethylammonium, didecyldimethylammonium, dioctyldimethylammonium, bis(ethylhexyl)dimethylammonium, octadecyltrimethylammonium, oleyltrimethylammonium, cetyltrimethylammonium, tetradecyltrimethylammonium, dodecyltrimethylammonium, decyltrimethylammonium, octyltrimethylammonium, phenethyltrimethylammonium, benzyltrimethylammonium, phenyltrimethylammonium, benzylhexadecyldimethylammonium, benzyltetradecyldimethylammonium, benzyldodecyldimethylammonium, benzyldecylmethylammonium, benzyloctyldimethylammonium, benzyltributylammonium, benzyltriethylammonium, tetrabutylammonium, tetrapropylammonium, diisopropyldimethylammonium, tetraethylammonium, and tetramethylammonium. In some embodiments, the organic cation is alkylphosphonium and is selected from tetraphenylphosphonium, dimethyldiphenylphosphonium, methyltriphenoxophosphonium, hexadecyltributylphosphonium, octyltributylphosphonium, tetradecyltrihexylphosphonium, tetrakis(hydroxymethyl)phosphonium, tetraoctylphosphonium, tetrabutylphosphine, and tetramethylphosphonium.

[0228] In some embodiments, the mixing in (c) is carried out at a temperature between about 10 °C and about 100 °C, between about 10 °C and about 80 °C, between about 10 °C and about 60 °C, between about 10 °C and about 40 °C, between about 10 °C and about 20 °C, between about 20 °C and about 100 °C, between about 20 °C and about 80 °C, between about 20 °C and about 60 °C, between about 20 °C and about 40 °C, between about 40 °C and about 100 °C, between about 40 °C and about 80 °C, between about 40 °C and about 60 °C, between about 60 °C and about 100 °C, between about 60 °C and about 80 °C, or between about 80 °C and about 100 °C.

[0229] In some embodiments, the method further comprises (d) dispersing the nanostructure of (c) in a nonpolar solvent. In some embodiments, the nonpolar solvent is selected from hexane, heptane, octane, toluene, and chloroform.

[0230] Optical properties of nanostructures functionalized with fluorine-containing ligands or fluoride anions

[0231] In some embodiments, a core / shell nanostructure functionalized with a fluorine-containing ligand or a fluoride anion can exhibit a high photoluminescence quantum yield. In some embodiments, a core / shell nanostructure functionalized with a fluorine-containing ligand or a fluoride anion can exhibit a photoluminescence quantum yield between about 60% and about 99%, between about 60% and about 95%, between about 60% and about 90%, between about 60% and about 85%, between about 60% and about 80%, between about 60% and about 70%, between about 70% and about 99%, 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 80% and about 99%, between about 80% and about 95%, between about 80% and about 90%, between about 80% and about 85%, between about 85% and about 99%, between about 85% and about 95%, between about 80% and about 85%, between about 85% and about 99%, between about 85% and about 90%, between about 90% and about 99%, between about 90% and about 95%, or between about 95% and about 99%. In some embodiments, a core / shell nanostructure functionalized with a fluorine-containing ligand or a fluoride anion can exhibit a photoluminescence quantum yield between about 60% and about 99%. In some embodiments, a core / shell nanostructure functionalized with a fluorine-containing ligand or a fluoride anion can exhibit a photoluminescence quantum yield between about 70% and about 90%.

[0232] The photoluminescence spectrum of a core / shell nanostructure functionalized with a fluorine-containing ligand or a fluoride anion can substantially cover any desired portion of the spectrum. In some embodiments, the photoluminescence spectrum of the core / shell nanostructure can have an emission maximum between about 300 nm and about 750 nm, between about 300 nm and about 650 nm, between about 300 nm and about 550 nm, between about 300 nm and about 450 nm, between about 450 nm and about 750 nm, between about 450 nm and about 650 nm, between about 450 nm and about 550 nm, between about 450 nm and about 750 nm, between about 450 nm and about 650 nm, between about 450 nm and about 550 nm, between about 550 nm and about 750 nm, between about 550 nm and about 650 nm, or between about 650 nm and about 750 nm.

[0233] In some embodiments, the core / shell nanostructures emit in the red range. In some embodiments, the nanostructure composition exhibits a photoluminescence peak wavelength between about 600 nm and about 650 nm, between about 600 nm and about 640 nm, between about 600 nm and about 630 nm, between about 600 nm and about 620 nm, between about 600 nm and about 610 nm, between about 610 nm and about 650 nm, between about 610 nm and about 640 nm, between about 610 nm and about 630 nm, between about 610 nm and about 620 nm, between about 620 nm and about 650 nm, between about 620 nm and about 640 nm, between about 620 nm and about 630 nm, between about 630 nm and about 650 nm, between about 630 nm and about 640 nm, or between about 640 nm and about 650 nm. In some embodiments, the core / shell nanostructures include a core containing indium.

[0234] In some embodiments, the core / shell nanostructures emit in the green range. In some embodiments, the nanostructure composition exhibits a photoluminescence peak wavelength between about 510 nm and about 560 nm, between about 510 nm and about 550 nm, between about 510 nm and about 540 nm, between about 510 nm and about 530 nm, between about 510 nm and about 520 nm, between about 520 nm and about 560 nm, between about 520 nm and about 550 nm, between about 520 nm and about 540 nm, between about 520 nm and about 530 nm, between about 530 nm and about 560 nm, between about 530 nm and about 550 nm, between about 530 nm and about 540 nm, between about 540 nm and about 560 nm, between about 540 nm and about 550 nm, or between about 550 nm and about 560 nm. In some embodiments, the core / shell nanostructures emit in the red range. In some embodiments, the nanostructure composition exhibits a photoluminescence peak wavelength between about 525 nm and about 535 nm. In some embodiments, the core / shell nanostructures include a core containing zinc.

[0235] In some embodiments, the core / shell nanostructures emit in the blue, indigo, violet, and / or ultraviolet ranges. In some embodiments, the nanostructure composition exhibits a photoluminescence peak wavelength between about 420 nm and about 470 nm, between about 420 nm and about 460 nm, between about 420 nm and about 450 nm, between about 420 nm and about 440 nm, between about 420 nm and about 430 nm, between about 430 nm and about 470 nm, between about 430 nm and about 460 nm, between about 430 nm and about 450 nm, between about 430 nm and about 440 nm, between about 440 nm and about 470 nm, between about 440 nm and about 460 nm, between about 440 nm and about 450 nm, between about 450 nm and about 470 nm, between about 450 nm and about 460 nm, or between about 460 nm and about 470 nm. In some embodiments, the nanostructure composition exhibits a photoluminescence peak wavelength between about 450 nm and about 460 nm. In some embodiments, the core / shell nanostructures include a core containing zinc.

[0236] The size distribution of core / shell nanostructures functionalized with a fluorine-containing ligand or fluoride anion can be relatively narrow. In some embodiments, the photoluminescence spectrum of a population of core / shell nanostructures functionalized with a fluorine-containing ligand or fluoride anion can have a full width at half maximum between about 10 nm and about 60 nm, between about 10 nm and about 40 nm, between about 10 nm and about 30 nm, between about 10 nm and about 20 nm, between about 20 nm and about 60 nm, between about 20 nm and about 40 nm, between about 20 nm and about 30 nm, between about 30 nm and about 60 nm, between about 30 nm and about 40 nm, or between about 40 nm and about 60 nm. In some embodiments, the photoluminescence spectrum of a population of core / shell nanostructures functionalized with a fluorine-containing ligand or fluoride anion can have a full width at half maximum between about 35 nm and about 45 nm.

