Formulation for preparing an optical metal oxide layer

Abstract

The present invention relates to a formulation for preparing an optical metal oxide layer.

Description

[Technical Field]

[0001] The present invention relates to formulations for preparing an optical metal oxide layer comprising one or more metavanadates, the use of the formulations, a method for preparing an optical metal oxide layer, and an optical device comprising an optical metal oxide layer. The formulations and methods according to the present invention are particularly suitable for preparing metal oxide optical layers for optical applications or devices, such as diffraction gratings for augmented reality (AR) and / or virtual reality (VR) devices. The metal oxide layer exhibits desirable optical properties such as (a) a high refractive index (RI) of >1.6, preferably >2.0, at wavelengths ≤520 nm, and / or low absorption of <0.5% at 480 nm, and / or low degree of haze formation; (b) desirable mechanical properties such as low shrinkage; (c) desirable coating properties such as a dense layer and a flat surface structure; and / or (d) desirable filling properties such as uniform filling of topographic features on a patterned substrate.

[0002] Embodiments of the present invention make it possible to prepare optical metal oxide layers on the surfaces of both patterned and unpatterned substrates. The metal oxide layer can form various structures, such as a layer covering the surface of an unpatterned substrate and / or a filler covering topographic features such as gaps on the surface of a patterned substrate, thereby providing a high-refractive-index optical structure. In particular, embodiments of the present invention enable the preparation of advanced optical gap filling with less overburden by avoiding typical problems that occur when layer deposition or gap filling is performed by physical vapor deposition (PVD) or chemical vapor deposition (CVD) techniques, such as incomplete or excessive gap filling due to undesirable deposition and layer growth characteristics, including reduced or increased deposition or growth rates at corners and edges, thereby enabling easy and cost-effective mass production of complex optical devices.

[0003] Embodiments of the present invention are particularly suitable for preparing optical metal oxide layers having a high refractive index for optical devices such as diffraction gratings in AR and / or VR devices.

[0004] Finally, the present invention provides an optical device, preferably an AR and / or VR device, comprising an optical metal oxide layer, which can be obtained by the method according to the present invention or prepared by using the formulation according to the present invention. [Background technology]

[0005] Vanadium pentoxide (V2O5) has a refractive index of n=2.8. Despite this, vanadyl compounds have only been slightly investigated as high-refractive-index materials due to their strong absorption in the visible region, which produces a strong red or orange color. In most cases, vanadium in vanadyl compounds adopts one of two coordination structures. Octahedral coordination is dominant in most polyoxometalate compounds and vanadium pentoxide, resulting in the red coloration of vanadyl compounds and making these compounds unattractive for transparent applications.

[0006] State-of-the-art optical devices typically include an optical grating fabricated from a composite material with a substrate as a support and a complex, intricate pattern on it, where the pattern consists of different layers or stacks of layers. Generating such complex and intricate patterns usually requires a structuring process, which becomes increasingly difficult as the size of the structure being prepared decreases.

[0007] Diffraction gratings are a core component of so-called XR devices (primarily XR glasses), in addition to having a wide range of viable applications in various application fields such as spectrometers or optical storage systems (CDs, DVDs, etc.). In this context, R stands for reality, and X indicates different attributes such as virtual, augmented, or mixed reality. Therefore, diffraction gratings form part of the core of the so-called optical engine in XR devices, particularly in augmented and mixed reality glasses. When virtual reality glasses are built as head-mounted displays, they often consist of conventional liquid crystal (LC) organic light-emitting diode (OLED) displays built into the device and therefore do not necessarily require a diffraction grating. In contrast, augmented and mixed reality glasses are designed in a way that allows consumers to obtain a visual impression of their environment in the best possible condition, as if they were not wearing glasses at all. However, they also enable the provision and delivery of digital information and its projection into the individual's field of view. Additional digital information is collected by recognizing and analyzing the environment that the individual is currently observing or viewing. To transmit and project assisted digital information to an individual's eyes, augmented reality or mixed reality glasses are equipped with an information supply unit coupled to an optical waveguide system, through which optically encoded assisted information is transmitted directly to the lenses of the glasses. Here, the information passes through a diffraction grating, which couples the incident light to the lens, splitting the incident light according to its angular information and spectral band by diffraction. After the light is input coupled, the lens functions as a waveguide, enabling the light to be transmitted to and into the individual's pupil. The position of the input coupling of the light is independent of any preferred position and therefore irrelevant to what the technical needs imply. The transverse direction of the light within the lens is determined by the diffraction grating that diffracts or splits the light. At specific positions in the lens, second and third diffraction gratings function to change the transverse direction of the light, thereby performing the projection of light into the user's pupil. The transverse direction of the light within the glasses is achieved by internal total internal reflection (TIR) ​​of the light, and thus by bouncing multiple times between the glass interfaces until it reaches another diffraction grating, thereby changing the internal TIR direction of the light (see Figure 2).The second and third diffraction gratings are shaped and positioned in a different direction with respect to the first and input coupling diffraction gratings, for example, by a specific angular deformation of the longitudinal axis, thereby making it possible to change the propagation direction of the total internal reflection light. Needless to say, the lens itself or the material from which the lens is made shall be non-absorbing. Otherwise, the assist information will not reach the user's pupil or will only reach in a state where the light intensity is significantly attenuated. This process functions regardless of whether a reflective diffraction grating or a transmissive diffraction grating is used. Usually, the lens has both types of diffraction gratings to properly guide light. Although there are differences in the optical performance between the reflective diffraction grating and the transmissive diffraction grating, it should also be mentioned that this is not of further interest in the context of the present invention. The basic structure of the diffraction gratings is very similar, which is more important in this regard.

