WO2018092039A1

WO2018092039A1 - Atomic layer deposition in combination with polymer coating

Info

Publication number: WO2018092039A1
Application number: PCT/IB2017/057139
Authority: WO
Inventors: Sang Hoon Kim; Eun-Uk KIM; Yaw-Ming Tsai
Original assignee: Sabic Global Technologies B.V.
Priority date: 2016-11-15
Filing date: 2017-11-15
Publication date: 2018-05-24

Abstract

Systems and methods for continuous, roll-to-roll formation of a quantum dot film are described. One system comprises serially aligned spatial atomic layer deposition and non- contact type solution coating processes.

Description

DESCRIPTION

ATOMIC LAYER DEPOSITION IN COMBINATION WITH POLYMER COATING

Technical Field

[0001] The disclosure generally relates to systems for the preparation of multi-layered quantum dot films.

Background

[0002] Quantum, dot enhancement film (QDEF) generally requires one or more barrier films or layers to ensure reliability and lifetime of the QDEF. "Enhancement" may refer to the improvement in optical qualities, such as color quality and depth, observed by incorporating the QDEF in certain lighting appliances and applications. Conventionally, a quantum dot layer is formed on a barrier film substrate. Another barrier film may be added to the surface of the quantum dot layer. Often, the barrier layer may be laminated onto the surface of the quantum dot layer of the QDEF. The layering processes for the application of the quantum dot layer and the barrier layer are typically distinct. The barrier film fabrication process is not connected to the quantum dot layer fabrication process as the barrier film is often applied in a separate stage or according to a different method. Such a separation between the processes for layer application may increase the cost of production associated with manufacturing QDEF. Other processes, such as wet barrier or other processes by which the barrier film is applied via a solution coating process, may improve upon production costs. However, solution-coating processes providing a wet barrier may exhibit less barrier performance: exemplary wet barrier processes may provide a water vapor transmission rate of about 9.5 x 10^"2 grams per square meter per day.

[0003] These and other shortcomings are addressed by aspects of the present disclosure. Summary

[0004] In accordance with one aspect of the disclosure, a quantum dot film may be formed by a process comprising: continuously feeding a substrate into a vacuum deposition chamber, the deposition chamber comprising at least a first precursor zone, a purge zone, and a second precursor zone; advancing the substrate through at least the first precursor zone, the purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate to provide a layered substrate; conveying the layered substrate through a pressure gradient system, wherein the pressure gradient system adjusts pressure at the substrate so that the pressure at the substrate is greater than a pressure within the vacuum deposition chamber; applying a quantum dot resin coating to the layered substrate via a non-contact type coating process to provide a quantum dot resin coated substrate; and curing the quantum dot resin coated substrate in a curing zone to provide the quantum dot film.

Brief Description of the Drawings

[0005] The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become apparent and be better understood by reference to the following description of one aspect of the disclosure in conjunction with the accompanying drawings, wherein:

[0006] FIG. 1 shows a schematic diagram of exemplary layered films according to aspects of the present disclosure.

[0007] FIG. 2 shows a schematic diagram of monolayer growth in a conventional atomic layer deposition process.

[0008] FIG. 3 shows a schematic diagram of a conventional spatial atomic layer deposition system.

[0009] FIG. 4 shows a schematic diagram of a sequentially coupled spatial atomic layer deposition process and non-contact type solution coating process for a layered substrate according to aspects of the present disclosure.

[0010] FIG. 5 shows a schematic diagram of a sequentially integrated spatial atomic layer deposition process, a non-contact type solution coating process, and a spatial atomic layer deposition process.

[0011] FIG. 6 presents a schematic diagram for an apparatus used to determine the water vapor transmission rate according to a calcium test.

[0012] FIG. 7 presents normalized conductance 1/R as a function of time (hours) for barrier films.

Detailed Description

[0013] The present disclosure provides an efficient means of preparing a quantum dot (QD) film (or a QDEF) with one or more barrier layers to protect the QD layer from oxygen and moisture. Spatial atomic layer deposition and solution coating processes have been combined in a continuous, roll-to-roll process according to the systems and methods disclosed herein to provide a quantum dot film that exhibits a water vapor transmission rate from about 10^"1 grams per square meter per day (g/m²/day) to about 10^"6 g/m²/day. The process integration may allow for less manipulation of the applicable substrate roll, such as winding and unwinding, between the barrier layer deposition process and the quantum dot coating process. Removal of the substrate handling procedures can limit potential damage to the sensitive barrier layer and prevent deterioration of quality of the ultimate QD film.

[0014] Quantum dots are known to degrade upon exposure to moisture or air. In the presence of light, oxygen and water molecules may cause photo-oxidation and photo- corrosion at the surface of the quantum dots. Defects continue to form on the surface of the quantum dots after the air or moisture exposure. Eventually, these defects may diminish the light emitting quality of the quantum dots. To prevent this degradation, it is necessary to exclude oxygen and moisture to the extent possible. A quantum dot film thus may comprise a quantum dot layer situated between barrier layers to protect the quantum dot from degradation factors such as oxygen and moisture.

[0015] In conventional quantum dot films, a quantum dot layer is composed between a first barrier layer and a second barrier layer to protect the quantum dot from degradation factors such as oxygen and moisture. Typically, the barrier film fabrication process is separate from that for depositing the quantum dot layer. Barrier layers are generally formed using techniques employed in the film metallizing art such as sputtering, evaporation, chemical vapor deposition, plasma deposition, atomic layer deposition, plating and the like. A second barrier film is often laminated onto the quantum dot layer and the thickness of each barrier layer is sufficient to eliminate wrinkling in roll-to-roll or laminate manufacturing processes. However, these isolated processes of first forming the barrier layer on the substrate and then separately forming the quantum dot layer tend to increase manufacturing costs. Separate processes also require more manipulation of the substrate via unwinding and rewinding between processes.

[0016] In various aspects, the methods and systems described herein provide a continuous, roll-to-roll process for the formation of a quantum dot film. According to the present disclosure, one or more barrier layers may be delivered to a suitable flexible substrate via spatial atomic layer deposition to provide a layered substrate. The layered substrate may be subjected to a pressure gradient before a non-contact coating process to deposit a quantum dot coating or layer. A change in the substrate feed, such as a roll on an unwinder, is not required as the processes are serially connected or aligned. The serially connected processes may thus be more efficient as substrate rolls need not be changed to transition between barrier layer deposition and quantum dot layer deposition and so forth. The serially connected processes may further reduce the manipulation of the substrate during layer deposition thus limiting damage to the substrate during processing. Film quality may be maintained and the processes more reproducible. Higher speed processing is also enabled by the serially connected processes. Further, the inorganic barrier layers delivered via spatial atomic layer deposition exhibit a barrier performance of between about 10^"1 g/m²/day and 10^" ⁶ g/m²/day and a high moisture barrier property.