[0237] Increased colloidal stability of nanostructures functionalized with a fluorine-containing ligand or fluoride anion

[0238] In some embodiments, the nanostructures are stored as a colloidal suspension in a solvent. A colloid is a mixture in which a substance with microscopically dispersed insoluble particles is suspended within another substance as a whole. Colloidal stability can be determined by measuring the number of insoluble particles that remain suspended at equilibrium. Colloidal stability can be hindered by the aggregation or deposition of insoluble microparticles.

[0239] Passivating nanostructures with fluorine-containing ligands or fluoride anions provides increased colloidal stability and allows for long-term storage of the nanoparticles. In some embodiments, nanostructures functionalized with fluorine-containing ligands or fluoride anions can be stored at temperatures between about 10 °C and about 90 °C for about 1 minute to about 3 years, about 1 minute to about 12 months, about 1 minute to about 6 months, about 1 minute to about 3 months, about 1 minute to about 1 month, about 1 minute to about 15 days, about 1 minute to about 1 day, about 1 day to about 3 years, about 1 day to about 12 months, about 1 day to about 6 months, about 1 day to about 3 months, about 1 day to about 1 month, about 1 day to about 7 days, about 1 day to about 15 days, about 1 day to about 7 days, about 1 day to about 2 days, about 2 days to about 3 years, about 2 days to about 12 months, about 2 days to about 6 months, about 2 days to about 3 months, about 2 days to about 1 month, about 2 days to about 15 days, about 2 days to about 7 days, about 7 days to about 3 years, about 7 days to about 12 months, about 7 days to about 6 months, about 7 days to about 3 months, about 7 days to about 1 month, about 7 days to about 15 days to about 3 years, about 15 days to about 12 months, about 15 days to about 6 months, about 15 days to about 3 months, about 15 days to about 1 month, about 1 month to about 1 month to about 3 years to about 1 month to about 12 months, about 1 month to about 6 months, about 1 month to about 3 months, about 3 months to about 3 years, about 3 months to about 12 months, about 3 months to about 6 months, about 6 months to about 3 years, about 6 months to about 12 months, or about 12 months to about 3 years.

[0240] In some embodiments, nanostructures functionalized with fluorine-containing ligands or fluoride anions can be stored at temperatures between about 30 °C and about 90 °C for about 1 minute to about 3 years, about 1 minute to about 12 months, about 1 minute and about 6 months, about 1 minute and about 3 months, about 1 minute to about 1 month, about 1 minute to about 15 days, about 1 minute to about 1 day, about 1 day to about 3 years, about 1 day to about 12 months, about 1 day to about 6 months, about 1 day to about 3 months, about 1 day to about 1 month, about 1 day to about 7 days, about 1 day to about 15 days, about 1 day to about 7 days, about 1 day to about 2 days, about 2 days to about 3 years, about 2 days to about 12 months, about 2 days to about 6 months, about 2 days to about 3 months, about 2 days to about 1 month, about 2 days to about 15 days, about 2 days to about 7 days, about 7 days to about 3 years, about 7 days to about 12 months, about 7 days to about 6 months, about 7 days to about 3 months, about 7 days to about 1 month, about 7 days to about 15 days to about 3 years, about 15 days to about 12 months, about 15 days to about 6 months, about 15 days to about 3 months, about 15 days to about 1 month, about 1 month to about 1 month to about 3 years to about 1 month to about 12 months, about 1 month and about 6 months, about 1 month and about 3 months, about 3 months and about 3 years, about 3 months and about 12 months, about 3 months and about 6 months, about 6 months and about 3 years, about 6 months and about 12 months, or about 12 months and about 3 years.

[0241] Nanostructure film

[0242] In some embodiments, core / shell nanostructures functionalized with fluorine-containing ligands or fluoride anions are introduced into the nanostructured film. In some embodiments, the nanostructured film comprises at least one population of nanostructures, wherein the nanostructures include: (a) at least one population of nanostructures, the nanostructures including a core and at least one shell; and (b) at least one fluorine-containing ligand bound to the surface of the nanostructures; or (b') fluoride anions bound to the surface of the nanostructures; wherein the fluorine-containing ligand is selected from fluozincate, tetrafluoroborate, and hexafluorophosphate. In some embodiments, the nanostructured film comprises from one to five populations of nanostructures. In some embodiments, the nanostructured film comprises one population of nanostructures.

[0243] In some embodiments, the nanostructured film further comprises at least one organic resin. In some embodiments, the nanostructured film further comprises an organic resin. In some embodiments, the nanostructured film further comprises from one to five organic resins. In some embodiments, core / shell nanostructures functionalized with fluorine-containing ligands or fluoride anions are embedded in a matrix comprising at least one organic resin. In some embodiments, the at least one organic resin is a thermosetting resin or a UV-curable resin. In some embodiments, the at least one organic resin is a UV-curable resin. As used herein, the term "embedded" is used to indicate that the nanostructures are enclosed or encapsulated within the matrix material of the majority of the components that make up the matrix. In some embodiments, the nanostructures are uniformly distributed throughout the matrix material. In some embodiments, the nanostructures are distributed according to a uniformity distribution function specific to the application.

[0244] In some embodiments, the nanostructures can include a uniform population having dimensions that emit in the blue visible wavelength spectrum, the green visible wavelength spectrum, or the red visible wavelength spectrum. In some embodiments, the nanostructures can include a first population of nanostructures having dimensions that emit in the blue visible wavelength spectrum, a second population of nanostructures having dimensions that emit in the green visible wavelength spectrum, and a third population of nanostructures having dimensions that emit in the red visible wavelength spectrum.

[0245] The matrix material can be any suitable host matrix material capable of accommodating the nanostructures. The suitable matrix material can be chemically and optically compatible with the nanostructures and any surrounding packaging material or layer used to apply the nanostructure film to the device. The suitable matrix material can include a non-yellowing optical material that is transparent to both the primary color light and the secondary light, thereby allowing both the primary color light and the secondary light to propagate through the matrix material. The matrix material can include polymers as well as organic and inorganic oxides. The polymers suitable for the matrix material can be any polymers known to those of ordinary skill in the art that can be used for such purposes. The polymers can be substantially translucent or substantially transparent. The matrix material can include, but is not limited to, epoxy resins, acrylates, norbornene, polyethylene, poly(vinyl butyral): poly(vinyl acetate), polyureas, polyurethanes; silicones and silicone derivatives, including but not limited to aminosilicones (AMS), polydimethylphenylsiloxane, polydiphenylalkylsiloxane, polydiphenylsiloxane, polydialkylsiloxane, silsesquioxanes, fluorosilicones, and vinyl- and hydride-substituted siloxanes; acrylic polymers and copolymers formed from monomers including but not limited to methyl methacrylate, butyl methacrylate, and lauryl methacrylate; styrene-based polymers such as polystyrene, aminopolystyrene (APS), and poly(acrylonitrile-ethylene-styrene) (AES); polymers crosslinked with bifunctional monomers such as divinylbenzene; crosslinking agents suitable for crosslinking ligand materials, epoxides that combine with ligand amines such as APS or polyethyleneimine ligand amines to form epoxy resins, and so on.

[0246] In some embodiments, the matrix material includes scattering microbeads, such as TiO 2 microbeads, ZnS microbeads, or glass microbeads, which can improve the light conversion efficiency of the nanostructure film. In some embodiments, the matrix material can include light-blocking elements.

[0247] In some embodiments, the matrix material can have low oxygen and moisture permeability, exhibit high light and chemical stability, exhibit a favorable refractive index, and adhere to the outer surface of the nanostructures, thereby providing an airtight seal to protect the nanostructures. In another embodiment, the matrix material can be cured by UV or thermal curing methods to facilitate roll-to-roll processing.

