WO2018109662A1

WO2018109662A1 - Fabrication of patterned transparent electrodes for oled lighting applications

Info

Publication number: WO2018109662A1
Application number: PCT/IB2017/057842
Authority: WO
Inventors: Sang Hoon Kim; Byungwan LIM; Eun-Uk KIM
Original assignee: SABIC Global Technologies BV
Current assignee: SABIC Global Technologies BV
Priority date: 2016-12-12
Filing date: 2017-12-12
Publication date: 2018-06-21
Anticipated expiration: 2019-06-12

Abstract

A process for fabricating a conductive pattern (120) on a substrate (110) includes forming a curable resin coating (130) on a substrate (110), depositing a plurality of metal nanowires (140) on the curable resin coating (130) and embedding the metal nanowires (140) in the curable resin coating (130). The process further includes applying a patterning mask (160) over the curable resin coating (130) wherein one or more portions of the curable resin coating (130A) are exposed and one or more portions of the curable resin coating (130B) are masked and curing the one or more exposed portions (130A) of the curable resin coating (130) to form the conductive pattern (120).

Description

FABRICATION OF PATTERNED TRANSPARENT

ELECTRODES FOR OLED LIGHTING APPLICATIONS

Technical Field

[0001] The present disclosure relates to transparent patterned conductive films for organic light- emitting diodes and more particularly to a process of fabricating the same.

Background

[0002] Today, organic light emitting diodes (OLEDs) are increasingly used in lighting applications because they are more energy efficient than other conventional lighting sources. OLEDs typically have a stacked structure composed of one or more organic layers positioned between two electrodes. At least one of the two electrodes, either the anode or the cathode electrode is formed from a transparent conductive material, which enables the light emitted from the OLED to be visible.

[0003] The transparent conductive material used as an electrode should possess certain properties such as low resistivity and high optical transmittance to produce an OLED device with desirable performance. Indium tin oxide (ITO) is a transparent electrode material that is useful in OLED applications due to its high transparency in the visible wavelength range. For example, ITO is commonly used in many liquid crystal display LCD applications. Transparent conductive oxides, such as ITO, however, are problematic for flexible OLED devices because they are brittle and prone to cracking under stress. The cracking reduces the conductivity of the electrode and ultimately may degrade the OLED. As a result, this particular drawback has limited the use of ITO in flexible OLEDs.

[0004] Materials such as silver nanowires (AgNW) or other metal nanowires, metal

nanoparticles, carbon nanotubes, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), and graphene have emerged as alternatives to ITO for flexible OLED

applications. These materials possess advantageous properties such as strong adhesion with the substrate, wettability, and high glass transition temperatures that make them desirable as electrode materials. Silver nanowire, however, has emerged as the most promising alternative to ITO due to its high conductivity and optical transmittance. Silver nanowire has also

demonstrated the appropriate mechanical flexibility as shown by its bending properties and the electrical resistivity (10 ohm per square (ohm/sq)) needed for large-scale production.

[0005] Despite the aforementioned advantages, electrodes formed using silver nanowires suffer from challenges associated with higher surface roughness. For example, when silver nanowires are deposited on a surface the nanowires overlap each other creating protrusions and causing surface roughness. While these portions of overlapping nanowires increase the conductivity of the electrode, higher surface roughness lowers the efficiency and the stability of the overall device. Therefore, it is important that the surface characteristics of electrodes formed using silver nanowire are improved to allow for stable and efficient devices.

[0006] Furthermore, many display and electronic devices require that the electrode is patterned. Conventional methods to pattern an electrode include photolithography and laser patterning. Both of these methods, however, have drawbacks. For example, photolithography is generally known to be an expensive and time-consuming process involving many steps. Photolithography also tends to produce an electrode that has lower electrical properties. Laser patterning is expensive and tends to generate debris that may damage the electrode. Electrodes patterned using laser patterning suffers from problems associated with pattern accuracy. Therefore, improved processes of patterning electrodes are also needed to produce low cost, high quality devices.

[0007] One approach to improving the surface roughness of silver nanowires has been to form a top coating of PEDOT:PSS over the silver nanowires. The acidity of the PEDOT:PSS, however, tends to negatively affect the properties of the silver nanowire and the device stability.

Electrodes formed using hybrid solutions that combine silver nanowires and PEDOT:PSS have also been tested and produce similar results. Another approach to improving surface roughness involves welding to fill in the existing gaps in a deposited layer of silver nanowire. The welding process may improve surface roughness, but it significantly increases the production costs and complexity of fabrication. Furthermore, none of these approaches address the need to fabricate a patterned electrode using silver nanowires.

[0008] These and other shortcomings are addressed by aspects of the present disclosure. Summary

[0009] In accordance with one aspect of the disclosure, a process for fabricating a patterned conductive film on a substrate is provided. The process includes (a) forming a curable resin coating on the substrate; (b) depositing a plurality of metal nanowires on the curable resin coating; (c) embedding one or more of the plurality of metal nanowires in the curable resin coating; (d) applying a patterning mask over the curable resin coating wherein one or more portions of the curable resin coating are exposed and one or more portions of the curable resin coating are masked; and (e) curing the one or more exposed portions of the curable resin coating to form the patterned conductive film.