[0017] A quantum dot film prepared according to the methods herein may comprise a number of variations for the order of its constituent layers. FIG. 1 provides a non-limiting selection of configurations for the layers of the QD film. In some aspects, because quantum dots are highly susceptible to degradation from both moisture and oxygen, the quantum dot layer may be disposed between barrier layers. FIGs. la - Id. As a further example, a barrier substrate may be coupled to a diffusing material, or a "diffuser," (FIG. la, b, and d). Often, the agglomeration of particles within the layers of a QD film may affect the emission of light therefrom and/or the transmission of light therethrough. The diffuser may be used to augment luminescence and uniformity of light entering the QD film when the film is used in certain lighting applications.

[0018] In some aspects, a QD film may further comprise a brightness enhancement film (BEF). FIG. lb. As the name implies, the brightness enhancement film may be included to increase brightness at the film surface, which is particularly useful in backlights in liquid crystal displays. The BEF may improve brightness via the film's geometrically random, prismatic structure which can recycle diffuse light into a backlight and direct light through the film. An exemplary BEF may comprise materials including polyethylene, polyethylene terephthalate, or polycarbonate, among others.

[0019] As provided herein, quantum dot films typically comprise a quantum dot layer and one or more barrier layers. The harrier layer may prevent the deterioration of the quantum dots from environmental conditions including moisture and oxygen. Barrier layers may be formed from any useful material that limits permeation of water and oxygen to the sensitive quantum dot resin.

[0020] The barrier layer may comprise organic or inorganic material. Suitable materials for a barrier layer may include polymers (i.e., polyethylene terephthalate, or PET); oxides such as silicon oxides, metal oxides, metal nitrides, metal carbides, metal oxynitrides and suitable combinations thereof. In certain aspects, the barrier layer comprises inorganic materials. As a specific example, the barrier layer may comprise aluminum oxide, titanium oxide, a mixed oxide, or a combination thereof.

[0021] The quantum dot layer may include one or more populations of quantum dots. In an aspect, quantum dots may be dispersed throughout a desired polymeric matrix or resin.

These quantum dots may comprise semiconducting nanocrystals usually ranging from 2 nanometers (nm) to 10 nm (approximately 10-50 atoms) in diameter. The quantum dots may emit or glow a particular color upon illumination with light, with the color emitted depending on the size of the nanoparticle. For example, when quantum dots are illuminated by ultraviolet (UV) light, some of the electrons receive enough energy to break free from the atoms. This allows the electrons to move around the nanoparticle, creating a conductance band in which electrons are free to move through a material and conduct electricity. As the electrons drop back into the outer orbit around the atom (the valence band), they emit light. The color of that light depends on the energy difference between the conductance band and the valence band. Respective portions of red, green, and blue light emitted by quantum dots may thus be tuned, or controlled, to achieve a desired white point for white light emitted by a display device, for example, featuring a quantum dot film article.

[0022] Quantum dots ass provided herein may be produced from any suitable material, such as an inorganic material, or more suitably any inorganic conductive or semi -conductive material. Useful semiconductor materials may include any type of semiconductor, including group II- VI, group III-V, group IV-VI and group IV semiconductors. Exemplary semiconductor materials include, but are not limited to, silicon Si, germanium Ge, tin Sn, selenium Se, tellurium Te, B boron, carbon C (including diamond), phosphorus P, boron nitride BN, boron phosphide BP, boron arsenide BAs, aluminum nitride A1N, aluminum phosphide A1P, aluminum arsenide AlAs, aluminum antimonide AlSb, gallium nitride GaN, gallium phosphide GaP, gallium arsenide GaAs, gallium antimonide GaSb, indium nitride InN, indium phosphide InP, indium arsenide InAs, indium antimonide InSb, zinc oxide ZnO, zinc sulfide ZnS, zinc selenide ZnSe, zinc telluride ZnTe, cadmium sulfide CdS, cadmium selenide CdSe, cadmium selenide and zinc CdSe Zn, cadmium telluride CdTe, mercury sulfide HgS, mercury selenide HgSe, mercuring telluride HgTe, beryllium sulfide BeS, beryllium selenide BeSe, beryllium telluride BeTe, magnesium sulfide MgS, magnesium selenide MgSe, germanium disulfide GeS, germanium selenide GeSe, germanium telluride GeTe, tin(II) sulfide SnS, tin(II) selenide SnSe, tin telluride SnTe, lead(II) oxide PbO, lead(II) sulfide PbS, lead selenide PbSe, lead telluride PbTe, copper(I) fluoride CuF, copper chloride CuCl, copper(I) bromide CuBr, copper(I) iodide Cul, silicon nitride S13N4, germanium nitride Ge3N4, aluminum oxide AI2O3, (aluminum Al, gallium Ga, indium In)2 (sulfur S, selenium Se, tellurium Te)3, aluminum carbonate AI2CO3, and appropriate combinations of two or more such semiconductors.

[0023] Quantum dots for use in quantum dot film articles described herein may include core/shell luminescent nanocrystals including CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS. More specifically, the quantum dots may comprise GaAs, CdSe, InP, or a combination thereof. In a specific example, the quantum dot material may comprise a combination of quantum dot materials, such as a CdSe/CdS/ZnS combination.

[0024] In various aspects, the quantum dot layer generally comprises quantum dot material dispersed throughout a matrix, typically a polymer resin matrix. Quantum dots are often dispersed throughout hydrophobic resins, such as acrylates, compared to more hydrophilic resins, such as epoxies. Thus, polymer films made of QDs dispersed in hydrophobic acrylates tend to have higher initial quantum yields (QYs) than QD films using hydrophilic resins such as epoxy resins. However, acrylates tend to be permeable to oxygen, while epoxy resin polymers and similar hydrophilic polymers tend to be better at excluding oxygen. For wet barrier processes, hydrophilic polymers may be more appropriate.

[0025] Exemplary polymer resin matrix materials may include, but are not limited to, poly(methyl(meth)acrylate), poly(ethyl(meth)acrylate), poly(n-propyl(meth)acrylate), poly(butyl(meth)acrylate), poly(n-pentyl(meth)acrylate), poly(n-hexyl(meth)acrylate), poly(cyclohexyl(meth)acrylate), poly(2 -ethyl hexyl(meth)acrylate),

poly(octyl(meth)acrylate), poly(isooctyl(meth)acrylate), poly(n-decyl(meth)acrylate), poly(isodecyl(meth)acrylate), poly(lauryl(meth)acrylate), poly(hexadecyl(meth)acrylate), poly(octadecyl(meth)acrylate), poly(isobornyl(meth)acrylate), poly(isobutylene), polystyrene, poly(divinyl benzene), polyvinyl acetate, polyisoprene, polycarbonate, polyacrylonitrile, hydrophobic cellulose based polymers like ethyl cellulose, silicone resins, poly(dimethyl siloxane), poly(vinyl ethers), polyesters or any hydrophobic host material such as wax, paraffin, vegetable oil, fatty acids and fatty acid esters. In some aspects, the polymer resin matrix may comprise a methacryl-based polymer, a polyvinyl alcohol, poly(ethylene oxide), polybutyl acrylate, poly(methylmethacrylate), polylactic acid (PLA), poly(N- methylolacrylamide, and polystyrene. In specific aspects, the polymer resin matrix may comprise bisphenol A diglycidyl ether or 1,4-butanediol diglycidyl ether.