[0248] In some embodiments, the nanostructure film can be formed by mixing the nanostructures in a polymer (such as a photoresist) and casting the nanostructure-polymer mixture on a substrate, mixing the nanostructures with monomers and polymerizing them together, mixing the nanostructures in a sol-gel to form an oxide, or any other method known to those skilled in the art.

[0249] In some embodiments, the formation of the nanostructured film can include a film extrusion process. The film extrusion process can include forming a homogeneous mixture of a matrix material and a core-shell nanostructure coated with a barrier layer (e.g., a nanostructure functionalized with a fluorinated ligand or a fluoride anion), and introducing the homogeneous mixture into a top-mounted hopper feeding into an extruder. In some embodiments, the homogeneous mixture can be in the form of pellets. The film extrusion process can further include extruding the nanostructured film from a slot die and passing the extruded nanostructured film through cold rolling rollers. In some embodiments, the thickness of the extruded nanostructured film can be less than about 75 μm, e.g., in the range of about 70 μm to about 40 μm, about 65 μm to about 40 μm, about 60 μm to about 40 μm, or about 50 μm to about 40 μm. In some embodiments, the thickness of the nanostructured film is less than about 10 μm. In some embodiments, the formation of the nanostructured film can optionally include a second process followed by the film extrusion process. The second process can include processes such as coextrusion, thermoforming, vacuum forming, plasma treatment, molding, and / or embossing to provide a texture to the top surface of the nanostructured film layer. The textured top surface nanostructured film can help improve, for example, the defined optical diffusion properties and / or the defined angular optical emission properties of the nanostructured film.

[0250] Molded article

[0251] In some embodiments, the present disclosure provides a molded article comprising any of the nanostructures disclosed herein. In some embodiments, the present disclosure provides a molded article comprising any of the nanostructured films disclosed herein. In some embodiments, the present disclosure provides a molded article comprising nanostructures, the nanostructures comprising: (a) at least one population of nanostructures comprising a core and at least one shell; and (b) at least one fluorinated ligand bound to the surface of the nanostructures; or (b') a fluoride anion bound to the surface of the nanostructures; wherein the fluorinated ligand is selected from fluozincate, tetrafluoroborate, and hexafluorophosphate. In some embodiments, the nanostructures are quantum dots.

[0252] In some embodiments, the molded article is a film, a substrate for a display device, or a light-emitting diode. In some embodiments, the molded article is an electroluminescent device.

[0253] In some embodiments, the molded article comprises a quantum dot layer. In some embodiments, the quantum dot layer comprises a patterned quantum dot layer.

[0254] In some embodiments, the quantum dot layer has a thickness between about 1 μm and about 25 μm. In some embodiments, the quantum dot layer has a thickness between about 5 μm and about 25 μm. In some embodiments, the quantum dot layer has a thickness between about 10 μm and about 12 μm.

[0255] Fabricating a nanostructured layer

[0256] In some embodiments, the nanostructured layer can be embedded in a polymer matrix. As used herein, the term "embedded" is used to mean that a population of nanostructures is surrounded or encapsulated by a polymer that constitutes the majority of the components of the matrix. In some embodiments, at least one population of nanostructures is suitably uniformly distributed throughout the matrix. In some embodiments, at least one population of nanostructures is distributed according to an application-specific distribution. In some embodiments, the nanostructures are mixed in the polymer and applied to the surface of a substrate.

[0257] In some embodiments, a nanostructured composition is deposited to form a nanostructured layer. In some embodiments, the nanostructured composition can be deposited by any suitable method known in the art, including but not limited to spray painting, spraying, solvent spraying, wet coating, adhesive coating, spin coating, tape coating, roll coating, flow coating, inkjet vapor jetting, drop casting, blade coating, fog deposition, or combinations thereof. The nanostructured composition can be directly coated on a desired layer of a substrate. Alternatively, the nanostructured composition can form a solid layer as a stand-alone element and is subsequently applied to the substrate. In some embodiments, the nanostructured composition can be deposited on one or more barrier layers.

[0258] In some embodiments, the nanostructured layer is cured after deposition. Suitable curing methods include photocuring, such as UV curing, and thermal curing. Conventional laminate film processing methods, tape coating methods, and / or roll-to-roll manufacturing methods can be used to form the nanostructured layer.

[0259] Spin coating

[0260] In some embodiments, the nanostructure composition is deposited onto a substrate using spin coating. In spin coating, a small amount of material is typically deposited at the center of the substrate loaded onto a machine called a spinner, which is fixed by vacuum. A high-speed rotation is applied to the substrate by the spinner, which induces a centripetal force to spread the material from the center of the substrate to the edge. When most of the material is spun off, a certain amount remains on the substrate and forms a thin film of the material on the surface as the rotation continues. The final thickness of the film is determined by the properties of the deposited material and the substrate, in addition to the parameters selected for the spinning process, such as the rotation speed, acceleration, and rotation time. The spin coating conditions required to achieve a controlled thickness are highly dependent on the viscosity and temperature of the deposited material. In some embodiments, a rotation speed of about 1500 rpm to about 6000 rpm is used, and the rotation time is about 10 - 60 seconds.

[0261] Mist deposition

[0262] In some embodiments, the nanostructure composition is deposited onto a substrate using mist deposition. Mist deposition occurs at room temperature and atmospheric pressure, allowing for precise control of the film thickness by varying the process conditions. During mist deposition, the liquid source material is converted into a very fine mist and is transported to the deposition chamber by nitrogen gas. The mist is then attracted to the wafer surface by a high-voltage potential between a field screen and a wafer chuck. Once the droplets converge on the wafer surface, the wafer is removed from the chamber and thermally cured to allow the solvent to evaporate. The liquid precursor is a mixture of a solvent and the material to be deposited. It is carried by pressurized nitrogen gas to an atomizer. Price, S.C., et al., "Formation of Ultra-Thin Quantum Dot Films by Mist Deposition," ESC Transactions 11:89 - 94 (2007).

[0263] Spray coating

[0264] In some embodiments, the nanostructure composition is deposited onto a substrate using spray coating. Typical spray coating equipment includes a nozzle, an atomizer, a precursor solution, and a carrier gas. In the spray deposition process, the precursor solution is fragmented into micro-sized droplets by the carrier gas or by atomization (e.g., ultrasonic, pneumatic, or electrostatic). With the help of the carrier gas, the droplets emerging from the atomizer are accelerated towards the substrate surface by the nozzle, and the carrier gas is controlled and adjusted as needed. The relative movement between the nozzle and the substrate is defined by design for the purpose of achieving complete coverage on the substrate.

[0265] In some embodiments, the application of the nanostructure composition also includes a solvent. In some embodiments, the solvent used for applying 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, D 2O, 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 mixtures thereof.

[0266] In some embodiments, the nanostructured composition is thermally cured to form a nanostructured layer. In some embodiments, UV light is used to cure the composition. In some embodiments, the nanostructured composition is directly coated on the barrier layer of the nanostructured film, and then an additional barrier layer is deposited on the nanostructured layer to produce a nanostructured 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, a support substrate can be used under the barrier film. Additionally, it is preferred to deposit one or more barrier layers on the nanostructured layer to seal the material between the top and bottom barrier layers. Appropriately, the barrier layer can be deposited as a laminated film and optionally sealed or further processed, and then the nanostructured film is introduced into a specific lighting device. As will be understood by those of ordinary skill in the art, the nanostructured composition deposition process can include additional or varying components. Such embodiments will allow for on-line process adjustment of the nanostructured emission characteristics - such as brightness and color (e.g., to adjust the white point of the quantum dot film) as well as the nanostructured film thickness and other characteristics. In addition, these embodiments will allow for periodic testing of the properties of the nanostructured film during production, as well as any necessary toggling to achieve precise nanostructured film properties. Such testing and adjustment can also be achieved without changing the mechanical configuration of the processing line, as computer programs can be used to electronically vary the corresponding amounts of the mixtures used to form the nanostructured film.