[0010] In accordance with another aspect of the disclosure, a process for fabricating a patterned conductive film on a substrate is provided. The process includes (a) forming a curable resin coating on the substrate, wherein the curable resin coating comprises an ultraviolet sensitive photopolymer; (b) depositing a plurality of silver nanowires on the curable resin coating; (c) heating the substrate to soften or melt the curable resin coating, wherein one or more of the plurality of silver nanowires become embedded in the curable resin coating; (d) applying a patterning mask over the curable resin coating, wherein one or more portions of the curable resin coating are exposed and one or more portions of the curable resin coating are masked; (e) applying ultraviolet light to cure the one or more exposed portions of the curable resin coating; (f) removing the patterning mask; and (g) applying one or more solvents to remove the uncured portions of the curable resin coating.

Brief Description of the Drawings

[0011] 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:

[0012] FIG. 1 is a cross-sectional view of the conductive patterned film on a substrate according to one aspect of the present disclosure.

[0013] FIG. 2A is a schematic illustration of the curable resin coating formed on the substrate according to one aspect of the present disclosure.

[0014] FIG. 2B is a schematic illustration of the metal nanowires on the curable resin coating according to one aspect of the present disclosure.

[0015] FIG. 2C is a schematic illustration of the metal nanowires embedded in the curable resin coating according to one aspect of the present disclosure. [0016] FIG. 2D is a schematic illustration of the patterning mask positioned over the curable resin coating according to one aspect of the present disclosure.

[0017] FIG. 2E is a schematic illustration of the conductive pattern on the substrate with the uncured portions of the resin coating according to one aspect of the present disclosure.

[0018] FIG. 2F is a schematic illustration of the conductive pattern on the substrate after the uncured portions of the resin coating have been removed according to one aspect of the present disclosure.

Detailed Description

[0019] The present disclosure provides a process for producing a patterned conductive film composed of metal nanowires, such as silver nanowires. The process features using an ultraviolet sensitive curable resin coating with silver nanowires to form the patterned conductive film. This patterned conductive film is particularly useful as an electrode.

[0020] FIG. 1 illustrates a cross-sectional view of a patterned conductive film 100 or electrode formed using the process according to one aspect of the present disclosure. As shown in FIG. 1, the patterned conductive film 100 may have a stacked layered structure. The patterned conductive film 100 includes a substrate 110 and a transparent conductive layer 120 disposed on the substrate 110. The transparent conductive layer 120 consists of a curable resin coating 130 and a plurality of metal nanowires 140. The transparent conductive layer 120 is patterned. The patterning, however, is not shown in FIG. 1 for clarity purposes. The patterned conductive film 100 may also include protective film layers 150. For example, a protective film layer 150 may^¬ be disposed on the transparent conductive layer 120 opposite the substrate 110. A protective film layer 150 may also be disposed on the substrate 1 10 opposite the transparent conductive layer 120.

[0021] FIGS. 2A-2F provide a cross-sectional illustration of the various process steps that may^¬ be used to fabricate a patterned conductive film 100 according to one aspect of the disclosure. The patterned conductive film 100 may be used as an electrode, including an anode electrode or a cathode electrode. In one aspect, the patterned conductive film 100 may be transparent. The patterned conductive film 100 may be used to form an OLED or a photovoltaic device. Other uses for the patterned conductive film 100, however, are contemplated and the present disclosure is not limited in this regard. [0022] The process may initially begin with forming a curable resin coating 130 on a substrate 110. FIG. 2A sho ws the curable resin coating 130 disposed on the surface of the substrate 110.

[0023] The substrate 110 may comprise any suitable material known in the art. Suitable substrate materials may include, but are not limited to, glass, plastics, semiconductor materials such as silicon, and ceramics. Specific examples of the substrate 110 may include, but are not limited to a plate or a foil of metal such as aluminum (including aluminum alloy), zinc, copper and iron; a film made of plastic such as cellulose acetate, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene, polyester, polyamide, poiyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetai, aramid and polyphenyiene sulfide: and paper having plastic (polyethylene, polypropylene, polystyrene, or the like) laminated thereon or paper coated with plastic (polyethylene, polypropylene, polystyrene, or the like), paper or a plastic film having the above-mentioned metal laminated thereon or vapor-deposited thereon. In some aspects of the disclosure, suitable polymeric materials for the substrate 110 include, but are not limited to polyethylene terephthalate, poly methylacrylate, polymethyl methacrylate, polyacrylate copolymer, polyurethane, polyurethane copolymer, cellulose acetate, polystyrene, polystyrene copolymer, poiyimide and mixtures thereof.

[0024] The thickness of the substrate 1 10 is not particularly limited. For example, the substrate 1 0 thickness may be 300 micrometers (μτη) or less, more preferably 200 um or less, and even more preferably 100 μτη or less. In some aspects of the disclosure, the substrate 1 10 thickness may range from 100 μτη to 50 μιτι. in some aspects of the disclosure, the substrate 110 thickness may range from 10 μπι to 50 μτη.

[0025] In some aspects of the disclosure, the substrate 1 10 is flexible. Polymeric materials that are generally transparent as well as flexible may be used to form the substrate 110. A transparent flexible substrate 1 10 may be particularly useful for OLED lighting applications such that light generated by the OLED may pass through the OLED. In one aspect of the disclosure, polyethylene terephthalate is used to form the substrate 110. The polyethylene terephthalate substrate 110 may be used to form a patterned conductive film 100.