[0008] Nevertheless, different designs and structures exist to realize the waveguide, such as surface relief (SR) diffraction gratings or volume phase holographic (VPH) diffraction gratings. Both types have a very similar appearance. In the simplest case, a diffraction grating is attached in some form on the surface of the waveguide material (here the lens). The diffraction grating itself consists of an array of microstructures, mainly trenches of a first material type having a refractive index RI 01, but is not limited thereto. The geometric shape of the trenches can be very diverse, ranging from rectangular to V-shaped trenches, U-shaped, etc. The width (including structures with different widths), the geometric shape of the trenches, their pitch, and their depth (including different depths) are specifically designed to affect the diffraction pattern of the incident light to be diffracted.

[0009] In the case of an SR diffraction grating (SRG), a trench or structure of a first material type (material 01) having a refractive index (RI 01) is filled with a second material type (material 02) having a refractive index (RI 02), where RI 02 is sequentially different from RI 01 (see Figures 1 and 3). For completeness, it should be noted that material 01 or material 02 may consist of a stack of structured layers, each comprising different material compositions with different refractive indices, stacked on top of each other, thereby forming material 01 or material 02 having effective or stepped refractive indices RI 01 or RI 02, respectively. Incidentally, the (effective or stepped) refractive indices RI 01 and RI 02 depend on the refractive index of the waveguide or lens from which the glass is fabricated. When using a glass lens with a high refractive index (n03 > 1.46), the (effective or stepped) refractive indices of material 01 and material 02 are considered to be higher than the refractive index of the lens itself, thereby achieving and exceeding an RI value of 2.0. High-performance diffraction gratings, particularly SR-type diffraction gratings, can be manufactured using standard lithography and deposition techniques known through microfabrication processes such as those used in the manufacture of integrated circuits.

[0010] Such standard techniques typically include physical vapor deposition (PVD) or chemical vapor deposition (CVD) processes, and often suffer from incomplete gap filling due to undesirable deposition and / or layer growth characteristics, including increased deposition and / or growth rates at corners and edges. Such incomplete gap filling results in the formation of voids within structures filled with PVD and CVD materials. In addition to void formation, the surface of the substrate is covered by a PVD layer and / or CVD layer having a thickness approximately the same as the maximum depth of the deepest structure filled by the deposited gap filling material (see FIGS. 4 and 5). However, in some applications, it may be necessary to expose the surface of the substrate so that it can be used for further processing. As a result, an undesirable overburden layer due to PVD or CVD needs to be removed, for example, by chemical mechanical polishing (CMP), without damaging the underlying original substrate surface. CMP is well established in the process of manufacturing integrated circuits, but CMP is a time-consuming and costly process and may be considered a potential economic drawback for high-volume production of state-of-the-art optical devices, particularly diffraction gratings. Therefore, it is desirable to have a solution for the advanced and cost-effective manufacture of optical gratings that does not require CMP for gap filling (see FIG. 6).