[0267] Barrier layer

[0268] In some embodiments, the molded article includes one or more barrier layers disposed on one or both sides of the nanostructured layer. Suitable barrier layers protect the nanostructured layer and the molded article from environmental conditions such as high temperature, oxygen, and moisture. Suitable barrier materials include non-yellowing, transparent optical materials that are hydrophobic, chemically and mechanically compatible with the molded article, exhibit light and chemical stability, and can withstand high temperatures. In some embodiments, the one or more barrier layers are index-matched to the molded article. In some embodiments, the matrix material of the molded article and the one or more adjacent barrier layers are index-matched to have similar refractive indices such that most of the light transmitted through the barrier layer to the molded article is transmitted from the barrier layer into the nanostructured layer. This refractive index matching reduces optical losses at the interface between the barrier and the matrix material.

[0269] The barrier layer is a suitable solid material and can be a cured liquid, gel, or polymer. The barrier layer can comprise flexible or non-flexible materials, depending on the specific application. The barrier layer is preferably a planar layer and can include any suitable shape and surface area configuration, depending on the particular lighting application. In some embodiments, the one or more barrier layers will be compatible with lamination film processing techniques whereby the nanostructured layer is disposed on at least a first barrier layer and at least a second barrier layer is disposed on the nanostructured layer on the opposite side of the nanostructured layer to form a molded article according to one embodiment. Suitable barrier materials include any suitable barrier materials known in the art. In some embodiments, 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 oxide, titanium oxide, or aluminum oxide (e.g., SiO 2 , Si 2 O 3 , TiO 2 or Al 2 O 3); and suitable combinations thereof. Preferably, each barrier layer of the molded article comprises at least 2 layers, which comprise different materials or compositions, such that the multi-layer barrier eliminates or reduces pinhole defect alignment in the barrier layer, thereby providing an effective barrier against oxygen and moisture permeation into the nanostructured layer. The nanostructured layer can comprise any suitable material or combination of materials and any suitable number of barrier layers on either or both sides of the nanostructured layer. The material, thickness, and number of the 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 molded article. In a preferred embodiment, each barrier layer comprises a laminate film, preferably a bilayer laminate film, wherein the thickness of each barrier layer is thick enough to eliminate wrinkling in a roll-to-roll or laminate manufacturing process. The number or thickness of the barriers can further depend on the legal toxicity guidelines in the embodiment, where the nanostructure contains heavy metals or other toxic materials, which may require more or thicker barrier layers. Other considerations for the barriers include cost, availability, and mechanical strength.

[0270] In some embodiments, the nanostructured film comprises two or more barrier layers adjacent to each side of the nanostructured layer, e.g., two or three layers on each side or two barrier layers on each side of the nanostructured layer. In some embodiments, each barrier layer comprises a thin glass sheet, e.g., a glass sheet having a thickness of about 100 μm, 100 μm or less, or 50 μm or less.

[0271] Each barrier layer of the molded article can have any suitable thickness, which will depend on the specific requirements and characteristics of the lighting device and application, as well as the individual film components, e.g., the barrier layer and the nanostructured layer, as will be understood by one of ordinary skill in the art. In some embodiments, the thickness of each barrier layer can be 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 certain embodiments, the barrier layer comprises an oxide coating, which can comprise materials such as silica, titanium oxide, and aluminum oxide (e.g., SiO 2 , Si 2 O 3 , TiO 2 or Al 2 O 3 ). The thickness of the oxide coating can be about 10 μm or less, 5 μm or less, 1 μm or less, or 100 nm or less. In certain embodiments, the barrier comprises a thin oxide coating having 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 can consist of a thin oxide coating or can include a thin oxide coating and one or more additional material layers.

[0272] Nanostructure Layer Features and Embodiments

[0273] In some embodiments, the nanostructure layer is used to form a display device. As used herein, a display device refers to any system having an illuminated display. Such devices include, but are not limited to, devices including liquid crystal displays, emissive displays (e.g., organic light emitting diodes (OLEDs) or microLEDs), televisions, computers, mobile phones, smartphones, personal digital assistants (PDAs), gaming devices, electronic reading devices, digital cameras, and the like.

[0274] In some embodiments, the nanostructures are introduced into the display device by “on-chip” placement. As used herein, “on-chip” refers to placing the nanostructures into the light emitting diode cup. In some embodiments, the nanostructures are dissolved in a resin or liquid to fill the light emitting diode cup. In some embodiments, the nanostructures are introduced into the display device by “near-chip” placement. As used herein, “near-chip” refers to coating the top surface of the light emitting diode assembly with the nanostructures such that the emitted light passes through the nanostructure film.

[0275] Electroluminescent Devices

[0276] In some embodiments, the molded article is an electroluminescent device. In some embodiments, the nanostructured molded article is a liquid crystal display or a light emitting diode.

[0277] In some embodiments, the nanostructure composition is used to form an emissive layer of a lighting device. The lighting device can be used in a variety of applications such as flexible electronics, touchscreens, displays, televisions, mobile phones, and any other high-definition displays. In some embodiments, the lighting device is a light emitting diode or a liquid crystal display. In some embodiments, the lighting device is a quantum dot light emitting diode (QLED). Examples of QLEDs are disclosed in U.S. Patent Application No. 15 / 824701, which is incorporated herein by reference in its entirety.

[0278] In some embodiments, the present disclosure provides a light emitting diode comprising:

[0279] (a) a first conductive layer;

[0280] (b) a second conductive layer; and

[0281] (c) an emissive layer between the first conductive layer and the second conductive layer, wherein the emissive layer comprises at least one population of nanostructures, the nanostructures comprising (a) at least one population of nanostructures; and (b) at least one fluorine-containing ligand bound to the surface of the nanostructures; wherein the fluorine-containing ligand is selected from fluozincates, tetrafluoroborates, and hexafluorophosphates.

[0282] In some embodiments, the present disclosure provides a light-emitting diode, comprising:

[0283] (a) a first conductive layer;

[0284] (b) a second conductive layer; and

[0285] (c) an emission layer between the first conductive layer and the second conductive layer, wherein the emission layer comprises at least one population of nanostructures, the nanostructures comprising (a) at least one population of nanostructures; and (b) fluoride anions bound to the surface of the nanostructures.

[0286] In some embodiments, the emission layer is a nanostructured film.

[0287] In some embodiments, the light-emitting diode comprises a first conductive layer, a second conductive layer, and an emission layer, wherein the emission layer is disposed between the first conductive layer and the second conductive layer. In some embodiments, the emission layer is a thin film.

[0288] In some embodiments, the light-emitting diode comprises additional layers between the first conductive layer and the second conductive layer, such as a hole injection layer, a hole transport layer, and an electron transport layer. In some embodiments, the hole injection layer, the hole transport layer, and the electron transport layer are thin films. In some embodiments, the layers are stacked on a substrate.

[0289] When a voltage is applied to the first conductive layer and the second conductive layer, holes injected at the first conductive layer move to the emission layer via the hole injection layer and / or the hole transport layer, and electrons injected from the second conductive layer move to the emission layer via the electron transport layer. The holes and electrons recombine in the emission layer to generate excitons.