[0026] Quantum dots and quantum dot material (resin matrix) are commercially available from Nanosys Inc., Palo Alto, CA. The quantum dot material may have any useful amount of quantum dots. In many aspects the quantum dot layer can have from 0.1 weight percent (wt. %) to 1 wt. % quantum dots.

[0027] As provided herein, the quantum dot film may comprise a substrate upon which the barrier and quantum dot layers are disposed. Reference to depositing on a substrate can mean both a bare substrate and a substrate with one or more films or features deposited or formed thereon. The substrate may be sufficiently flexible to allow the substrate to be conveyed through the integrated processes of spatial atomic layer deposition for the addition of barrier layers, of solution coating for the addition of quantum dot layers, and of an appropriate curing process such as thermal or ultraviolet curing. The substrate may be wound on a roll for a continuous feed to serially aligned processes. In a specific example, the substrate may be supplied from an unwinder or re winder roll.

[0028] A number of polymers may be useful as the sufficiently flexible substrate.

Sufficiently flexible may refer to the ability of the substrate to be about an unwinder or rewinder roll. Exemplary substrates may include polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI) or colorless PI. In a specific example, the substrate is PET as PET materials are known for favorable optical and mechanical properties as well as low cost and ease of processing.

[0029] Spatial atomic layer deposition (s-ALD) may be used to deposit a barrier layer to the desired substrate according to several aspects of the present disclosure. In a conventional atomic layer deposition (ALD) process, a substrate for coating is pretreated to become chemically reactive and then placed in a vacuum chamber and heated. Upon heating to a desired temperature, the chamber is filled with a certain amount of coating gas. At elevated temperatures, the molecules of the gas react with the surface of the substrate causing a single molecular layer to be attached to the surface of the substrate. In a subsequent process step, the gas in the chamber is changed and the coated layer is chemically activated. The gas in the chamber is then exchanged again to deposit another molecule layer. By repeating the activation and coating process steps an ALD coating is created. The molecular size of the precursor gas may determine the film thickness per cycle. Film density may depend on the molecular volume of the precursor. That is, a molecule with steric hindrance will probably prevent the formation of a monolayer while small molecules without steric hindrance may allow the formation of a full monolayer. The density of the reactive sites on the substrate may also contribute to the nature of the film obtained. One cycle can take from half a second to a few seconds depending on the reactivity between the gas precursors and the solid substrate. For the deposition of a single layer, a typical ALD growth cycle may include four stages: 1) exposure of the first precursor, 2) purge of the reaction chamber, 3) exposure of the second precursor, and 4) a further purge of the reaction chamber. FIG. 2 depicts an exemplary ALD growth process for aluminum oxide layer formation requiring exposure to two precursor gases: trimethyl aluminum (per stage 1) and water H2O (per stage 3). In a spatial ALD (s- ALD) process, rather than exposing the substrate at different times to a precursor gas, the substrate instead traverses different precursor zones to effect the growth layers.

[0030] Generally, an s-ALD process for barrier layer deposition may involve guiding a flexible substrate back and forth among multiple chambers, or precursor zones, equipped with a reactive precursor gas so that the substrate travels through each of the precursor zones multiple times. The flexible substrate may be conveyed in a serpentine web path as the flexible substrate traverses each precursor zone in a deposition chamber. The barrier layer may be deposited on a surface of the substrate as the substrate passes through each zone alternately.

[0031] FIG. 3 provides a schematic for a conventional spatial atomic layer deposition process including a deposition chamber 300. A substrate 302 may be fed to the deposition chamber 300 from an unwinder 304. The deposition chamber may include distinct zones, a first precursor zone 306, an inert gas zone 308, and a second precursor zone 310. The inert gas zone 308 may separate the first and second precursor zones 306, 310. The distinct zones may be situated across the deposition chamber 300. The first and second precursor zones 306, 310 may include conveying guide rolls 312 to direct the substrate 302 along a serpentine path within the deposition chamber 300 such that the substrate 302 enters the zones 306, 308, 310 alternately. The substrate 302 may travel laterally through the zones 306, 308, 310 allowing for the deposition of a barrier layer at the substrate 302. The resulting layered substrate 314 may be wound on a rewinder 316 as the rolled product.

[0032] Precursor zones in the atomic layer deposition chamber may be delineated in a number of ways. The s-ALD deposition chamber may comprise a number of discrete chambers corresponding to the individual precursor zones. In further examples, the s-ALD deposition chamber may include discrete precursor zones delineated by a divider. The divider may be configured to separate the discrete precursor zones. For example, the divider may comprise a gas curtain or a chamber wall disposed within the deposition chamber. Each precursor zone may be supplied with a precursor gas. The precursor gas may comprise a reactive gas that interacts with the surface of the substrate to grow a layer of film thereupon. The precursor gas may also comprise an inert precursor gas in the inert gas zone so as to "purge" the surface of the substrate between reactive precursor gas zones. [0033] Upon heating to a desired temperature, the chamber is filled with a certain amount of coating gas. The surface of the flexible substrate may be activated in a first precursor zone. The molecules of the precursor gas of the first precursor zone may react with the surface of the substrate causing a single molecular layer to be attached to the surface of the substrate. The substrate may then proceed to the purge gas zone and then enter a second precursor gas zone where molecules of a second precursor gas react with the substrate surface to form another layer. The process repeats as the flexible substrate continues its serpentine path and the s-ALD layers are deposited.

[0034] In an aspect, the flexible substrate may traverse the first precursor zone where the precursor gas may react with the substrate surface. In one example, the first precursor zone may comprise a metal-containing compound in gas form (for example, a metallic compound such as titanium tetrachloride (TiCk)) or trimethylaluminum (TMA) which may react with the surface of the flexible substrate to deposit a metal-containing compound thereupon. The substrate may then proceed to the inert precursor zone to purge the substrate surface. The flexible substrate may proceed to the second precursor zone which reacts with the previous compound deposited at the substrate surface to form a monolayer. As an example, the second precursor zone may comprise a hydrolyzing compound, such as water. In some examples, the first precursor zone may comprise water while the second precursor zone may comprise titanium tetrachloride (TiCk) and trimethylaluminum (TMA). After monolayer formation, the flexible substrate may continue its serpentine path, again traversing the inert precursor zone for purging and the cycle of layer deposition begins again. This cycle may repeat along the deposition chamber to establish the desired film or layer. The deposition of layers at the substrate surface may proceed as in the conventional ALD process described herein, for example, as in FIG. 2.

[0035] Exemplary precursor gases of the precursor zones may include TiCk and TMA. An exemplary deposited film layer based upon a first precursor gas of TMA and second precursor gas of H2O may comprise aluminum oxide, e.g., AI2O3. In a further example, a first precursor gas of TiCk and a second precursor gas of H2O may provide a titanium oxide (T1O2) layer.

[0036] The s-ALD process may be carried out at low temperature. Generally, the s-ALD process may proceed at a temperature of from about 20° C to about 300° C, more specifically from about 100° C to 250° C. In addition, the deposition reactions may take place on the substrate surface and a single atomic layer of material may be applied at a time. The layer of material applied may be less than 100 nm thick, more specifically less than 50 nm in thickness. Because the film may be grown one monolayer at a time, the film tends to be conformal and have a uniform thickness.