[0011] The present invention addresses various problems associated with techniques for preparing optical gratings for state-of-the-art optical devices as described above. Here, the focus is on improved optical properties, improved mechanical properties, improved coating properties, and improved filling properties. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0012] The object of the present invention is to provide formulations and methods for preparing an optical metal oxide layer, the metal oxide layer being particularly suitable for optical applications and can be used, for example, in optical devices such as diffraction gratings for AR and / or VR devices. The resulting optical metal oxide layer exhibits desirable optical properties such as (a) a high refractive index (RI) of >1.6, preferably >2.0, at wavelengths ≤520 nm, low absorption, and low degree of haze formation; (b) desirable mechanical properties such as low shrinkage; (c) desirable coating properties such as a dense layer and a flat surface structure; and (d) desirable filling properties such as uniform filling of topographic features on a patterned substrate.

[0013] Furthermore, an object of the present invention is to provide formulations and methods that enable the easy and cost-effective preparation of optical metal oxide layers.

[0014] A further object of the present invention is to enable the preparation of optical metal oxide layers on the surface of patterned or unpatterned substrates. The metal oxide layer can form various structures, such as a layer covering the surface of an unpatterned substrate and / or a filler covering topographic features such as gaps on the surface of a patterned substrate, thereby providing a high refractive index optical structure.

[0015] Therefore, an object of the present invention is to provide formulations and methods for preparing optical metal oxide layers, which enable the preparation of advanced optical gap fillers with less overbaden, thereby enabling easy and cost-effective mass production of complex optical devices.

[0016] A further object of the present invention is to provide a method for preparing an optical metal oxide layer that avoids typical problems that occur when layer deposition or gap filling is performed by PVD or CVD technology, such as incomplete or excessive gap filling due to undesirable deposition and layer growth characteristics, including a decrease or increase in deposition or growth rate at corners and edges.

[0017] An object of the present invention is that metal complexes and formulations are particularly suitable for preparing metal oxide optical layers having a high refractive index and low absorption (low optical loss) simultaneously for optical devices such as diffraction gratings in AR and / or VR devices.

[0018] Finally, an object of the present invention is to provide an optical device, preferably an AR and / or VR device, comprising an optical metal oxide layer that can be obtained by the method according to the present invention or prepared by using the formulation according to the present invention, thereby exhibiting the beneficial effects described above. [Means for solving the problem]

[0019] To our surprise, the inventors have found that the above objectives can be achieved individually or in any combination by formulations for preparing optical metal oxide layers as defined in the claims. That is, the formulations include at least: (i) an oligomer of a metavanadate salt, preferably the oligomer is an oligomer of the same metavanadate salt or an oligomer of a mixture of metavanadates, preferably the oligomer is of formula (I) [ka] (In the formula, X represents a cation, m is 1, 2, or 3, preferably 1 or 2. n is an integer greater than or equal to 2, preferably between 2 and 10 in water. Oligomers represented by; and (ii) formulation vehicle; Includes.

[0020] In addition, a method for preparing an optical metal oxide layer is provided, comprising the following steps (a) to (c): (a) A step of providing a compound, wherein the compound is (i) One or more metavanadates according to formula (I) (wherein X represents a cation, m is 1, 2, or 3, and n is an integer of 2 or more, preferably 2 to 10 in water); and (ii) One or more compound media Processes including; (b) A step of applying the compound onto the surface of the substrate; (c) A step of converting the compound on the surface of the substrate into an optical metal oxide layer. Includes.

[0021] Furthermore, an optical device is provided that includes an optical metal oxide layer, which can be obtained or is obtainable by the preparation method described above.

[0022] The present invention further relates to the use of the above-mentioned formulations for forming an optical metal oxide layer.

[0023] Preferred embodiments of the present invention are described below in this specification and dependent claims. [Brief explanation of the drawing]