[0290] Substrate

[0291] The substrate can be any substrate commonly used in manufacturing light-emitting diodes. In some embodiments, the substrate is a transparent substrate, such as glass. In some embodiments, the substrate is a flexible material (such as polyimide), or a flexible and transparent material (such as polyethylene terephthalate). In some embodiments, the substrate has a thickness of about 0.1 mm to 2 mm. In some embodiments, the substrate is a glass substrate, a plastic substrate, a metal substrate, or a silicon substrate.

[0292] First conductive layer

[0293] In some embodiments, a first conductive layer is disposed on a substrate. In some embodiments, the first conductive layer is a stacked conductive layer. In some embodiments, the first conductive layer has a thickness between about 50 nm and about 250 nm. In some embodiments, the first conductive layer is deposited as a thin film using any known deposition technique (such as sputtering or electron beam evaporation). In some embodiments, the first conductive layer comprises indium tin oxide (ITO), indium zinc oxide, tin dioxide, zinc oxide, magnesium, aluminum, aluminum-lithium, calcium, magnesium-indium, magnesium-silver, silver, gold, or a mixture thereof. In some embodiments, the first conductive layer is an anode.

[0294] Second conductive layer

[0295] In some embodiments, the entire layer structure can be sandwiched between the first conductive layer and the second conductive layer. In some embodiments, the first conductive layer acts as the anode of the device, while the second conductive layer acts as the cathode of the device. In some embodiments, the second conductive layer is a metal, such as aluminum. In some embodiments, the second conductive layer has a thickness between about 100 nm and about 150 nm. In some embodiments, the second conductive layer represents a stacked conductive layer. For example, the second conductive layer can include a layer of silver sandwiched between two layers of ITO (ITO / Ag / ITO).

[0296] In some embodiments, the second conductive layer comprises indium tin oxide, an alloy of indium and zinc, titanium dioxide, tin oxide, zinc sulfide, silver, or a mixture thereof.

[0297] Semiconductor polymer layer

[0298] In some embodiments, the light-emitting diode further includes a semiconductor polymer layer. In some embodiments, the semiconductor polymer layer acts as a hole injection layer. In some embodiments, the semiconductor polymer layer is deposited on the first conductive layer. In some embodiments, the semiconductor polymer layer is deposited by vacuum deposition, spin coating, printing, casting, slot die deposition, or Langmuir-Blodgett (LB) deposition. In some embodiments, the semiconductor polymer layer has a thickness between about 20 nm and about 60 nm.

[0299] In some embodiments, the semiconductor polymer layer comprises copper phthalocyanine, 4,4',4”-tris[(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4'-tris(diphenylamino)triphenylamine (TDATA), 4,4',4'-tris[2-naphthyl(phenyl)amino]triphenylamine (2T-NATA), polyaniline / dodecylbenzenesulfonic acid, poly(3,4-ethylenedioxythiophene / polystyrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid, or polyaniline / poly(4-styrenesulfonate).

[0300] First transport layer

[0301] In some embodiments, the light-emitting diode further includes a transport layer to facilitate the transport of electrons and holes affected by the generated electric field between the first conductive layer and the second conductive layer. In some embodiments, the light-emitting diode further includes a first transport layer associated with the first conductive layer. In some embodiments, the first transport layer serves as a hole transport layer (and an electron and / or exciton blocking layer). In some embodiments, the first transport layer is deposited on the first conductive layer. In some embodiments, the first transport layer is deposited on a semiconductor polymer layer. In some embodiments, the first transport layer has a thickness between about 20 nm and about 50 nm. In some embodiments, the first transport layer is substantially transparent to visible light.

[0302] In some embodiments, the first transport layer comprises a material selected from amines, triarylamines, thiophenes, carbazoles, phthalocyanines, porphyrins, or mixtures thereof. In some embodiments, the first transport layer comprises N,N'-bis(naphthalen-1-yl)-N,N'-bis(4-vinylphenyl)-4,4'-diamine, poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)], or poly(9-vinylcarbazole).

[0303] Second transport layer

[0304] In some embodiments, the light-emitting diode further includes a second transport layer. In some embodiments, the second transport layer serves as an electron transport layer (and a hole and / or exciton blocking layer). In some embodiments, the second transport layer is in contact with the emission layer. In some embodiments, the second transport layer is disposed between the emission layer and the second conductive layer. In some embodiments, the second transport layer has a thickness between about 20 nm and about 50 nm. In some embodiments, the second transport layer is substantially transparent to visible light.

[0305] In some embodiments, the second transport layer comprises a material selected from imidazole, pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline (chinoline), quinoxaline (chinoxaline), anthracene, benzanthracene, pyrene, perylene, benzimidazole, triazine, ketone, phosphine oxide, phenazine, phenanthroline, triarylboraane, metal oxide, and combinations thereof. In some embodiments, the second transport layer comprises 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene (B3PyPB), bathocuproine, bathophenanthroline, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole, 3,5-bis(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, bis(8-hydroxy-2-methylquinolinato)-(4-phenylphenoxy)aluminum, 2,5-bis(1-naphthyl)-1,3,4-oxadiazole, 3,5-diphenyl-4-(1-naphthyl)-1H-1,2,4-triazole, 1,3,5-tris(m-pyridin-3-ylphenyl)benzene (TmPyPB), 2,2’,2”-(1,3,5-benzenetriyl)-tris(1-phenyl-1H-benzimidazole) (TPBi), tris(8-hydroxyquinoline)aluminum, TiO 2 、ZnO、SnO 2 、SiO 2 、ZrO 2 or ZnMgO. In some embodiments, the second transport layer comprises ZnMgO.

[0306] When the polarities of the first conductive layer and the second conductive layer are reversed, the roles of the first transport layer and the second transport layer are reversed.

[0307] Quantum dots on a glass liquid crystal display device

[0308] In some embodiments, a nanostructured film is introduced into quantum dots on a glass liquid crystal display device. The liquid crystal display device may include a nanostructured film formed directly on a light guide plate (LGP) without an intermediate substrate or barrier layer. In some embodiments, the nanostructured film may be a thin film. In some embodiments, the thickness of the nanostructured film may be 500 μm or less, 100 μm or less, or 50 μm or less. In some embodiments, the nanostructured film is a thin film with a thickness of about 15 μm or less.

[0309] The LGP may include an optical cavity having one or more sides (including at least one top side) that contains glass. The glass has excellent resistance to impurities including moisture and air. In addition, the glass can be formed into a thin substrate while maintaining structural rigidity. Thus, the LGP can be at least partially formed as a glass surface to provide a substrate with sufficient barrier and structural properties.

[0310] In some embodiments, the nanostructured film may be formed on the LGP. In some embodiments, the nanostructured film comprises a population of nanostructures embedded in a matrix material (such as a resin). The nanostructured film can be formed on the LGP by any method known in the art, such as wet coating, painting, spin coating, or screen printing. After deposition, the resin of the nanostructured film can be cured. In some embodiments, the resin of one or more nanostructured films can be partially cured, further processed, and then finally cured. The nanostructured film can be deposited as a single layer or separate layers, and the separate layers can have various properties. The width and height of the nanostructured film can be any desired size, depending on the size of the viewing panel of the display device. For example, in embodiments of small display devices such as watches and telephones, the nanostructured film can have a relatively small surface area, or for embodiments of large display devices such as TVs and computer monitors, the nanostructured film can have a large surface area.

[0311] In some embodiments, the optically transparent substrate is formed on the nanostructured film by any method known in the art (such as vacuum deposition, vapor deposition, etc.). The optically transparent substrate can be configured to provide an environmental seal to the underlying layer and / or structure of the nanostructured film. In some embodiments, a light blocking element can be included in the optically transparent substrate. In some embodiments, the light blocking element can be included in a second polarization filter, which can be located between the substrate and the nanostructured film. In some embodiments, the light blocking element can be a dichroic filter, which can reflect primary color light (such as blue light, UV light, or a combination of UV light and blue light) when emitting secondary light, for example. The light blocking element can include specific UV filtering components to remove any unconverted UV light from red and green subpixels, and / or remove UV light from blue subpixels.