[0026] The curable resin coating 130 may be formed by preparing a curable resin composition and applying the curable resin composition to the substrate 1 10. The curable resm composition may be a solution formed from mixing one or more polymers with one or more solvents. The solution may then be applied to the substrate 110 and dried. The curable resin composition generally includes a polymeric composition capable of being cured at an acceptable rate. Faster curing rates may be more desirable for some commercial applications.

[0027] The curable resin composition may be applied to the substrate 1 10 by spraying, dipping, roll-coating or roll-to-roll coating the curable resin material onto the surface of the substrate 110. In one aspect of the present disclosure, the curable resin coating is applied to the electrode by- applying a thin layer of the resin material onto the substrate 110 by any well-known methods such as spraying, dipping, roll-coating and the like. A sufficient amount of the resin material should be applied to the substrate 110 to provide a thickness suitable for embedding the metal nanowires 140 as described. Other suitable means of applying a surface coating known to those skilled in the art may be used as well. In one aspect of the disclosure, the curable resin coating 130 may be applied to the substrate 110 using a roll-to-roll coating process. The curable resin coating 130 may be dried and rinsed once the curable resin coating 130 has been applied to the substrate 110.

[0028] The curable resin coating 130 thickness is not limited. The thickness of the curable resin coating 130, however, should be sufficient to embed the metal nanowires 140 into the resin coating to reduce the surface roughness. In one aspect, the curable resin coating 130 may be at leas 50 μτη thick. Application methods may be repeated to form thicker curable resin coatings 130 if needed.

[0029] The curable resin coating 130 generally should not introduce surface roughness to the patterned conductive film 100. The curable resin coating 130 is generally used to improve the surface characteristics of the resulting patterned conductive film 100. The application methods should generally reflect this concept.

[0030] The curable resin coating 130 may be applied by any means suitable to deposit the curable resin composition onto the substrate 110 surface. A solution may be prepared by dissolving the curable resin polymer composition in one or more solvents. The curable resin composition may then be applied to the substrate 110 surface. The solvent! s) may be removed by evaporating or drying the curable resin composition resulting in the curable resin coating 30. It may also be possible to prepare a solution of monomers that may be polymerized to form the curable resin coating 30. The monomer solution may then be used to coat the substrate 110 surface. Polymerization of the monomer solutions may occur by applying heat and/or light to the monomer solution. [0031] The curable resm coating 130 may be disposed on the surface of the substrate 110 upon which the pattern is to be formed. The curable resin coating 130 may be composed of a resm material suitable for forming the patterned electrode. Accordingly, any resm material may be employed as the curable resin coating 130 as long as it allows for the embedding of the metal nanowires 140.

[0032] The resm material is generally film forming and able to sufficiently adhere to the substrate 110. The resin material may also be a thermoplastic or a thermosetting polymer. The resm material may have a glass transition temperature that is suitable for heating the substrate 110 such that the resin material softens or melts to receive the metal nanowires 140.

[0033] In some aspects of the present disclosure, the curable resin coating may be ultraviolet sensitive such that the resin material may cure when exposed to ultraviolet light. For example, the photopolymer may be capable of absorbing light in a wavelength in the range from 180 nanometers (nm) to 500 nm. The photopolymer may be capable of absorbing light in a wavelength in the range from 320 nm to 400 nm.

[0034] In one aspect of the disclosure, the resin material may include a photopolymer, in particular an ultraviolet sensitive photopolymer. The resin material may include other polymers in addition to other polymers. Alternatively, the resin material may consist essentially of a photopolymer. In other aspects of the disclosure, the resm material may include a polymer binder and a photoinitiator. The photoimtiator may be ultraviolet light sensitive.

[0035] The photopolymer may include for example a polymer having diazo functional groups or styryl functional groups. The photopolymer may include a styryl pyridinium or a styryl pyridinium derivative. The photopolymer may also include poly(vinyl pyridine). The photopolymer may also be a polyvinyl alcohol based photopolymer.

[0036] The curable resm material may include a polymer binder and a photoinitiator. Suitable examples of the polymer binder in the resm material may mclude, but are not limited to, silicone resins, epoxy resins, polyallylate resins, PET modified polyallyiate resins, polycarbonate resins (PC), cyclic olefins, polyethylene terephthalate resins (PET), polymethylmethacrylate resins (P MA) and mixtures thereof. In one aspect of the present disclosure, the polymer binder may include a polyester acrylate, an epoxy acrylate, a urethane acrylate, a silicone resin acrylate or mixtures thereof. [0037] In one aspect of the present disclosure, the thickness of the curable resin coating 130 may be sufficient to embed the metal nanowires 140 into the curable resin coating 130. The metal nano wires 140 may be embedded into the curable resm coating 130 such that the surface roughness of the curable resin coating 130 may be reduced. The reduced surface roughness of the resulting structure is highly advantageous in patterning electrodes and in applications such as OLED fabrication.