[0024] [Figure 1] A schematic cross-sectional view of an SR diffraction grating containing materials 01 and 02, where the refractive index IR 01 of material 01 is sequentially different from the refractive index IR 02 of material 02. [Figure 2] A schematic cross-sectional view of an SR diffraction grating (transmission type) that enables optical diffraction, including the propagation of light diffracted within a waveguide (e.g., a lens) due to total internal reflection. [Figure 3] A schematic cross-sectional view of an SR diffraction grating that provides a gap (trench) filled with a high refractive index material (material 02), where the refractive index of material 02 is successively different from the refractive index of material 01 located on the side of the gap (trench). [Figure 4] A schematic diagram illustrating a gap-filling process involving PVD or CVD, and the removal of undesirable overburden. [Figure 5] A schematic diagram of a gap-filling process involving PVD or CVD, where cavities are formed and remain within gaps and sedimentary layers. [Figure 6] A schematic diagram of a gap-filling process using a formulation containing the metal complex of the present invention or a formulation thereof converted to a metal oxide. [Figure 7] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 1 is shown. [Figure 8A] The image shows an SEM image of a coated silicon nitride substrate with trenches formed, illustrating the trench filling behavior, from Example 1. [Figure 8B] The image shows an SEM image of a coated silicon nitride substrate with trenches formed, illustrating the trench filling behavior, from Example 1. [Figure 9A] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 2 is shown. [Figure 9B] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 2 is shown. [Figure 10A] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 4 is shown. [Figure 10B] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 4 is shown. [Figure 11A] The image shows an SEM image of the coated silicon nitride substrate with trenches formed in Example 4, illustrating the trench filling behavior. [Figure 11B] The image shows an SEM image of the coated silicon nitride substrate with trenches formed in Example 4, illustrating the trench filling behavior. [Figure 12A] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 5 is shown. [Figure 12B] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 5 is shown. [Figure 13] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 6 is shown. [Figure 14A]The UV / Vis absorption spectrum of the coated fused silica substrate of Example 7 is shown. [Figure 14B] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 7 is shown. [Figure 15] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 8 is shown. [Figure 16A] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 9 is shown. [Figure 16B] The UV / Vis absorption spectrum of the coated fused silica substrate of Example 9 is shown. [Modes for carrying out the invention]

[0025] The present invention relates to a formulation for preparing an optical metal oxide layer containing one or more metavanadates, the use of the formulation, a method for preparing an optical metal oxide layer, and an optical device containing an optical metal oxide layer.

[0026] Surprisingly, the inventors have found that metavanadate salts can be used as optically transparent variable refractive index materials that can be processed from aqueous solutions to seamlessly fill trenches in SRG-type substrates.

[0027] Metabanadate is negatively charged [OV(O2)] - It is a one-dimensional (1D) chain structure consisting of repeating units of ]O. In aqueous solutions with a pH of 6 to 10, the 1D chain dissociates into shorter oligomers. At lower pH levels, the formation of octahedral-coordinated polyoxometalate structures is dominant, while in solutions with higher pH levels, the monomer ortho-vanadate form is formed.

[0028] While we do not wish to be constrained by theory, tetrahedral coordination in vanadium and metavanadate does not exhibit electron absorption in the visible spectral region. Dissolving metavanadate at a controlled pH yields short 1D chain oligomers that readily deposit on trenched substrates. Removal of the solvent induces condensation of the oligomer species, forming 1D chains identical to those in the substrate trenches. This adaptable dimensionality facilitates the efficient deposition and organization of metavanadate within the substrate trenches. Notably, their dimensionality indicates that the 1D metavanadate chains have a negligible tendency to form microcrystalline domains, thereby reducing undesirable light scattering at crystallite boundaries in the material film.

[0029] definition In relation to the present invention, the term “formulation medium,” or the plural term “formulation media,” as used herein, means one or more compounds that function as a solvent, suspending agent, carrier, and / or matrix for the complex and any other components contained in the formulation. The formulation medium is generally an inert compound that does not react with the complex and the other components. The formulation medium may be a liquid compound, a solid compound, or a mixture thereof. A preferred formulation medium contains water.

[0030] In this specification, when a range of numbers is indicated using "~", it includes both endpoints. For example, 1~10 means 1 or greater and 10 or less.

[0031] The term "variable refractive index material" refers to a material whose refractive index is 1.6 ≤ n ≤ 2.2.

[0032] As used herein, the term "surfactant" refers to an additive that reduces the surface tension of a given compound.

[0033] As used herein, the term "wetting dispersant" refers to an additive that enhances the spreading and penetrating properties of a given formulation. In this manner, it reduces the tendency of molecules to adhere to one another.

[0034] As used herein, the term "adhesion promoter" refers to an additive that increases the adhesion of a given formulation.

[0035] As used herein, the term "coordinating surfactant" refers to an additive that coordinates metal ions and acts as a surfactant.

[0036] As used herein, the term "viscosity improver" refers to an additive that increases the viscosity of a given formulation.

[0037] The term “optical device” as used herein refers to a device comprising one or more optical components for forming a light beam, including but not limited to diffraction gratings, lenses, prisms, mirrors, optical windows, filters, polarizing optical elements, UV and IR optical elements, and optical coatings. Preferred optical devices in connection with the present invention are augmented reality (AR) glasses and / or virtual reality (VR) glasses.

[0038] As used herein, the term "total amount of metavanadates" means the sum of all metavanadates contained in the formulation when two or more types of metavanadates are present.