[0312] Molded articles having improved properties

[0313] In some embodiments, a molded article prepared using nanostructures exhibits an EQE between about 1.5% and about 20%, about 1.5% and about 15%, about 1.5% and about 12%, about 1.5% and about 10%, about 1.5% and about 8%, about 1.5% and about 4%, about 1.5% and about 3%, about 3% and about 20%, about 3% and about 15%, about 3% and about 12%, about 3% and about 10%, about 3% and about 8%, about 8% and about 20%, about 8% and about 15%, about 8% and about 12%, about 8% and about 10%, about 10% and about 20%, about 10% and about 15%, about 10% and about 12%, about 12% and about 20%, about 12% and about 15%, or about 15% and about 20%. In some embodiments, a molded article prepared using nanostructures exhibits an EQE between about 1.5% and about 15%. In some embodiments, a molded article prepared using nanostructures exhibits an EQE of about 5%. In some embodiments, the nanostructures are quantum dots. In some embodiments, the molded article is a light-emitting diode.

[0314] The molded article exhibits improved stability as measured by the time to reach 80% of the initial brightness (500 nits) under operation, where the molded article is an electroluminescent device. In some embodiments, the electroluminescent device reaches 80% of the initial brightness after about 100 seconds to about 700 seconds, about 100 seconds to about 600 seconds, about 100 seconds to about 500 seconds, about 100 seconds to about 400 seconds, about 100 seconds to about 300 seconds, about 100 seconds to 200 seconds, 200 seconds to 700 seconds, 200 seconds to 600 seconds, 200 seconds to 500 seconds, 200 seconds to 400 seconds, 200 seconds to 300 seconds, 300 seconds to 700 seconds, about 300 seconds to about 600 seconds, about 300 seconds to about 500 seconds, about 300 seconds to about 400 seconds, about 400 seconds to about 700 seconds, about 400 seconds to about 600 seconds, about 400 seconds to about 500 seconds, about 500 seconds to about 700 seconds, about 500 seconds to 600 seconds, or about 600 seconds to 700 seconds. In some embodiments, the electroluminescent device reaches 80% of the initial brightness after about 600 seconds. In some embodiments, the electroluminescent device reaches 50% of the initial brightness after about 6 hours to about 11 hours, about 6 hours to about 10 hours, about 6 hours to about 9 hours, about 6 hours to about 8 hours, about 6 hours to about 7 hours, about 7 hours to about 11 hours, about 7 hours to about 10 hours, about 7 hours to about 9 hours, about 7 hours to about 8 hours, about 8 hours to about 11 hours, about 8 hours to about 10 hours, about 8 hours to about 9 hours, about 9 hours to about 11 hours, about 9 hours to about 10 hours, or about 10 hours and 11 hours. In some embodiments, the electroluminescent device reaches 50% of the initial brightness after about 10 hours.

[0315] The following examples are illustrative and non - limiting examples of the products and methods described herein. Appropriate modifications and adjustments of the various conditions, formulations, and other parameters commonly encountered in the art and obvious to those skilled in the art of the present invention in view of the present disclosure are within the spirit and scope of the present invention.

[0316] Embodiment

[0317] Example 1

[0318] Ligand Exchange and Properties of Nanostructures

[0319] Carboxylate ligands are exchanged for halozincate ligands (such as tetrachlorozincate, tetrafluorozincate, dichlorodifluorozincate), which are expected to undergo electrochemical oxidation at higher voltages than carboxylate ligands. In a subsequent step, the potassium counterions of the tetrafluorozincate - capped nanostructures are exchanged for tetraalkylammonium cations, which enables dissolution in non - polar solvents and makes the exchanged nanostructures compatible with the typical fabrication processes and structures of electroluminescent QD - LEDs. Figure 1 is a flow chart showing the ligand exchange process from carboxylate - capped nanostructures to tetrafluorozincate - capped nanostructures with tetraalkylammonium counterions.

[0320] Figure 2 is a schematic diagram showing the coordination of tetrafluorozincate to the nanostructure surface through monodentate and multidentate coordination modes, and illustrates the interaction between the nanostructure, fluoro - metalate ligands, and ammonium cations. The ammonium salt surfactant is not considered a ligand as it does not coordinate to the nanostructure surface. Surface passivation is provided by the inorganic halometalate ligands. The ammonium cations associate with the charged nanostructure surface through non - directional electrostatic interactions.

[0321] The exchange process applied to red InP nanostructures was followed by infrared spectroscopy ( Figure 3 ). Figure 3 shows the following infrared spectra: oleate - capped nanostructures (Sample 3 in Table 1); nanostructures capped with tetrachlorozincate and potassium counterions; and nanostructures capped with tetrachlorozincate and didodecyldimethylammonium counterions. The nanostructures capped with tetrachlorozincate and potassium counterions showed almost no alkyl signals (around 2900 cm -1 ), which demonstrates almost complete replacement of the initial oleate ligands. After cation exchange from potassium to didodecyldimethylammonium, signals corresponding to the ammonium ions and their alkyl chains were observed. The resulting material has a low organic content from the ammonium salt (e.g., a 15 wt% loss when heated to 600 °C in thermogravimetric analysis).

[0322] By 1The 1H NMR spectra provide further evidence for the removal of the native oleate ligands, which show only a small residual signal in the alkyl region at 5.4 - 5.8 ppm after exchange ( Figure 4 ). Figure 4 The following 1 1H NMR spectra are shown: nanostructures capped with oleate; and nanostructures capped with fluozincate ligands and didodecyldimethylammonium counterions (Sample 7 in Table 1). The 1H NMR spectra were acquired in a 20 mg / mL nanostructure solution in toluene-d8 using ferrocene as an internal standard. The inset shows an enlarged view of the alkyl region. For the native ligand sample, the broad and sharp signals in this region represent the double bonds in the bound and free oleate ligands, respectively. Finally, the presence of the inorganic ligand was confirmed by X-ray photoelectron spectroscopy, which showed a prominent F 1s signal for the 1 TBA 2 ZnF 4 -exchanged blue nanostructures ( Figure 5 ). Figure 5 The XPS spectra (F 1s region) of the TBA 2 ZnF 4 -exchanged blue ZnSe / ZnS nanostructures (Sample 8) compared to the non-exchanged nanostructures (Comparative Sample 2) are shown. The measured F / Zn ratio was 0.32.

[0323] Table 1 lists examples of nanostructure / ligand / surfactant / solvent combinations obtained by the above procedures and the corresponding solution photoluminescence properties. The emission peak wavelength shows only a slight red shift of up to 5 nm. The quantum yield shows a decrease of 2 - 27 percentage points due to ligand exchange. The fluozincate ligand shows the best quantum yield retention and was therefore studied in electroluminescent devices.

[0324] Table 1: Samples of different nanostructures, inorganic ligands, and surfactant / solvent combinations that produce colloidally stable solutions, and the corresponding photoluminescence peak wavelengths and quantum yields.

[0325]

[0326] *TBA: tetrabutylammonium; TMA: tetramethylammonium

[0327] Table 2 shows that such devices have a low external quantum efficiency, but the stability, measured by the time to reach 50% of the initial brightness (500 nits) under operation, is unexpectedly improved by an order of magnitude.

[0328] Table 2: Efficiency and lifetime characteristics of electroluminescent devices containing red nanostructures exchanged with different inorganic ligands.