[0037] The s-ALD process may be performed in vacuum deposition chamber. The use of a vacuum deposition chamber allows for the process of s-ALD to be performed at low pressure. For example, a low vacuum pressure for the s-ALD deposition chamber may range from about 25 Torr to about 760 Torr, more specifically, about 100 Torr to about 760 Torr.

[0038] According to the systems and methods provided herein, a barrier layer may be formed by a spatial atomic layer deposition process before the addition of a quantum layer in a serially connected solution coating process. One or more barrier layers of the present disclosure may be delivered to a substrate by a process of spatial atomic layer deposition. Spatial atomic layer deposition may be used to deposit a barrier layer on a substrate such that the barrier layer has a thickness of between about 5 nm and 50 nm.

[0039] The serially aligned s-ALD and solution coating processes provided herein may be roll-to-roll. In a roll-to-roll process, a flexible substrate may be continuously transferred between two or more moving rolls of material. The roll-to-roll process allows for the production of rolls of finished material in an efficient and cost effective manner at high throughput, or production rates, and mass quantities.

[0040] In various aspects of the present disclosure, a pressure gradient may be established between the process of spatial atomic layer deposition of the barrier layer under vacuum and the process of non-contact solution coating of the quantum dot resin coating. Thus, the layered substrate may be conveyed through a pressure gradient system subsequent the s-ALD process depositing the barrier layer. The pressure gradient system may adjust pressure at the substrate so that the pressure at the substrate is greater than a pressure within the vacuum deposition chamber. That is, the barrier layer may be deposited on the substrate under vacuum pressure and the substrate may be subjected to increasing pressure before application of the quantum dot resin coating at atmospheric pressure. For example, the layered substrate may traverse the pressure gradient or pressure gradient system, i.e., a series of zones having increasing pressure until pressure at the substrate is atmospheric pressure. Here, the pressure gradient may comprise a series of pressure chambers wherein each successive chamber exhibits a greater pressure than its preceding pressure chamber. Conversely, the substrate may traverse a single zone, or a single pressure chamber, where the pressure is gradually increased to atmospheric pressure over discrete intervals of time depending upon the performance of a vacuum pump configured to the deposition system. In one example, the pressure gradient may comprise a pressure chamber allowing passage therethrough within which pressure is adjusted over time. As a further example, the pressure gradient may comprise a series of pressure chambers oriented adjacent the s-ALD deposition chamber allowing passage therethrough the pressure chambers. A pressure of each pressure chamber is greater than the pressure of a preceding chamber beginning with the chamber of the series of pressure chambers closest to the s-ALD deposition chamber.

[0041] In a specific example, the substrate having the deposited barrier layer may exit the vacuum deposition chamber and enter a pressure gradient at a high vacuum at about 10 Torr. The substrate may then be conveyed to a medium vacuum area of about 100 Torr. The substrate may then be conveyed to a low vacuum area of about 760 Torr before entering an area of atmospheric pressure for the non-contact type, solution coating process to deposit the quantum dot layer.

[0042] After traversing a pressure gradient, the substrate having the deposited barrier layer may be subjected to a non-contact type coating process for delivery of the quantum dot resin coating. A non-contact type solution coating process may refer to a process of delivering a coating to a substrate wherein the substrate is not in direct contact with the instrumentation configured to apply the coating. The non-contact coating process may limit contact with the barrier layer, and thereby prevent damage thereto. Exemplary non-contact type coating processes may include, but are not limited to, capillary coating, slot die coating, plasma polymerization coating, sputtering coating, evaporation coating, or inkjet coating. In a specific example, the non-contact type solution coating process is a slot die coating process.

[0043] In some aspects, the quantum dot resin coating may be deposited at the barrier layer of the substrate via a slot die process as a non-contact type coating process. As an example, the quantum dot resin coating may be discharged by gravity or via pressure through a slot (or slit) of a slot die onto the deposited barrier layer of the moving substrate. Alternatively, the slot die may be moved over the barrier layer with a set speed. Accurate control of the uniformity of the quantum dot resin coating may depend upon complex interactions between the quantum dot resin formulation, the slot positioning relative to the substrate, and the die slot geometry. Die slot geometry may include considerations such as the size of the gap through which the resin is deposited; the lip thickness of the die; or the size of the coating gap (the distance between the lip thickness and the surface to be coated). The speed of the substrate relative to the slot die allows for the quantum dot layer coating to be considerably thinner than the gap (or width) or of the slot. In some examples, the slot gap may be between 2 and 10 times the thickness of the film. In further examples, an adjustable slot gap may be advantageously used to optimize coating conditions to specific substrates and specific quantum dot resin coating formulations.

[0044] After the quantum dot layer has been deposited, the film may be subjected to one or more curing processes. The layer may be cured by contacting the layer with water. For example, the layer can be contacted with water vapor, liquid water, water adsorbed or absorbed by the substrate the layer, or a plasma containing water vapor. Curing may also be performed with heat. Thermal curing may be provided using any suitable source, such as, for example, an infrared heater or a catalytic combustion burner. Curing may also be achieved by ultraviolet (UV) or vacuum UV light exposure. A photo-sintering process of pulsed irradiation may be useful in curing polymers with metals embedded therein.

[0045] The curing process may depend upon the type of polymer resin forming the matrix of the quantum dot layer. Curing zones may be adjusted to accommodate longer processing times. In certain aspects, the curing process may comprise a thermal drying process. As an example, thermal curing may be achieved at temperatures between about 60 °C to about 350 °C, more specifically from 80 °C to 120 °C, depending upon the film material. Curing may be carried out between 20 seconds and 1 hour. In a specific example, curing may be carried out between 20 seconds and 2 minutes. In further aspects, curing may comprise an ultraviolet curing process.

[0046] The cured film comprising the layered substrate may be wound on an unwinder to provide the rolled film as a result of the roll-to-roll process.

[0047] As shown in FIG. 4, the roll to roll system of the present disclosure may include a substrate 401 fed from an unwinder 403 through an inlet 405 of a deposition chamber 407 to a primary guide roll 409 disposed therein. The deposition chamber 407 may comprise distinct zones including a first precursor zone 411, an inert gas zone 413, and a second precursor zone 415. The first and second precursor zones 411, 415 may include a plurality of conveying rods 417 to advance the substrate 401 along a serpentine path within the deposition chamber 407 such that the substrate 401 enters the first and second precursor zones 411, 415 alternately. An exit guide roll 419 may be disposed within the inert gas zone 413 of the deposition chamber 407 to direct the substrate 401 from the deposition chamber 407 to a pressure gradient system 421 disposed adjacent the deposition chamber 407. A receiving guide roll 423 may be disposed downstream from the pressure gradient 421 to receive the substrate 401 and guide the substrate 401 to a coating guide roll 425. The coating guide roll 425 may position the substrate 401 so as to receive a quantum dot resin coating from a slot die apparatus 427 situated adjacent to, but not in contact with, neither the substrate 401 nor the coating guide roll 425. Adjacent the coating guide roll 425 may be disposed one or more curing zones 429, 431, each of which succeeded by one or more curing guide rolls 433, 435. A rewinder 437 may be disposed adjacent the curing zones 429, 431 to coil the substrate 401 into a product roll of quantum dot film.