[0039] When a value is given as a range, it should be understood that the endpoints are included in the range unless otherwise specified.

[0040] Preferred Embodiment Formulation for preparing an optical metal oxide layer In the first embodiment, a formulation for preparing an optical metal oxide layer is provided, the formulation comprising at least, (i) an oligomer of a metavanadate, preferably the oligomer is an oligomer of the same metavanadate or an oligomer of a mixture of metavanadates, preferably the oligomer is of formula I [ka] (In the formula, X represents a cation, m is 1, 2, or 3, preferably 1 or 2. n is an integer greater than or equal to 2, and optionally, n is between 2 and 10 if the formulation medium is water. Oligomers represented by; and (ii) formulation vehicle; Includes.

[0041] Here, [ka] teeth, [ka] It is equivalent to, In equation (I), "n-" is the [ka] This represents the sum of the negative charges.

[0042] Therefore, in other words, equation (I) is, [ka] It is equivalent to this.

[0043] Conveniently, the refractive index of metavanadate can be adjusted by changing the relative volume occupied by countercations without significantly affecting other physical properties. By introducing organic counterions, metavanadate can be made compatible with organic solvents, thereby extending the processability range of this class of material.

[0044] In an aqueous solution, metavanadate typically exists as an oligomer (n is 2 to 10, preferably 2 to 6), but exists as a polymer in the solid state.

[0045] In some embodiments, when they appear, cations X are each independently selected from the group consisting of ammonium cations, alkali metal cations, alkaline earth metal cations, and organic cations. In some embodiments, the cation is an ammonium cation. In some embodiments, the cation is, for example, K + , Li + or Na + and other alkali metal cations. In some embodiments, the cation is, for example, Ba 2+ , Ca 2+ , or Mg 2+ and other alkaline earth metal cations. In some embodiments, the cation is an organic cation such as, for example, a monovalent organic cation or a divalent organic cation. In some embodiments, the cation is NR1R2R3R4 + , wherein each of R1, R2, R3, and R4 is independently selected from H, C 1~18 alkyl, and C 1~18 alkyl alcohol. Preferred monovalent organic cations are, for example, protonated amines such as [N(C4H9)4] + , [H3N(C4H9)] + , [H3N(C4H8)NH3] 2+ , [N(CH3)3(C8H 17 )] + and phosphonium cations, and R1, R2, R3, and R4 are independently selected from C 1~18 alkyl and C 5~6 aryl. In some embodiments, the cation is PR1R2R3R4 + , and in each preferred embodiment, the cation is Li + , Na + , NH4 + , K + , Rb + , Cs + , [N(C4H9)4] +[PPh4] + [H3N(C4H9)] + [H3N(C4H8)NH3] 2+ , and [N(CH3)3(C8H 17 )] + Selected from the group consisting of . In a more preferred embodiment, the cation is Na + NH4 + , or an organic cation.

[0046] Conveniently, different metavanadates can be mixed to form a uniform film while fine-tuning the refractive index for the desired application. For example, the first and second metavanadates may be combined, in which case the first metavanadate results in a film with a lower refractive index compared to the film obtainable with a formulation containing the second metavanadate, and the film obtainable with a formulation containing the first and second salts results in a film with a refractive index that lies between the refractive indices obtainable with formulations containing the first and second metavanadates, respectively.

[0047] In some embodiments, the formulation comprises one or more metavanadates as defined above. In preferred embodiments, the formulation comprises a metavanadate as defined above. In other preferred embodiments, the formulation comprises two metavanadates. In other preferred embodiments, the formulation comprises three metavanadates. In even more preferred embodiments, the formulation comprises one or more metavanadates as defined above, each metavanadate selected from the group consisting of sodium metavanadate, potassium metavanadate, lithium metavanadate, and cesium metavanadate. In alternative preferred embodiments, one or more metavanadates comprises an organic cation, for example, tetrabutylammonium metavanadate and ammonium metavanadate. In one embodiment, the formulation comprises a mixture of organic metavanadates and inorganic metavanadates, and a formulation medium, optionally the formulation medium being a mixture of an organic solvent and water. In one embodiment, the formulation is a mixture of an organic solvent and water, with a ratio of 1:1, preferably 1.5:1. In another embodiment, the formulation is a mixture of PGME and water, with an optional ratio of approximately 1.5:1 between PGME and water.