[0329]

[0330]

[0331] Example 2

[0332] Ligand Exchange with TBAF and Properties of Nanostructures

[0333] The carboxylate ligand was exchanged for a fluorinated ligand by using tetrabutylammonium fluoride (TBAF). The presence of the highly soluble tetrabutylammonium cation as a counterion ensured that the exchanged quantum dots remained in solution. In contrast, the conventional zinc fluoride exchange described in Example 1 was accompanied by precipitation, and subsequent redispersion was facilitated by long-chain alkylammonium halides that only partially depolymerized the exchanged quantum dots. Figure 6 is a flow chart showing the ligand exchange process from carboxylate-capped nanostructures to fluoride-capped nanostructures.

[0334] The redispersion step using didodecyldimethylammonium chloride (DDAC) was still used for ligand exchange with TBAF because TBA alone + did not produce octane-soluble exchanged quantum dots. Octane is a preferred solvent for device fabrication because it does not damage the underlying layer during quantum dot deposition.

[0335] Figure 7 The thermogravimetric analysis shown indicates that most of the carboxylate ligands (zinc oleate) were removed by two ligand exchange processes using ZnF 2 or TBAF. The weight loss attributed to zinc oleate in the temperature range of 320 °C to 480 °C decreased from 11% (by weight) before ligand exchange to 5 to 6% (by weight) after ligand exchange. The weight loss of ZnF 2 at lower temperatures was related to the alkylammonium surfactant added for redispersion.

[0336] As Figure 8 shown, measured by stylus profilometry, the spin-coated film of TBAF-exchanged quantum dots showed fewer spikes due to aggregation and lower average roughness compared to the film prepared from quantum dots exchanged with ZnF 2 exchange.

[0337] And, compared to the devices prepared from quantum dots exchanged with ZnF 2 exchange, the electroluminescent devices prepared from TBAF-exchanged quantum dots showed higher brightness and higher efficiency, as Figure 9 shown. In addition, compared to ZnF 2Compared with the exchanged InP quantum dots, the device lifetime of the device prepared with the red InP quantum dots exchanged with TBAF increased by 4 times, as shown in Table 3. Generally speaking, when used in electroluminescent devices, the quantum dots exchanged with TBAF show better performance than the quantum dots exchanged with ZnF 2 exchanged quantum dots.

[0338] Table 3: Device efficiency and lifetime of electroluminescent devices

[0339]

[0340] The present invention has now been fully described. Those of ordinary skill in the art will understand that the present invention can be practiced within a wide and equivalent range of conditions, formulations, and other parameters without affecting the scope of the present invention or any of its embodiments. All patents, patent applications, and publications cited herein are hereby incorporated by reference in their entirety.

Claims

1. A nanostructured composition comprising: (a) at least one population of nanostructures; and (b) at least one fluorinated ligand bound to the surface of the nanostructures; wherein the nanostructured composition exhibits a photoluminescence quantum yield of 70% to 90%, wherein the nanostructures include a core and at least one shell, and at least one shell includes a first shell containing ZnSe and a second shell containing ZnS, wherein at least one fluorinated ligand includes an anion containing fluozincate and a cation containing a metal ion; or wherein at least one fluorinated ligand includes an anion containing fluozincate and a cation selected from tetraalkylammonium, and the tetraalkylammonium is selected from tetrabutylammonium, tetrapropylammonium, diisopropyldimethylammonium, tetraethylammonium, and tetramethylammonium.

2. The nanostructured composition according to claim 1, wherein the core comprises Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 、Ge 3 N 4 、Al 2 O 3 、Al 2 OC or a combination thereof.

3. The nanostructured composition according to claim 1 or 2, wherein the core comprises InP.

4. The nanostructured composition according to claim 1, wherein the nanostructures include two shells.

5. The nanostructured composition according to claim 1, wherein at least one shell contains CdS, CdSe, CdO, CdTe, ZnO, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si, or an alloy thereof.

6. The nanostructured composition according to claim 1, wherein the cation containing a metal ion includes potassium ions.

7. The nanostructured composition according to claim 1, wherein the molar ratio of fluorine atoms in the fluorinated ligand bound to the nanostructured composition to zinc atoms in the nanostructured composition is between 0.1 and 0.

5.

8. The nanostructured composition according to claim 1, wherein the molar ratio of fluorine atoms in the fluorinated ligand bound to the nanostructured composition to zinc atoms in the nanostructured composition is 0.

32.

9. The nanostructured composition according to claim 1, further comprising a solvent.

10. The nanostructured composition according to claim 9, wherein the solvent is selected from hexane, heptane, octane, toluene, chloroform, and N-methylformamide.

11. The nanostructured composition according to claim 9, wherein the solvent is a non-polar solvent.

12. The nanostructured composition according to claim 1, further comprising a surfactant.

13. The nanostructured composition according to claim 12, wherein the surfactant is selected from tetramethylammonium acetate, didodecyldimethylammonium bromide, dicetyldimethylammonium bromide, ditetradecyldimethylammonium bromide, didodecyldimethylammonium bromide, dicetyldimethylammonium bromide, didodecyldimethylammonium bromide, dioctyldimethylammonium bromide, bis(2-ethylhexyl)dimethylammonium bromide, octadecyltrimethylammonium bromide, oleyltrimethylammonium bromide, cetyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, decyltrimethylammonium bromide, octyltrimethylammonium bromide, phenethyltrimethylammonium bromide, benzyltrimethylammonium bromide, phenyltrimethylammonium bromide, benzylhexadecyldimethylammonium bromide, benzyltetradecyldimethylammonium bromide, benzyldodecyldimethylammonium bromide, benzyldecyldimethylammonium bromide, benzyloctyldimethylammonium bromide, benzyltributylammonium bromide, benzyltriethylammonium bromide, tetrabutylammonium bromide, tetrapropylammonium bromide, diisopropyldimethylammonium bromide, tetraethylammonium bromide, tetramethylammonium bromide, tetraphenylphosphonium bromide, dimethyldiphenylphosphonium bromide, methyltriphenoxyphosphonium bromide, hexadecyltributylphosphonium bromide, octyltributylphosphonium bromide, tetradecyltrihexylphosphonium bromide, tetrakis(hydroxymethyl)phosphonium bromide, tetraoctylphosphonium bromide, tetrabutylphosphonium bromide, tetramethylphosphonium bromide, dodecylammonium bromide, dioctadecyldimethylammonium chloride, dicetyldimethylammonium chloride, ditetradecyldimethylammonium chloride, didodecyldimethylammonium chloride, dicetyldimethylammonium chloride, didodecyldimethylammonium chloride, dioctyldimethylammonium chloride, bis(2-ethylhexyl)dimethylammonium chloride, octadecyltrimethylammonium chloride, oleyltrimethylammonium chloride, cetyltrimethylammonium chloride, tetradecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, decyltrimethylammonium chloride, octyltrimethylammonium chloride, phenethyltrimethylammonium chloride, benzyltrimethylammonium chloride, phenyltrimethylammonium chloride, benzylhexadecyldimethylammonium chloride, benzyltetradecyldimethylammonium chloride, benzyldodecyldimethylammonium chloride, benzyldecyldimethylammonium chloride, benzyloctyldimethylammonium chloride, benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium chloride, tetrapropylammonium chloride, diisopropyldimethylammonium chloride, tetraethylammonium chloride, tetramethylammonium chloride, tetraphenylphosphonium chloride, dimethyldiphenylphosphonium chloride, methyltriphenoxyphosphonium chloride, hexadecyltributylphosphonium chloride, octyltributylphosphonium chloride, tetradecyltrihexylphosphonium chloride, tetrakis(hydroxymethyl)phosphonium chloride, tetraoctylphosphonium chloride, tetrabutylphosphonium chloride, tetramethylphosphonium chloride, and dodecylammonium chloride.