[0038] Once the substrate 110 has been coated with the curable resin, a plurality of metal nanowires 140 are deposited on the curable resm coating 130. The metal nanowires 140 may be deposited on the curable resin coating 130 such that the metal nanowires 140 are dispersed uniformly across at least a portion of the curable resin coating 130. The metal nanowires 140 are used to provide conductive properties to the resulting patterned conductive film 100. The metal nanowires 140 may also be transparent such that a transparent patterned conductive film 100 is formed.

[0039] The metal nanowires 140 may also include metal nanorods, nanostrands, nanowires, or a mixture thereof. As used herein, the term nanowire is meant to collectively refer to nanorods, nanostrands, and nanowires. The metal nanowires 140 may comprise at least one of silver, gold, copper, nickel, rhodium, palladium, platinum, aluminum, and/or alloys thereof. These metals may generally be preferred because of their strong conducti ve properties. Metals used for the metal nanowires 140 may include, but are not limited to, copper, silver, aluminum and alloys thereof. In one aspect of the disclosure, the metal nanowires 140 are silver nanowires (AgNW). One advantage of the process according to the present disclosure is that silver nanowires may be used to form a transparent conductive layer 120 on a flexible substrate 110.

[0040] The metal nanowires 140 may be arranged randomly such that the orientation of each individual nanowire is random. This random arrangement may form a network of overlapping metal nanowires 140 on the curable resm coating 130. The contact between the nanowires impro ves the overall conductivity of the metal nanowire network. There may also be gaps or spaces between the metal nanowires 140.

[0041] The metal nanowires 140 may have varying aspect ratios. Ideally, the metal nanowires 140 are sized to provide the desired electrical properties, such as conductivity. The deposited layer of metal nanowires 40 formed on the curable resm coating may be at least 2 microns, at least 5 microns, at least 10 microns. The deposited layer of metal nanowires 140 formed on the curable resin coating 130 may range from 10 nm to 500 nm. In general, adjusting the concentration of the metal nano wires 140 and/or the amount of the solution containing the metal nanowires 140 may increase or decrease the conductivity achieved.

[00421 The metal nanowires 140 may be deposited on the curable resin coating 130 as shown in FIG. 2B. A solution containing the metal nanowires 140 may be initially prepared. The solution may be applied to the curable resin coating 130 using suitable solution-coating methods known in the art. The solution may include the metal nanowires 140 and an aqueous solvent. The aqueous solvent may include alcohol and/or other organic solvents. The solution may further include a polymer binder. The polymeric binder may be a curable resin similar to the

composition of the curable resin coating 130. For example, suitable polymeric binders may include polyurethane, acrylic resin, acrylic copolymers, polyethers, polyesters, epoxy containing polymers, and mixtures thereof.

[0043] In o e aspect of the disclosure, the solution may include 0.001 wt% to 5 wt% metal nanowires 140. In another aspect, of the disclosure, the solution may include 0.005 wt% to 2 wt% metal nanowires 1 0. Other concentrations of metal nanowires 140, however, are also contemplated.

[0044] In one aspect, the metal nanowires 140 may be applied to the curable resin coating 130 using a roll-to-roll method. The metal nanowires 140 may also be deposited on the curable resin coating 130 by a spray coating method and dried. The spray coatmg method may be performed at room temperature and at atmospheric pressure.

[0045] In some aspects of the present disclosure, the metal nanowires 140 are embedded into the curable resin coating 130. The curable resin coatmg 130 may be heated until the resin composition softens or melts to receive one or more metal nanowires 140. In one aspect, the embedding step involves heating the substrate 1 10 to a temperature sufficient to soften or melt the curable resin coatmg 130. The substrate 1 10 may be heated, for example, to a temperature that is equal to or slightly above the glass transition temperature of the curable resin composition. Suitable mechanical methods may also be used to embed the metal nanowires 140, if needed. For example, the metal nanowires 140 may be embedded into the curable resin coating 130 by- applying pressure.

[0046] In one aspect of the present disclosure, a polyethene terephthalate substrate 1 10 is heated to 100 degrees Celsius f°C) or higher which is the glass transition temperature of the curable resin coating 130 so that metal nanowires 140 permeate into the softened curable resm coating 130. The surface roughness of the metal nanowires 140 has also significantly decreased because the metal nanowires 140 are now embedded in the curable resin coating 130.

[00471 After the metal nanowires 140 are embedded into the curable resm coating 130, a patterning mask 160 is applied over the curable resin coating 130. As shown in FIG. 2D, the patterning mask 160 may be positioned a distance above the curable resin coating 130, which now contains embedded metal nanowire 140. The patterning mask 160 may also be adhered to the curable resin coating 130. However, it may be preferable to position the patterning mask 160 above the curable resm coating 130 to avoid introducing any surface defects to the curable resin coating 130.

10048] According to one aspect of the present disclosure, the patterned film mask 160 includes a base layer 162 and a plurality of through holes 165 permeating through the base layer 162. The film mask 160 includes a plurality of through holes 165 through which light passes to form the transparent conductive layer 120. The through holes 165 should permeate from one surface of the base layer 162 to the opposing surface of the base layer 162. For example, the through holes 65 permeate from the bottom surface of the base layer 62 to the top surface of the base layer 162. In one aspect of the disclosure, the through holes 165 are formed by a laser scribing process or a punching process. Other processes, however, are contemplated by the present disclosure.