[0048] In some embodiments, the weight ratio of the total amount of metavanadate in the formulation is in the range of 0.01 to 50% by weight, based on the total mass of the formulation. In preferred embodiments, the weight ratio of the total amount of metavanadate in the formulation is in the range of 0.1 to 30% by weight. In even more preferred embodiments, the weight ratio of the total amount of metavanadate in the formulation is in the range of 0.5 to 15% by weight.

[0049] In some embodiments, the formulation medium is a solution medium and / or a dispersion medium. In preferred embodiments, the formulation medium is selected from water, alcohols, carboxylic acids, ethers, ketones, amides, sulfones, and mixtures thereof. In even more preferred embodiments, the formulation medium is selected from a list consisting of propylene glycol methyl ether, di(propylene glycol) methyl ether, propylene glycol methyl ether acetate, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, propylene carbonate, propylene glycol, water, and mixtures thereof.

[0050] Typically, VO2 + It is the dominant species in most acidic solutions. At pH levels of approximately 3 to 6, the orange-colored decabanadate is dominant, depending on the total concentration. In the neutral pH range (sometimes called the "metabanadate" range), colorless mono-, di-, and cyclic oligobanadate species exist. For example, species H2VO4 - H2V2O7 2- V4O 12 4- V5O 15 5- (Often denoted as V1, V2, V4, and V5, respectively) each have a charge of -1 per vanadium atom, and in all cases, vanadium is tetrahedral-coordinated to oxygen. At pH levels above 8, linear tetramers (HV4O) are formed. 13 5- and V4O 13 6- ) The species is a single deprotonated dimer called HV2O7 3- It is formed together with [another element]. However, in alkaline solutions, the dominant species is the monoprotonated monomer HVO4. 2- , and its dimer V2O7 4- Therefore, at extremely alkaline pH levels (above 12), the only species present is the vanadate ion VO4. 3- That is the case.

[0051] Conveniently, the pH of aqueous formulations derived from vanadate is controlled so that the metavanadate form is dominant.

[0052] In some embodiments, the pH of the formulations described above is 6 to 11, preferably 7 to 9. Formulations with a pH below 6 produce a film that absorbs light in the violet to blue region of the visible spectrum, which may cause these films to appear red. Formulations with a pH above 11 may produce a microcrystalline film. Microcrystalline films may scatter light and may produce films with a relatively low refractive index of n < 1.47. Conveniently, the pH is measured using a pH meter.

[0053] In some embodiments, the formulation further comprises (iii) one or more additives. Each additive may be individually selected from the group consisting of wetting agents, dispersants, adhesion promoters, polymer matrices, and surfactants.

[0054] The presence of one or more additives in the formulation according to the present invention can improve the properties of the optical metal oxide layer obtained or obtainable by the formulation, such as the hardness of the material, shrinkage rate, refractive index, transmittance, absorbance, and suppression of haze.

[0055] Preferred surfactants are surfactants, preferably including surfactant metal oxides and / or surfactant organic compounds. Examples of surfactant organic compounds include nonionic surfactants, anionic surfactants, and amphoteric surfactants, which may be coordinating or non-coordinating.

[0056] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, such as polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, and 30-polyoxyethylene cetyl ether; polyoxyethylene fatty acid diesters; polyoxyethylene fatty acid monoesters; polyoxyethylene polyoxypropylene block polymers; acetylene alcohol; acetylene glycol; polyethoxylate of acetylene alcohol; acetylene glycol derivatives, such as polyethoxylate of acetylene glycol; fluorine-containing surfactants, such as FLUORAD (trademark, manufactured by Sumitomo 3M Co., Ltd.), MEGAFAC (trademark, manufactured by DIC Corporation), SURFLON (trademark, manufactured by Asahi Glass Co., Ltd.); or organosiloxane surfactants, such as KP341 (trademark, manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the aforementioned acetylene glycols include 3-methyl-1-butyne-3-ol, 3-methyl-1-pentin-3-ol, 3,6-dimethyl-4-octin-3,6-diol, 2,4,7,9-tetramethyl-5-decine-4,7-diol, 3,5-dimethyl-1-hexyn-3-ol, 2,5-dimethyl-3-10hexyn-2,5-diol, and 2,5-dimethyl-2,5-hexane-diol.

[0057] Examples of anionic surfactants include ammonium salts or organic amine salts of alkyldiphenyl ether disulfonic acid, ammonium salts or organic amine salts of alkyldiphenyl ether sulfonic acid, ammonium salts or organic amine salts of alkylbenzene sulfonic acid, ammonium salts or organic amine salts of polyoxyethylene alkyl ether sulfate, and ammonium salts or organic amine salts of alkyl sulfate.