14. The nanostructured composition according to claim 1, wherein the nanostructured composition exhibits a photoluminescence peak wavelength between 600 nm and 650 nm.

15. The nanostructured composition according to claim 1, wherein the nanostructured composition exhibits a photoluminescence peak wavelength between 510 nm and 560 nm.

16. The nanostructured composition according to claim 1, wherein the nanostructured composition exhibits a photoluminescence peak wavelength between 420 nm and 470 nm.

17. The nanostructured composition according to claim 1, wherein the fluorinated ligand is a salt of tetrafluorozincate or dichlorodifluorozincate.

18. The nanostructured composition according to claim 1, wherein the fluorinated ligand is tetrabutylammonium tetrafluorozincate or tetrabutylammonium dichlorodifluorozincate.

19. The nanostructured composition according to claim 1, wherein the nanostructure comprises a core containing InP, at least one shell containing ZnSe, at least one shell containing ZnS, and at least one fluorinated ligand containing a tetrafluorozincate or dichlorodifluorozincate.

20. The nanostructured composition according to claim 1, wherein the nanostructure is a quantum dot.

21. A method for preparing a nanostructured composition, the method comprising: (a) providing at least one population of nanostructures; (b) mixing at least one fluorinated ligand with the nanostructures of (a); to produce a nanostructured composition, wherein the nanostructured composition exhibits a photoluminescence quantum yield of 70% to 90%, wherein the nanostructure comprises a core and at least one shell, and at least one shell comprises a first shell containing ZnSe and a second shell containing ZnS; and wherein at least one fluorinated ligand comprises an anion containing fluorozincate and a cation containing a metal ion; or wherein at least one fluorinated ligand comprises an anion containing fluorozincate and a cation selected from tetraalkylammonium, and the tetraalkylammonium is selected from tetrabutylammonium, tetrapropylammonium, diisopropyldimethylammonium, tetraethylammonium, and tetramethylammonium.

22. The method according to claim 21, wherein the cation containing a metal ion comprises a potassium ion.

23. The method according to claim 21, wherein the core comprises Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 , Ge 3 N 4 , Al 2 O 3 , Al 2 OC or a combination thereof.

24. The method according to claim 21 or 23, wherein the core contains InP.

25. The method according to claim 21, wherein the nanostructure comprises two shells.

26. The method according to claim 21, wherein at least one shell contains CdS, CdSe, CdO, CdTe, ZnO, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si, or an alloy thereof.

27. The method according to claim 21, wherein the molar ratio of fluorine atoms in the fluorinated ligand bound to the nanostructured composition to zinc atoms in the nanostructured composition is between 0.1 and 0.

5.

28. The method according to claim 21, wherein the molar ratio of fluorine atoms in the fluorinated ligand bound to the nanostructured composition to zinc atoms in the nanostructured composition is 0.

32.

29. The method according to claim 21 or 22, further comprising dispersing the nanostructures of (b) in a nonpolar solvent.

30. The method according to claim 29, wherein the nonpolar solvent is selected from hexane, heptane, octane, toluene, and chloroform.

31. The method according to claim 21, wherein the mixing in (b) is carried out at a temperature between 10 °C and 100 °C.

32. The method according to claim 21, wherein the fluorinated ligand is a salt of tetrafluorozincate or dichlorodifluorozincate.

33. The method according to claim 21 or 22, wherein the fluorinated ligand is tetrabutylammonium tetrafluorozincate or tetrabutylammonium dichlorodifluorozincate.

34. A film comprising at least one population of nanostructures, wherein the nanostructures comprise: (a) at least one population of nanostructures, the nanostructures comprising a core and at least one shell; and (b) at least one fluorinated ligand bound to the surface of the nanostructures; wherein the nanostructures exhibit a photoluminescence quantum yield of 70% to 90%, wherein at least one shell comprises a first shell containing ZnSe and a second shell containing ZnS, and wherein at least one fluorinated ligand comprises an anion containing fluorozincate and a cation containing a metal ion, or wherein at least one fluorinated ligand comprises an anion containing fluorozincate and a cation selected from tetraalkylammonium, and the tetraalkylammonium is selected from tetrabutylammonium, tetrapropylammonium, diisopropyldimethylammonium, tetraethylammonium, and tetramethylammonium.

35. The film according to claim 34, further comprising at least one organic resin.

36. The film according to claim 34 or 35, comprising one to five populations of nanostructures.

37. The film according to claim 34, comprising one population of nanostructures.

38. The membrane according to claim 34, wherein the nanostructures of the at least one population comprise Si, Ge, Sn, Se, Te, B, C, P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeSe, GeTe, SnS, SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si 3 N 4 、Ge 3 N 4 、Al 2 O 3 、Al 2 OC or a combination thereof.

39. The film according to claim 34, wherein the nanostructures comprise a core of InP.

40. The film according to claim 34, wherein the nanostructures comprise at least two shells.

41. The film according to claim 34, wherein the nanostructures comprise two shells.

42. The film according to claim 34, wherein at least one shell contains CdS, CdSe, CdO, CdTe, ZnO, ZnTe, MgTe, GaAs, GaSb, GaN, HgO, HgS, HgSe, HgTe, InAs, InSb, InN, AlAs, AlN, AlSb, AlS, PbS, PbO, PbSe, PbTe, MgO, MgS, MgSe, MgTe, CuCl, Ge, Si, or an alloy thereof.

43. The film according to claim 34, wherein the cation containing a metal ion comprises a potassium ion.

44. The film according to claim 34, wherein the fluorinated ligand is a salt of tetrafluorozincate or dichlorodifluorozincate.

45. The film according to claim 34, wherein the fluorinated ligand is tetrabutylammonium tetrafluorozincate or tetrabutylammonium dichlorodifluorozincate.

46. The film according to claim 34, wherein the molar ratio of fluorine atoms in the fluorine-containing ligand combined with the nanostructured composition to zinc atoms in the nanostructured composition in the nanostructured film is between 0.1 and 0.

5.

47. The film according to claim 34, wherein the molar ratio of fluorine atoms in the fluorine-containing ligand combined with the nanostructured composition to zinc atoms in the nanostructured composition in the nanostructured film is 0.

32.

48. The film according to claim 34, wherein the nanostructure is a quantum dot.

49. The film according to claim 34, which comprises one to five organic resins.

50. The film according to claim 34, which comprises one organic resin.

51. The film according to claim 35, wherein the at least one organic resin is a thermosetting resin or a UV curable resin.

52. The film according to claim 35, wherein the at least one organic resin is a UV curable resin.

53. A molded article comprising the film according to any one of claims 34-52.

54. The molded article according to claim 53, wherein the molded article is an electroluminescent device.

55. The molded article according to claim 54, wherein the electroluminescent device is a light emitting diode or a liquid crystal display.

56. The molded article according to claim 54 or 55, wherein the maximum external quantum efficiency (EQE) of the electroluminescent device is between 1.5% and 15%.

57. The molded article according to claim 54, wherein the maximum external quantum efficiency (EQE) of the electroluminescent device is 5%.

58. The molded article according to claim 54, wherein the electroluminescent device reaches 80% of the initial brightness after 100 seconds to 700 seconds.

59. The molded article according to claim 54, wherein the electroluminescent device reaches 80% of the initial brightness after 600 seconds.

60. The molded article according to claim 54, wherein the electroluminescent device reaches 50% of the initial brightness after 6 hours to 11 hours.

61. The molded article according to claim 54, wherein the electroluminescent device reaches 50% of the initial brightness after 10 hours.

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