[0049] The through holes 165 in the base layer 162 correspond to the desired pattern for the transparent conductive layer 120. The number of through holes 165 and the dimensions of the through holes 165 are a design choice and represent the desired features for the patterned conductive film 100 or the electrode. In some aspects of the present disclosure, the through holes 165 may have different shapes and sizes from each other within the same mask 160. In some aspects, the through holes 165 may be circular perforations in the base layer 162. In other aspects, the through holes 165 are formed in the shape of a rectangle. According to other aspects of the disclosure, the through holes 165 may have shapes that are neither circular nor rectangular.

[0050] One or more portions of the curable resin coating 130 may be masked or covered by the patterning mask 160. A portion(s) of the curable resm coating 130 will also remain unmasked or uncovered by the patterning mask 160.

[0051] Next, a light source 170 emits radiation on the patterning mask 160 while the mask 160 is positioned over the curable resin coating 130. The portions of the curable resin coating 130 that remain unmasked will be exposed to the light source 170 as shown in FIG. 2D. These unmasked portions of the curable resin coating 130 may cure i.e., cross-link, upon exposure to the light source 170. in one aspect, the light source 170 may emit ultraviolet light. Any light source 170, however, may be suitable provided that the unmasked portions of the curable resm coating 130 cure upon exposure.

[0052 J The curing step is a key feature of the process because the portions of the resin coating 130 that become cured form the desired pattern for the patterned conductive film 100. The masked portions of the curable resin coating 130 will remain uncured upon exposure to the light source 170. FIG. 2.E shows the curable resin coating having cured portions 130A and uncured portions 130B.

[0053] After curing, the uncured portions 130B of the curable resin coating 130, including the embedded metal nanowires 140 may be removed to expose regions of the substrate 110. FIG 2F shows the transparent conductive layer 120 with only the cured portions 13 OA. As shown, the transparent conductive layer 120 has raised pattern features that consist of the cured portions 130A and the metal nanowires 140.

[0054] The removal of the uncured portions may occur by applying a solvent, such as water. The solvent chosen for this removal step depends largely on the composition of the curable resin coating 130 and the metal nanowires 140, In one aspect of the disclosure, the solvent may dissolve the uncured portions of the resin coating 130 while leaving the cured portions intact. In some aspects, the solvent to remove the uncured resin coatmg 130 portion may be acetone, isopropanol (IPA), N-rnethylpyrrolidone (NMP), dimethyl sulfoxide (DM80), a combination thereof, or any organic solvent suitable to remove the uncured resm coating 130.

[0055] A protective film layer 1 50 may be applied after the curing step. The protective film layer 150 may be applied on top of the cured and uncured portions of the curable resin coating 130. The protective film layer 150 may also be applied to the substrate 1 10 opposite the transparent conductive layer 120. These protective film layers 150 may be removed by a solvent such as water or a suitable organic solvent. According to one aspect of the disclosure, the patterned conductive film 100 includes a protective film layer 150 above the patterned transparent conductive layer 120. A solvent may be applied to remove the protective film layer 150 and the uncured portions 130B of the curable resin coatmg 130. One of the advantages of the disclosed process is that the patterning can be achieved by simplified photolithography because the curable resin coating 130 includes an ultraviolet sensitive polymer. Therefore, a patterned transparent conductive electrode using silver nanowire having improved surface roughness is easily fabricated and suitable for applying OLED device.

[0056] It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.

Definitions

[0057] 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.

[0058] 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.

[0059] As used herein, the term "combination" is inclusive of blends, mixtures, alloys, reaction products, and the like.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] As used herein, the term "light" means electromagnetic radiation including ultraviolet, visible or infrared radiation.

[0064] As used herein, the term "photopolymer" refers to a polymeric composition that undergoes polymerization, cross-linking, any hardening or curing reactions or otherwise undergoes structural and property changes upon exposure to light.

[0065] As used herein, the term "photoinitiator" refers to a composition that generates a reactive species such as free radicals, cations, ions, when exposed to radiation (UV or visible).

[0066] As used herein, the term "transparent" 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.

[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 1. A process for fabricating a patterned conductive film on a substrate, the process comprising: (a) forming a curable resin coating on the substrate; (b) depositing a plurality of metal nanowires on the curable resin coating; (c) embedding one or more of the plurality of metal nanowires in the curable resin coating; (d) applying a patterning mask over the curable resin coating wherein one or more portions of the curable resin coating are exposed and one or more portions of the curable resin coating are masked; and (e) curing the one or more exposed portions of the curable resin coating to form the patterned conductive film.

[0070] Aspect 2. The process of aspect 1 , further comprising removing the patterning mask after curing the one or more exposed portions of the curable resin coating. [0071] Aspect 3. The process of aspects 1 or 2, further comprising removing the uncured portions of the curable resin coating after curing the one or more exposed portions of the curable resin coating.

[0072] Aspect 4. The process of aspect 3, wherein removing the uncured portions of the curable resin coating includes applying one or more solvents to the uncured portions of the curable resin coating.

[0073] Aspect 5. The process of aspect 4, wherein the one or more solvents includes an organic solvent.

[0074] Aspect 6. The process of any one of the preceding aspects, further comprising applying a protective film layer over the patterned conductive film, wherein the patterned conductive film includes uncured portions of the curable resin coating.