[0058] Examples of amphoteric surfactants include 2-alkyl-N-carboxymethyl-N-20 hydroxyethylimidazolium betaine and lauric acid amidopropyl hydroxysulfone betaine.

[0059] Preferred surfactant metal oxides are selected from the list consisting of aluminum oxide, calcium oxide, silica, and zinc oxide. Such surfactant metal oxides are preferably present as fine particles, more preferably as nanoparticles, and are optionally surface-treated.

[0060] Preferred surfactant organic compounds are surfactant nonpolymer compounds or surfactant polymer organic compounds, wherein the surfactant nonpolymer compounds are preferably selected from a list consisting of alcohols, alkoxylates, aromatic compounds, ketones, esters, modified ureas, silanes, siloxanes, and soap-based foam stabilizers, which are optionally functionalized and / or modified; the surfactant polymer compounds are preferably selected from a list consisting of hydroxypolyesters, maleinate resins, polyacrylates, polyethers, polyesters, polysilanes, silicone resins, and waxes, which are optionally functionalized and / or modified; and which optionally exist as copolymers. In preferred embodiments, the surfactant organic compounds are used as a solution.

[0061] Preferred silanes are polyether-modified silanes, polyester-modified silanes, and polyether-polyester-modified silanes. Preferred siloxanes are polyether-modified siloxanes, polyester-modified siloxanes, and polyether-polyester-modified siloxanes.

[0062] Preferred polyacrylates are modified polyacrylates, preferably silicone-modified polyacrylates, polyether macromer-modified polyacrylates, and silicone and polyether macromer-modified polyacrylates, which exist optionally as copolymers.

[0063] Preferred polysilanes are polyether-modified polysilanes (e.g., PEG-silane 6-9), polyester-modified polysilanes, and polyether-polyester-modified polysilanes.

[0064] Preferred silicone resins include polyether-modified polysiloxane, preferably polyether-modified polydialkylsiloxane, more preferably polyether-modified polymethylalkylsiloxane, most preferably polyether-modified polydimethylsiloxane and polyether-modified hydroxyfunctional polydimethylsiloxane; polyester-modified polysiloxane, preferably polydialkylsiloxane, more preferably polyester-modified polymethylalkylsiloxane, most preferably polyester-modified polydimethylsiloxane and polyester-modified hydroxyfunctional polydimethylsiloxane; polyether-polyester-modified polysiloxane, preferably polyether-polyester-modified polydialkylsiloxane, more preferably polyether-polyester-modified polymethylalkylsiloxane, most preferably polyether-polyester-modified polydimethylsiloxane and polyether-polyester-modified hydroxyfunctional polydimethylsiloxane; epoxy-functional polysiloxane, preferably epoxy-functional polydialkylsiloxane, more preferably epoxy-functional polymethylalkylsiloxane, most preferably These include epoxy-functional polydimethylsiloxanes; acrylic-functional polysiloxanes, preferably acrylic-functional polydialkylsiloxanes, more preferably acrylic-functional polymethylalkylsiloxanes, most preferably acrylic-functional polydimethylsiloxanes; polyether-modified acrylic-functional polysiloxanes, preferably polyether-modified acrylic-functional polydialkylsiloxanes, more preferably polyether-modified acrylic-functional polymethylalkylsiloxanes, most preferably polyether-modified acrylic-functional polydimethylsiloxanes; polyester-modified acrylic-functional polysiloxanes, preferably polyester-modified acrylic-functional polydialkylsiloxanes, more preferably polyester-modified acrylic-functional polymethylalkylsiloxanes, most preferably polyester-modified acrylic-functional polydimethylsiloxanes; and aralkyl-modified polysiloxanes, preferably aralkyl-modified polydialkylsiloxanes, more preferably aralkyl-modified polymethylalkylsiloxanes, most preferably aralkyl-modified polydimethylsiloxanes; these exist optionally as copolymers.