[0048] In a specific example, the substrate 401 may be fed from the unwinder 403 through the inlet 405 of the deposition chamber 407 to the primary guide roll 409 disposed within the deposition chamber 407. Reactive precursor gases may be continuously supplied to each respective precursor zone 411, 415 while an inert gas is supplied to the inert gas zone 413. The substrate 401 may be conveyed via a serpentine pathway alternately through the zones 411, 413, 415 of the deposition chamber 407 via the conveying rods 417 disposed along the first and second precursor zones 411, 415. As the substrate 401 traverses the zones 411, 413, 415 of the deposition chamber 407, a barrier layer is deposited at a surface of the substrate 401. The barrier layer grows as the substrate 401 is directed by the conveying rods 417 through the deposition chamber 407. At the exit guide roll 419, the layered substrate 401 may be conveyed to a pressure gradient system 421. In the pressure gradient 421, pressure may be gradually increased from about 25 Torr pressure to atmospheric pressure. From the pressure gradient 421, the layered substrate 420 may be conveyed via a receiving guide roll 423 to the coating guide roll 425. The coating guide roll 425 orients the layered substrate 420 to receive a deposit of a quantum dot resin coating from the slot die apparatus 427. As the layered substrate 401 is conveyed by the coating guide roll 425, an amount of quantum dot resin coating is deposited at the substrate 401 thereby creating a thin film or coating of the quantum dot resin coating along the moving substrate 401. The coated substrate 401 comprising the quantum dot resin coating is then conveyed to one or more curing zones 429, 431. In an example, the substrate 401 may be conveyed to a first thermal curing (or drying) zone 429 to set the solution coated quantum dot resin layer. A UV curing process may be applied in the UV curing zone 431 to further set the layers of the substrate 401, now a cured quantum dot film. The cured quantum dot film formed of the substrate 401 may be wound on a rewinder to provide a roll of the quantum dot film.

[0049] In some aspects, the system described herein may comprise serially aligned processes of a first s-ALD, a non-contact type solution coating process, and a second s-ALD process. The series of processes may provide a quantum dot film wherein a barrier layer is deposited on a substrate via s-ALD, a quantum dot resin layer is applied via a non-contact type solution coating process, the layers are cured, and a second barrier layers is deposited. The formed film may comprise a substrate, a barrier layer, a quantum dot layer, and a second barrier layer. A system for the preparation of the film may be exemplified in FIG. 5.

[0050] Referring to FIG. 5, the substrate 501 may be fed from an unwinder 503 to a deposition chamber 507. The substrate 501 may enter the deposition chamber 507 via an inlet 505. Reactive precursor gases may be continuously supplied to respective first and second precursor zones 511, 515 while an inert gas is supplied to an inert gas zone 513. The substrate 501 may be conveyed via a serpentine pathway alternately through the zones 511, 513, 515 of the deposition chamber 507 via conveying rods 517 disposed along the first and second precursor gas zones 511, 515. As the substrate 501 traverses the zones 511, 513, and 515 of the deposition chamber 507, a barrier layer forms at a surface of the substrate 501. As the substrate 501 is directed by the conveying rods 517, the barrier layer grows. At an exit guide roll 519, the substrate 501 now including a barrier layer may be conveyed to a pressure gradient system 521. In the pressure gradient 521, pressure at the substrate 501 may be gradually increased from about 25 Torr to atmospheric pressure. From the pressure gradient 521, the barrier-layered substrate 501 may be conveyed via a receiving guide roll 523 to a coating guide roll 525. The coating guide roll 525 orients the layered substrate 501 to receive a deposit of a quantum dot resin coating from a slot die apparatus 527. As the barrier-layered substrate 501 is conveyed by the coating guide roll 525, an amount of quantum dot resin coating is deposited at the substrate 401 thereby creating a thin film or coating of the quantum dot resin coating along the moving substrate 501. Subsequent the slot die process, the substrate may be conveyed to a curing zone 529.

[0051] The cured substrate 501 (now a cured film 501 comprising the substrate, barrier layer, and quantum dot layer) may then proceed via one or more second conveying rolls 539, 541 into a second inlet 543 of a second deposition chamber 545. The second deposition chamber 545 may comprise one or more zones including a third precursor zone 547, a second inert gas zone 549, and a fourth precursor zone 551. The cured film 501 may be received in the second deposition chamber 545 by a secondary guide roll 553 disposed within the second inert gas zone 549 of the second deposition chamber 445. From here, the cured film 501 may be laterally advanced through the zones 547, 549, 551 of the second deposition chamber 545 in a serpentine pathway. As the cured film 501 traverses the second deposition chamber 545, a second barrier layer may be deposited at the surface of the cured film 501. A second exit guide roll 555 may convey the cured film 501, now including a second barrier layer adjacent the quantum dot layer, to an outlet 558 of the second deposition chamber 545. A rewinder 557 may be disposed adjacent an outlet 558 of the second deposition chamber 545 to coil the cured film 501 into a rolled product.

[0052] The position of unwinder that feeds the substrate for the serially aligned processes disclosed herein may affect overall efficiency of system to form the film. For example, the unwinder may be disposed within the vacuum chamber for spatial atomic layer deposition. To change the substrate roll, the vacuum pressure is broken, which can be time consuming and extend processing time. In a further example, and as presented in FIGs. 4 and 5 of exemplary aspects of the present disclosure, the unwinder may be disposed outside of the deposition chamber. Positioning the unwinder outside of the deposition chamber may allow for vacuum pressure to remain unbroken helps maintain a shorter processing time.

[0053] A water vapor transmission rate (WVTR) may be a measure of the barrier performance of the films prepared according to the systems and methods described herein. A QD film prepared herein may exhibit a WVTR of from about 10^"1 g/m²/day to about 10^"6 g/m²/day when tested according to a calcium (Ca) test. The calcium test utilizes the reaction of calcium with water and oxygen and the conductive behavior of calcium as it offers resistance against applied voltage. The electrical Ca test measures the change of electrical conductance when calcium is oxidized (to either insulating calcium oxide CaO or calcium hydroxide Ca(OH)2) in the presence of water or oxygen. Performance of a given barrier layer may be evaluated based upon how much oxygen or water permeates the barrier layer and reacts with the calcium.

[0054] In many aspects, the QD films formed herein may be useful in display and imaging applications. Non-limiting examples of fields which may use the films formed herein include lighting applications and devices such as light emitting diodes (LEDs); solar cells for an efficient conversion of sunlight into energy; medical diagnoses and imaging such as targeting and labelling membrane proteins, cell illumination, biological receptor binding, and cancer cell imaging. In some aspects, the barrier layer may comprise a diffusing function to facilitate uniform brightness at the film for certain lighting applications.

Examples

[0055] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the compounds, compositions, articles, devices and/or methods claimed herein are made and evaluated, and are intended to be purely exemplary and are not intended to limit the disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for.