[0075] Aspect 7. The process of aspect 6, wherein the protective film layer comprises polyethylene.

[0076] Aspect 8. The process of any one of the preceding aspects, further comprising applying a protective film layer on the surface of the substrate opposite the patterned conductive film.

[0077] Aspect 9. The process of any one of the preceding aspects, further comprising applying a protective film layer on the surface of the substrate opposite the patterned conductive film, wherein the protective film layer comprises polyethylene terephthalate.

[0078] Aspect 10. The process of any one of the preceding aspects, wherein the curing includes applying light to the exposed portions of the curable resin coating.

[0079] Aspect 11. The process of any one of the preceding aspects, wherein the curing includes applying ultraviolet light to the exposed portions of the curable resin coating.

[0080] Aspect 12. The process of any one of the preceding aspects, wherein the substrate is polymeric.

[0081] Aspect 13. The process of any one of the preceding aspects, wherein the substrate comprises at least one of the group consisting of: polyethylene terephthalate, poly

methylacrylate, polymethyl methacrylate, polyacrylate copolymer, polyurethane, polyurethane copolymer, cellulose acetate, polystyrene, polystyrene copolymer, polyimide and mixtures thereof.

[0082] Aspect 14. The process of any one of the preceding aspects, wherein the substrate comprises polyethylene terephthalate. [0083] Aspect 15. The process of any one of the preceding aspects, wherein the substrate is flexible.

[0084] Aspect 16. The process of any one of the preceding aspects, wherein the substrate is a transparent.

[0085] Aspect 17. The process of any one of the preceding aspects, wherein the substrate is an electrode.

[0086] Aspect 18. The process of any one of the preceding aspects, wherein the forming the curable resin coating on the substrate includes (a) preparing a curable resin composition and (b) applying the curable resin composition to the substrate.

[0087] Aspect 19. The process of aspect 18, wherein the applying the curable resin coating to the substrate includes at least one of spraying, dipping, roll-coating or roll-to-roll coating the curable resin material onto the surface of the substrate.

[0088] Aspect 20. The process of aspect 19, wherein the applying the curable resin coating to the substrate includes roll-to-roll-coating the curable resin material onto the surface of the substrate.

[0089] Aspect 21. The process of any one of the preceding aspects, the depositing the plurality of metal nanowires on the curable resin coating includes roll-to-roll-coating the metal nanowires on the curable resin coating.

[0090] Aspect 22. The process of any one of the preceding aspects, wherein the embedding the metal nanowires in the curable resin coating includes softening or melting the curable resin coating.

[0091] Aspect 23. The process of aspect 22, wherein the softening or melting the curable resin coating includes heating the substrate.

[0092] Aspect 24. The process of aspect 23, wherein the heating the substrate includes heating to a temperature that is equal to or greater than the glass transition temperature of the curable resin coating.

[0093] Aspect 25. The process of aspect 24, wherein the temperature is at least 100 degrees Celsius.

[0094] Aspect 26. The process of any one of the preceding aspects, wherein the embedding the metal nanowires in the curable resin coating further includes applying pressure to metal nanowire deposited curable resin coating. [0095] Aspect 27. The process of any one of the preceding aspects, wherein the plurality of metal nanowires comprises at least one of silver, gold or copper.

[0096] Aspect 28. The process of aspect 27, wherein the plurality of metal nanowires comprises silver.

[0097] Aspect 29. The process of any one of the preceding aspects, wherein the curable resin coating comprises a photopolymer.

[0098] Aspect 30. The process of aspect 29, wherein the photopolymer comprises an ultraviolet sensitive photopolymer.

[0099] Aspect 31. The process of aspect 29, wherein the curable resin composition comprises a photopolymer having one or more diazo-functional groups.

[00100] Aspect 32. The process of aspect 29, wherein the curable resin composition comprises a photopolymer having one or more styryl functional groups.

[00101] Aspect 33. The process of aspect 29, wherein the photopolymer comprises styryl pyridinium or a styryl pyridinium derivative.

[00102] Aspect 34. The process of aspect 29, wherein the photopolymer comprises a polyvinyl alcohol based polymer and styryl pyridinium or a styryl pyridinium derivative.

[00103] Aspect 35. The process of aspect 29, wherein the curable resin coating comprises poly(vinyl pyridine).

[00104] Aspect 36. The process of aspect 29, wherein the photopolymer is capable of absorbing light in a wavelength in the range from 180 nm to 500 nm.

[00105] Aspect 37. The process of aspect 36, wherein the photopolymer is capable of absorbing light in a wavelength in the range from 320 nm to 400 nm.

[00106] Aspect 38. The process of aspects 1-28, wherein the curable resin coating comprises a polymer binder and a photoinitiator.

[00107] Aspect 39. The process of aspect 38, wherein the polymer binder is selected from the group consisting of: polyester acrylate, epoxy acrylate, urethane acrylate, and silicone resin acrylate.

[00108] Aspect 40. An OLED comprising the transparent conductive film prepared by the process of aspect 1.

[00109] Aspect 41. The process of any of the preceding aspects, wherein the patterned conductive film has total visible light transmission greater than 85%. [00110] Aspect 42. The process of aspect 41, wherein the patterned conductive film has total visible light transmission greater than 90%.