[0056] There are numerous variations and combinations of reaction conditions, e.g., component concentrations, desired solvents, solvent mixtures, temperatures, pressures and other reaction ranges and conditions that can be used to optimize the product purity and yield obtained from the described process. Only reasonable and routine experimentation will be required to optimize such process conditions.

[0057] FIG. 6 provides a diagram with two views (front and side) of the calcium test device used to determine the WVTR for a film prepared according to the system and methods provided herein. The barrier film for testing may be attached to a sheet of calcium metal fitted to a pair of electrodes at a glass substrate. Upon exposure to water, calcium transforms from an opaque conductive metal to a transparent resistive oxide material. Conductance across the calcium is measured and is used to determine barrier permeation over time. As shown, FIG. 7 presents the observed normalized conductance 1/R (where R refers to resistance) as a function of time (hours) for two harrier films prepared according to the present disclosure. Normalized conductance over time was obtained via a calcium test (e.g., the National Renewable Energy Laboratory (NREL) e-Ca test) to provide the WVTR for the barrier films in FIG. 7.

[0058] A lower value indicates better performance of the barrier because less oxygen or water has permeated the barrier layer to react with the calcium. In the conductance-time curve, better barrier performance corresponds to the curve that takes more time to reach zero conductance. Zero conductance indicates that there is no calcium conducting in the measuring device and thus, more gas has permeated the barrier layer. A poor barrier layer allows the permeation of more gas and accordingly reaches zero conductance faster than a more efficient barrier layer would. A 10^"3 g/m²/day performance is acceptable for a barrier used for QD films. Both barrier films exhibited less than 10^"' g/m²/day performance.

Definitions

[0059] It is to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. As used in the specification and in the claims, the term "comprising" can include the aspects "consisting of and "consisting essentially of." Unless defined otherwise, 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 disclosure belongs. In this specification and in the claims which follow, reference will be made to a number of terms which shall be defined herein. [0060] As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural equivalents unless the context clearly dictates otherwise. Thus, for example, reference to "a polycarbonate polymer" includes mixtures of two or more polycarbonate polymers.

[0061] As used herein, the term "combination" is inclusive of blends, mixtures, alloys, reaction products, and the like.

[0062] Ranges can be expressed herein as from one value (first value) to another value (second value). When such a range is expressed, the range includes in some aspects one or both of the first value and the second value. Similarly, when values are expressed as approximations, by use of the antecedent 'about,' it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as "about" that particular value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0063] As used herein, the terms "about" and "at or about" mean that the amount or value in question can be the designated value, approximately the designated value, or about the same as the designated value. It is generally understood, as used herein, that it is the nominal value indicated ±5% variation unless otherwise indicated or inferred. The term is intended to convey that similar values promote equivalent results or effects recited in the claims. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. In general, an amount, size, formulation, parameter or other quantity or characteristic is "about" or "approximate" whether or not expressly stated to be such. It is understood that where "about" is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0064] Disclosed are the components to be used to prepare the compositions of the disclosure as well as the compositions themselves to be used within the methods disclosed herein. These and other materials are disclosed herein, and it is understood that when combinations, subsets, interactions, groups, etc. of these materials are disclosed that while specific reference of each various individual and collective combinations and permutation of these compounds cannot be explicitly disclosed, each is specifically contemplated and described herein. For example, if a particular compound is disclosed and discussed and a number of modifications that can be made to a number of molecules including the compounds are discussed, specifically contemplated is each and every combination and permutation of the compound and the modifications that are possible unless specifically indicated to the contrary. Thus, if a class of molecules A, B, and C are disclosed as well as a class of molecules D, E, and F and an example of a combination molecule, A-D is disclosed, then even if each is not individually recited each is individually and collectively contemplated meaning combinations, A-E, A-F, B-D, B-E, B-F, C-D, C-E, and C-F are considered disclosed. Likewise, any subset or combination of these is also disclosed. Thus, for example, the sub-group of A-E, B-F, and C- E would be considered disclosed. This concept applies to all aspects of this application including, but not limited to, steps in methods of making and using the compositions of the disclosure. Thus, if there are a variety of additional steps that can be performed it is understood that each of these additional steps can be performed with any specific aspect or combination of aspects of the methods of the disclosure.

[0065] As used herein, the term "transparent" or "optically clear" means that the level of transmittance for a disclosed composition is greater than 50%. In some aspects, the transmittance can be at least 60%, 70%, 80%, 85%, 90%, or 95%, or any range of transmittance values derived from the above exemplified values. In the definition of "transparent", the term "transmittance" refers to the amount of incident light that passes through a sample measured in accordance with ASTM D1003 at a thickness of 3.2 millimeters.

[0066] The term "cure" and its derivatives may refer to a process that causes a chemical change, e.g., a reaction via consumption of water, to solidify a film layer or increase its viscosity.

[0067] Unless otherwise stated to the contrary herein, all test standards are the most recent standard in effect at the time of filing this application.

Aspects

[0068] The present disclosure comprises at least the following aspects.

[0069] Aspect 1A. A process of forming a quantum dot film comprising: continuously feeding a substrate into a vacuum deposition chamber, the deposition chamber comprising at least a first precursor zone, a purge zone, and a second precursor zone; advancing the substrate through at least the first precursor zone, the purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate to provide a layered substrate; conveying the layered substrate through a pressure gradient system, wherein the pressure gradient system adjusts pressure at the substrate so that the pressure at the substrate is greater than a pressure within the vacuum deposition chamber; applying a quantum dot resin coating to the layered substrate via a non-contact type coating process to provide a quantum dot resin coated substrate; and curing the quantum dot resin coated substrate in a curing zone to provide the quantum dot film.

[0070] Aspect IB. A process of forming a quantum dot film consisting essentially of:

continuously feeding a substrate into a vacuum deposition chamber, the deposition chamber comprising at least a first precursor zone, a purge zone, and a second precursor zone;

advancing the substrate through at least the first precursor zone, the purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate to provide a layered substrate; conveying the layered substrate through a pressure gradient system, wherein the pressure gradient system adjusts pressure at the substrate so that the pressure at the substrate is greater than a pressure within the vacuum deposition chamber; applying a quantum dot resin coating to the layered substrate via a non-contact type coating process to provide a quantum dot resin coated substrate; and curing the quantum dot resin coated substrate in a curing zone to provide the quantum dot film.

[0071] Aspect 1C. A process of forming a quantum dot film consisting of: continuously feeding a substrate into a vacuum deposition chamber, the deposition chamber comprising at least a first precursor zone, a purge zone, and a second precursor zone; advancing the substrate through at least the first precursor zone, the purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate to provide a layered substrate; conveying the layered substrate through a pressure gradient system, wherein the pressure gradient system adjusts pressure at the substrate so that the pressure at the substrate is greater than a pressure within the vacuum deposition chamber; applying a quantum dot resin coating to the layered substrate via a non-contact type coating process to provide a quantum dot resin coated substrate; and curing the quantum dot resin coated substrate in a curing zone to provide the quantum dot film.