[00111] Aspect 43. The process of any of the preceding aspects, wherein the transparent conductive film has an ASTM D1003 haze value less than or equal to 1.5%, or less than or equal to 0.8%.

[00112] Aspect 44. The process of any of the preceding aspects, wherein the patterned conductive film is at least 50 um thick.

[00113] Aspect 45. The process of any one of the preceding aspects, wherein the patterned conductive film has an electrical resistance of about 45-55 ohms.

[00114] Aspect 46. A process for fabricating a patterned conductive film on a substrate, the process comprising: (a) forming a curable resin coating on the substrate, wherein the curable resin coating comprises an ultraviolet sensitive photopolymer; (b) depositing a plurality of silver nanowires on the curable resin coating; (c) heating the substrate to soften or melt the curable resin coating, wherein one or more of the plurality of silver nanowires become embedded in the curable resin coating; (d) applying a patterning mask over the curable resin coating, wherein one or more portions of the curable resin coating are exposed and one or more portions of the curable resin coating are masked; (e) applying ultraviolet light to cure the one or more exposed portions of the curable resin coating; (f) removing the patterning mask; and (g) applying one or more solvents to remove the uncured portions of the curable resin coating.

[00115] Aspect 47. The process of aspect 46, wherein the substrate comprises at least one of the group consisting of: polyethylene terephthalate, poly methylacrylate, polymethyl methacrylate, polyacrylate copolymer, polyurethane, polyurethane copolymer, cellulose acetate, polystyrene, polystyrene copolymer, polyimide and mixtures thereof.

[00116] Aspect 48. The process of any of aspects 46-47, wherein the patterned conductive film and the substrate are transparent.

[00117] Aspect 49. The process of any of aspects 46-48, wherein the forming the curable resin coating on the substrate includes roll-to-roll coating a curable resin material onto the surface of the substrate.

[00118] Aspect 50. The process of any of aspects 46-49, wherein the depositing the plurality of silver nanowires on the curable resin coating includes roll-to-roll-coating the silver nanowires on the curable resin coating. [00119] Aspect 51. The process of any of aspects 46-50, wherein the heating the substrate includes heating to a temperature that is equal to or greater than the glass transition temperature of the curable resin coating.

[00120] Aspect 52. The process of any of aspects 46-51, wherein the curable resin coating comprises an ultraviolet sensitive photopolymer.

[00121] Aspect 53. The process of aspect 52, wherein the curable resin composition comprises a photopolymer having one or more diazo-functional groups, or one or more styryl functional groups.

[00122] Aspect 54. The process of any of aspects 46-53, wherein the photopolymer comprises styryl pyridinium or a styryl pyridinium derivative.

[00123] Aspect 55. The process of any of aspects 46-54, wherein the photopolymer comprises a polyvinyl alcohol based polymer and styryl pyridinium or a styryl pyridinium derivative.

[00124] Aspect 56. The process of any of aspects 46-55, wherein the curable resin coating comprises poly(vinyl pyridine).

[00125] Aspect 57. The process of any of aspects 46-56, wherein the curable resin coating comprises a polymer binder and a photoinitiator.

[00126] Aspect 58. The process of aspect 57, wherein the polymer binder is selected from the group consisting of: polyester acrylate, epoxy acrylate, urethane acrylate, and silicone resin acrylate.

[00127] Aspect 59. The process of any of aspects 46-58, wherein the patterned conductive film has at least one of: (a) total visible light transmission greater than 90%; (b) an ASTM D1003 haze value less than or equal to 0.8%; and (c) an electrical resistance of about 45-55 ohms.

[00128] Aspect 60. The process of any of aspects 46-58, wherein the patterned conductive film has at least one of: (a) total visible light transmission greater than about 88%; (b) an ASTM D1003 haze value less than or equal to 1.5%; and (c) an electrical resistance of about 15-20 ohms.

[00129] Aspect 61. The process of any of the previous aspects, wherein the film exhibits substantially no change in surface hardness, adhesion, yellowing index, transmittance or haze after exposure to air having a relative humidity of 85% and a temperature of 85 °C for 240 hours. [00130] Aspect 62. The process of any of the previous aspects, wherein the film exhibits less than or equal to a 10% change in reflectance after exposure to air having a relative humidity of 85% and a temperature of 85 °C for 240 hours.

EXAMPLES

[00131] 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. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric. Unless indicated otherwise, percentages referring to composition are in terms of wt%.

[00132] 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.

Example 1

[00133] A silver nanowire (AgNW) film was formed according to methods described herein and various properties of the film were tested before and after exposure to harsh environmental conditions. The purpose of the exposure was to evaluate the reliability of the film. The environmental conditions included exposure to air at 85% relative humidity (RH) and 85 degrees Celsius (°C) for 240 hours. Results of the test are provided in Table 1 :

Table 1. ] Reliability of Ag W Film

Change in Transmittance Yellowing Adhesion Surface Reflectance (AR) Index Hardness

Before exposure N/A 78.6 5.5 5B <6B

After exposure 1.1 78.9 5.5 5B <6B (85% RH, 85 °C,

240 hours) [00134] As is evident from the data, the film had comparable properties after exposure as it did prior to exposure, with identical surface hardness, adhesion and yellowing index and almost identical transmittance. Reflectance was within 10% of its pre-exposure value.

Examples 2, 3

[00135] A silver nanowire (AgNW) film was formed on a polycarbonate (PC) substrate (Example 2) and on a polyethylene terephthalate (PET) substrate (Example 3) according to methods described herein and transmittance and haze of each film were tested before and after exposure to harsh environmental conditions. The purpose of the exposure was to evaluate the reliability of the film. The environmental conditions included exposure to air at 85% relative humidity (RH) and 85 degrees Celsius (°C) for 240 hours. Results of the test are provided in Table 2:

Table 2. Reliability of AgNW Film

[00136] As is evident from the data, each of the films had comparable properties after exposure as they did prior to exposure, with the AgNW film on the PC substrate (Example 2) having an identical transmittance after exposure and a haze within about 5% of its pre-exposure value, and the AgNW film on the PET substrate having an identical haze and a substantially identical (within 1%) transmittance after exposure.

[00137] 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 non-volatile 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.

[00138] 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 invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

CLAIMS We claim:

1. A process for fabricating a patterned conductive film on a substrate, the process comprising:

(a) forming a curable resin coating on the substrate;

(b) depositing a plurality of metal nanowires on the curable resin coating;

(c) embedding one or more of the plurality of metal nanowires in the curable resin coating;

(d) applying a patterning mask over the curable resin coating wherein one or more portions of the curable resin coating are exposed and one or more portions of the curable resin coating are masked; and

(e) curing the one or more exposed portions of the curable resin coating to form the patterned conductive film.

2. The process of claim 1, further comprising applying one or more solvents to uncured portions of the curable resin coating to remove the uncured portions of the curable resin coating after curing the one or more exposed portions of the curable resin coating.

3. The process of any one of the preceding claims, wherein the curing includes applying ultraviolet light to the exposed portions of the curable resin coating.

4. The process of any one of the preceding claims, wherein the substrate comprises at least one of the group consisting of: polyethylene terephthalate, poly methylacrylate, polymethyl methacrylate, polyacrylate copolymer, polyurethane, polyurethane copolymer, cellulose acetate, polystyrene, polystyrene copolymer, polyimide and mixtures thereof.

5. The process of any one of the preceding claims, wherein the substrate is transparent.

6. The process of any one of the preceding claims, wherein the forming a curable resin coating on the substrate includes (a) preparing a curable resin composition and (b) applying the curable resin composition to the substrate by at least one of spraying, dipping, roll-coating or roll-to-roll coating the curable resin coating onto a surface of the substrate.

7. The process of any one of the preceding claims, the depositing the plurality of metal nanowires on the curable resin coating includes roll-to-roll-coating the metal nanowires on the curable resin coating.

8. The process of any one of the preceding claims, wherein the embedding the metal nanowires in the curable resin coating includes heating the substrate to soften or melt the curable resin coating.

9. The process of claim 8, wherein the heating the substrate includes heating to a temperature that is equal to or greater than a glass transition temperature of the curable resin coating.

10. The process of any one of the preceding claims, wherein the plurality of metal nanowires comprises at least one of silver, gold or copper.

11. The process of claim 10, wherein the plurality of metal nanowires comprises silver.

12. The process of any one of the preceding claims, wherein the curable resin composition comprises an ultraviolet sensitive photopolymer.

13. The process of any one of the preceding claims, wherein the curable resin composition comprises a photopolymer having one or more diazo-functional groups or one or more styryl functional groups.

14. The process of any one of the preceding claims, wherein the photopolymer comprises styryl pyridinium or a styryl pyridinium derivative.

15. The process of any one of the preceding claims, wherein the photopolymer comprises a polyvinyl alcohol based polymer and styryl pyridinium or a styryl pyridinium derivative.

16. The process of any one of the preceding claims, wherein the curable resin coating comprises poly(vinyl pyridine).

17. The process of any one of claims 1-11, wherein the curable resin coating comprises a polymer binder and a photoinitiator and the polymer binder is selected from the group consisting of: polyester acrylate, epoxy acrylate, urethane acrylate, and silicone resin acrylate.

18. The process of any one of the preceding claims, wherein the film exhibits substantially no change in surface hardness, adhesion, yellowing index, transmittance or haze after exposure to air having a relative humidity of 85% and a temperature of 85 °C for 240 hours.

19. An OLED comprising the patterned conductive film prepared by the process of any one of the preceding claims.

20. A process for fabricating a patterned conductive film on a substrate, the process comprising:

(a) forming a curable resin coating on the substrate, wherein the curable resin coating comprises an ultraviolet sensitive photopolymer;

(b) depositing a plurality of silver nanowires on the curable resin coating;

(c) heating the substrate to soften or melt the curable resin coating, wherein one or more of the plurality of silver nanowires become embedded in the curable resin coating;

(d) applying a patterning mask over the curable resin coating, wherein one or more portions of the curable resin coating are exposed and one or more portions of the curable resin coating are masked;

(e) applying ultraviolet light to cure the one or more exposed portions of the curable resin coating;

(f) removing the patterning mask; and (g) applying one or more solvents to remove uncured portions of the curable resin coating.