[0072] Aspect 2. The process of any of aspects 1A-1C, wherein the quantum dot film exhibits a water vapor transmission rate of between about 10^"1 g/m²/day to about 10^"6 g/m²/day. [0073] Aspect 3. The process of any of aspects 1A-2, further comprising continuously feeding the quantum dot resin coated substrate into a second vacuum deposition chamber, the second deposition chamber comprising at least a third precursor zone, a second purge zone, and a fourth precursor zone.

[0074] Aspect 4. The process of any of aspects 1A-3, wherein the pressure gradient system comprises sequentially decreasing pressure zones such that a first pressure zone has a pressure of about 10 Torr, a subsequent second pressure zone has a pressure of about 100 Torr, and a subsequent third pressure zone has a pressure of about 760 Torr.

[0075] Aspect 5. The process of any of aspects 1A-4, wherein the first precursor zone comprises water or another hydrolyzing compound.

[0076] Aspect 6. The process of any of aspects 1A-5, wherein the second precursor zone comprises trimethylaluminum or titanium tetrachloride.

[0077] Aspect 7. The process of any of aspects 1A-6, wherein the one or more layers delivered to the substrate in the deposition chamber has a thickness of between about 5 μπι and about 50 nm.

[0078] Aspect 8. The process of any of aspects 1A-7, wherein the non-contact type coating process comprises a slot die configured to deliver a non-pulsing, constant feed of the quantum dot resin coating to the layered substrate.

[0079] Aspect 9. The process of any of aspects 1A-8, wherein the quantum dot resin coating has a thickness of between about 1 μπι and about 100 μπι.

[0080] Aspect 10. The process of any of aspects 1A-9, wherein the quantum dot resin coating comprises gallium arsenide, cadmium selenide, indium phosphide quantum dots, indium quantum dots, cadmium selenide, cadmium sulfide, or zinc sulfide quantum dot resin or a combination thereof.

[0081] Aspect 11. The process of any of aspects 1A-9, wherein the quantum dot resin coating comprises a cadmium selenide, cadmium sulfide, or zinc sulfide quantum dot resin, or a combination thereof.

[0082] Aspect 12. The process of any of aspects 1A-9, wherein the quantum dot resin coating is comprises indium quantum dots.

[0083] Aspect 13. The process of any of aspects 1A-12 wherein the curing zone comprises a thermal curing process or an ultraviolet curing process.

[0084] Aspect 14. The process of any of aspects 1A-13, wherein the process further comprises a second curing zone. [0085] Aspect 15. The process of any of aspects 1A-14, wherein the one or more zones of the deposition chambers are separated by a gas curtain.

[0086] Aspect 16. The process of any of aspects 1A-15, wherein the purge zone comprises an inert gas.

[0087] Aspect 17. The process of any of aspects 1A-16, wherein the substrate comprises polyethylene terephthalate, polycarbonate, or polyimide or a combination thereof.

[0088] Aspect 18. The process of any of aspects 1A-17, wherein the substrate is advanced at a process speed between about 5 to about 100 meters per minute.

[0089] Aspect 19. The process of any of aspects 3-18, wherein the second purge zone comprises an inert gas.

[0090] Aspect 20. The process of any of aspects 3-19, wherein the third precursor zone comprises trimethylaluminum or titanium tetrachloride.

[0091] Aspect 21. The process of any of aspects 3-20, wherein the fourth precursor zone comprises trimethylaluminum or titanium tetrachloride.

[0092] Aspect 22. An article formed from the quantum resin coated substrate of any of aspects 1A-21.

[0093] Aspect 23A. A roll-to-roll system for a preparation of a layered substrate, the system comprising: a vacuum deposition chamber comprising at least a first precursor zone, a first purge zone, and a second precursor zone; one or more conveying rolls disposed within the deposition chamber, the one or more conveying rolls configured to advance a substrate through at least the first precursor zone, the first purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate; a pressure gradient system disposed adjacent the deposition chamber, wherein the pressure gradient is configured to effect an increase in pressure at the surface of the substrate; a non-contact type, solution coating apparatus configured to receive the substrate from the pressure gradient and wherein the non- contact type, solution coating apparatus is configured to deliver a quantum dot resin coating to the one or more layers of the substrate; and a curing zone configured to receive the substrate from the non-contact type solution coating apparatus and wherein the curing zone is configured to cure at least the one or more layers or the quantum dot resin coating at the surface of the substrate.

[0094] Aspect 23B. A roll-to-roll system for a preparation of a layered substrate, the system consisting essentially of: a vacuum deposition chamber consisting essentially of at least a first precursor zone, a first purge zone, and a second precursor zone; one or more conveying rolls disposed within the deposition chamber, the one or more conveying rolls configured to advance a substrate through at least the first precursor zone, the first purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate; a pressure gradient system disposed adjacent the deposition chamber, wherein the pressure gradient is configured to effect an increase in pressure at the surface of the substrate; a non-contact type, solution coating apparatus configured to receive the substrate from the pressure gradient and wherein the non-contact type, solution coating apparatus is configured to deliver a quantum dot resin coating to the one or more layers of the substrate; and a curing zone configured to receive the substrate from the non-contact type solution coating apparatus and wherein the curing zone is configured to cure at least the one or more layers or the quantum dot resin coating at the surface of the substrate.

[0095] Aspect 23 C. A roll-to-roll system for a preparation of a layered substrate, the system consisting of: a vacuum deposition chamber consisting of at least a first precursor zone, a first purge zone, and a second precursor zone; one or more conveying rolls disposed within the deposition chamber, the one or more conveying rolls configured to advance a substrate through at least the first precursor zone, the first purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate; a pressure gradient system disposed adjacent the deposition chamber, wherein the pressure gradient is configured to effect an increase in pressure at the surface of the substrate; a non-contact type, solution coating apparatus configured to receive the substrate from the pressure gradient and wherein the non- contact type, solution coating apparatus is configured to deliver a quantum dot resin coating to the one or more layers of the substrate; and a curing zone configured to receive the substrate from the non-contact type solution coating apparatus and wherein the curing zone is configured to cure at least the one or more layers or the quantum dot resin coating at the surface of the substrate.

[0096] Aspect 24. The roll-to-roll system of any of aspects 23A-23C, wherein the non- contact type coating apparatus comprises a slot die configured to deliver a non-pulsing, constant feed of the quantum dot resin coating to the layered substrate.

[0097] Aspect 25. The roll-to-roll system of any one of aspects 23 A-24, wherein pressure gradient system comprises sequentially decreasing pressure zones such that a first pressure zone has a pressure of about 10 Torr, a subsequent second pressure zone has a pressure of about 100 Torr, and a subsequent third pressure zone has a pressure of about 760 Torr

[0098] Aspect 26A. A roll-to-roll process for preparing a film, the process comprising: depositing a barrier layer at a surface of a substrate to provide a layered substrate, wherein the barrier layer is applied via a spatial atomic layer deposition process, wherein the spatial atomic layer deposition process occurs under vacuum pressure, and wherein the substrate is provided from a substrate roll; subjecting the layered substrate to a pressure gradient system configured to effect an increase in pressure at the surface of the substrate to which the barrier layer has been deposited; depositing a quantum dot layer at a surface of the barrier layer via a solution dot coating process to provide a quantum dot film; and subjecting the quantum dot film to a curing process to cure at least the barrier layer and the quantum dot layer deposited at the barrier layer.

[0099] Aspect 26B. A roll-to-roll process for preparing a film, the process consisting essentially of: depositing a barrier layer at a surface of a substrate to provide a layered substrate, wherein the barrier layer is applied via a spatial atomic layer deposition process, wherein the spatial atomic layer deposition process occurs under vacuum pressure, and wherein the substrate is provided from a substrate roll; subjecting the layered substrate to a pressure gradient system configured to effect an increase in pressure at the surface of the substrate to which the barrier layer has been deposited; depositing a quantum dot layer at a surface of the barrier layer via a solution dot coating process to provide a quantum dot film; and subjecting the quantum dot film to a curing process to cure at least the barrier layer and the quantum dot layer deposited at the barrier layer.

[00100] Aspect 26C. A roll-to-roll process for preparing a film, the process consisting of: depositing a barrier layer at a surface of a substrate to provide a layered substrate, wherein the barrier layer is applied via a spatial atomic layer deposition process, wherein the spatial atomic layer deposition process occurs under vacuum pressure, and wherein the substrate is provided from a substrate roll; subjecting the layered substrate to a pressure gradient system configured to effect an increase in pressure at the surface of the substrate to which the barrier layer has been deposited; depositing a quantum dot layer at a surface of the barrier layer via a solution dot coating process to provide a quantum dot film; and subjecting the quantum dot film to a curing process to cure at least the barrier layer and the quantum dot layer deposited at the barrier layer.

[00101] Aspect 27. The roll-to-roll process of any of aspects 26A-26C, further comprising depositing a second barrier layer at the surface of the quantum dot layer prior to subjecting the quantum dot film to the curing process.

[00102] Method examples described herein can be machine or computer-implemented at least in part. Some examples can include a computer-readable medium or machine- readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Further, in an example, the code can be tangibly stored on one or more volatile, non-transitory, or nonvolatile tangible computer-readable media, such as during execution or at other times.

Examples of these tangible computer-readable media can include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memories (RAMs), read only memories (ROMs), and the like.

[00103] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other aspects can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed aspect. Thus, the following claims are hereby incorporated into the Detailed Description as examples or aspects, with each claim standing on its own as a separate aspect, and it is contemplated that such aspects can be combined with each other in various combinations or permutations. The scope of the disclosure should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

[00104] While typical aspects have been set forth for the purpose of illustration, the foregoing descriptions should not be deemed to be a limitation on the scope herein.

Accordingly, various modifications, adaptations, and alternatives can occur to one skilled in the art without departing from the spirit and scope herein.

[00105] It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. Other aspects of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims. [00106] The patentable scope of the disclosure is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

CLAIMS is claimed is:

A process of forming a quantum dot film comprising:

continuously feeding a substrate into a vacuum deposition chamber, the vacuum

deposition chamber comprising at least a first precursor zone, a purge zone, and a second precursor zone;

advancing the substrate through at least the first precursor zone, the purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate to provide a layered substrate;

conveying the layered substrate through a pressure gradient system, wherein the pressure gradient system adjusts pressure at the substrate so that the pressure at the substrate is greater than a pressure within the vacuum deposition chamber;

applying a quantum dot resin coating to the layered substrate via a non-contact type coating process to provide a quantum dot resin coated substrate; and curing the quantum dot resin coated substrate in a curing zone to provide the quantum dot film.

The process of claim 1, wherein the quantum dot film exhibits a water vapor transmission rate of between about 10^"1 g/m²/day to about 10^"6 g/m²/day.

The process of any of claims 1-2, further comprising continuously feeding the quantum dot resin coated substrate into a second vacuum deposition chamber, the second vacuum deposition chamber comprising at least a third precursor zone, a second purge zone, and a fourth precursor zone.

The process of any of claims 1-3, wherein the pressure gradient system comprises sequentially decreasing pressure zones such that a first pressure zone has a pressure of about 10 Torr, a subsequent second pressure zone has a pressure of about 100 Torr, and a subsequent third pressure zone has a pressure of about 760 Torr.

The process of any of claims 1-4, wherein the first precursor zone comprises water or another hydrolyzing compound.

6. The process of any of claims 1-5, wherein the second precursor zone comprises trimethylaluminum or titanium tetrachloride.

7. The process of any of claims 1-6, wherein the one or more layers delivered to the substrate in the vacuum deposition chamber has a thickness of between about 5 μιη and about 50 nm.

8. The process of any of claims 1-7, wherein the non-contact type coating process

comprises a slot die configured to deliver a non-pulsing, constant feed of the quantum dot resin coating to the layered substrate.

9. The process of any of claims 1-8, wherein the quantum dot resin coating has a

thickness of between about 1 μπι and about 100 μπι.

10. The process of any of claims 1-9, wherein the quantum dot resin coating comprises gallium arsenide, cadmium selenide, indium phosphide quantum dots, indium quantum dots, cadmium selenide, cadmium sulfide, or zinc sulfide quantum dot resin or a combination thereof.

11. The process of any of claims 1-10 wherein the curing zone comprises a thermal curing process or an ultraviolet curing process.

12. The process of any of claims 1-11, wherein the process further comprises a second curing zone.

13. The process of any of claims 1-12, wherein the purge zone comprises an inert gas.

14. The process of any of claims 3-12, wherein the second purge zone comprises an inert gas.

15. The process of any of claims 1-14, wherein the substrate comprises polyethylene terephthalate, polycarbonate, or polyimide or a combination thereof.

16. The process of any of claims 1-15, wherein the substrate is advanced at a process speed between about 5 to about 100 meters per minute.

17. An article formed from the quantum dot resin coated substrate of any of claims 1-16.

18. A roll-to-roll system for a preparation of a layered substrate, the roll-to-roll system comprising:

a vacuum deposition chamber comprising at least a first precursor zone, a first purge zone, and a second precursor zone; one or more conveying rolls disposed within the vacuum deposition chamber, the one or more conveying rolls configured to advance a substrate through at least the first precursor zone, the first purge zone, and the second precursor zone to deliver one or more layers to a surface of the substrate;

a pressure gradient system disposed adjacent the deposition chamber, wherein the pressure gradient system is configured to effect an increase in pressure at the surface of the substrate;

a non-contact type, solution coating apparatus configured to receive the substrate from the pressure gradient and wherein the non-contact type solution coating apparatus is configured to deliver a quantum dot resin coating to the one or more layers of the substrate; and

a curing zone configured to receive the substrate from the non-contact type solution coating apparatus and wherein the curing zone is configured to cure at least the one or more layers or the quantum dot resin coating at the surface of the substrate.

The roll-to-roll system of claim 18, wherein the non-contact type coating apparatus comprises a slot die configured to deliver a non-pulsing, constant feed of the quantum dot resin coating to the layered substrate.

The roll-to-roll system of any one of claims 18-19, wherein pressure gradient system comprises sequentially decreasing pressure zones such that a first pressure zone has a pressure of about 10 Torr, a subsequent second pressure zone has a pressure of about 100 Torr, and a subsequent third pressure zone has a pressure of about 760 Torr.