[0065] Preferred surfactants are commercially available from BYK-Chemie GmbH, Wesel, Germany and are provided as surface additives. Preferred surfactants are BYK-300, BYK-301, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315 N, BYK-320, BYK-322, BYK-323, BYK-325 N, BYK-326, BYK-327, BYK-329, BYK-330, BYK-331, BYK-332, BYK-333, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-350, BYK-352, BYK-354, BYK-355, BYK-356, BYK-358 N, BYK-359, BYK-360 P, BYK-361 N, BYK-364 P, BYK-366 P, BYK-368 P, BYK 370, BYK 375, BYK-377, BYK-378, BYK-381, BYK-390, BYK-392, BYK-394, BYK-399, BYK-2616, BYK-3400, BYK-3410, BYK-3420, BYK-3450, BYK-3451, BYK-3455, BYK-3456, BYK-3480, BYK-3481, BYK-3499, BYK-3550, BYK-3560, BYK-3565, BYK-3566, BYK-3750, BYK-3751, BYK-3752, BYK-3753, BYK-3754, BYK-3760, BYK-3761, BYK-3762, BYK-3763, BYK-3764, BYK-3770, BYK-3771, BYK-3780, BYK-3900 P, BYK 3902 P, BYK-3931 P, BYK 3932 P, BYK-3933 P, BYK-8020, BYK-8070, BYK-9890, BYK-DYNWET 800, BYK-S 706, BYK-S 732, BYK-S 740, BYK-S 750 N, BYK-S 760, BYK-S 780, BYK-S 782, BYK-SILCELAN 3700, BYK-SILCLEAN 3701, BYK-SILCLEAN 3710, BYK-SILCLEAN 3720, BYK-UV 3500, BYK-UV 3505, BYK-UV 3510, BYK-UVThe DISPERBYK (hereinafter referred to as "BYK") is selected from the BYKETOL series, including 3530, BYK-UV 3535, BYK-UV 3570, BYK-UV 3575, BYK-UV 3576; BYKETOL-AQ, BYKETOL-OK, BYKETOL-PC, BYKETOL-SPECIAL, BYKETOL-WA, and the NANOBYK series, including NANOBYK-3603, NANOBYK-3605, NANOBYK-3620, NANOBYK-3650, NANOBYK-3652, and NANOBYK-3822.

[0066] The wetting and dispersing agents used in the present invention are additives that provide both a wetting effect and / or a stabilizing effect to formulations containing fine solid particles. They result in a fine and uniform distribution of solid particles in the formulation medium, preferably a liquid formulation medium, ensuring that such systems remain stable over time. The formulation medium may include water and the entire range of organic solvents of various polarities. Furthermore, they improve the wetting properties of the solids and prevent particle aggregation by various mechanisms (e.g., electrostatic effects, steric effects, etc.).

[0067] Preferably, the wetting dispersant is an organic polymer or organic copolymer having a polar functional group selected from amino groups; amide groups; carbamate groups; carbonate groups; acidic groups, preferably boric acid groups, boronic acid groups, carboxylic acid groups, sulfate groups, sulfonic acid groups, phosphoric acid groups, and phosphinic acid groups; ester groups, preferably boric acid ester groups, boronic acid ester groups, carboxylic acid ester groups, sulfate ester groups, sulfonic acid ester groups, phosphoric acid ester groups, and phosphinic acid ester groups; ether groups; hydroxyl groups; keto groups; and urea groups, the organic polymer or copolymer may exist as a conjugate, derivative and / or salt, preferably as a salt. Preferred salts are ammonium salts, alkylammonium salts, alkylol ammonium salts, or alkali metal salts, for example, preferably Li, Na, K and Rb salts. The polar functional groups may also be referred to as pigment affinity groups or filler affinity groups. In preferred embodiments, the wetting dispersant is used as a solution.

[0068] More preferably, the wetting dispersant is an organic polymer or organic copolymer selected from acrylates; amides; carboxylic acids; and esters, the organic polymer or copolymer may exist as a conjugate, derivative and / or salt, preferably as a salt, which may be further functionalized with one or more polar functional groups as described above. Preferred salts are ammonium salts, alkylammonium salts, alkylol ammonium salts, or alkali metal salts, for example, preferably Li, Na, K, Cs, and Rb salts. In preferred embodiments, the wetting dispersant is used as a solution.

[0069] The wetting and dispersing agent may exist as a mixture, preferably as a mixture with a polysiloxane copolymer.

[0070] Preferred wetting and dispersing agents are commercially available from BYK-Chemie GmbH, Wesel, Germany. Preferred wetting and dispersing agents are ANTI-TERRA-202, ANTI-TERRA-203, ANTI-TERRA-204, ANTI-TERRA-205, ANTI-TERRA-210, ANTI-TERRA-250, ANTI-TERRA-U, ANTI-TERRA-U 80, ANTI-TERRA-U 100, BYK-151, BYK-153, BYK-154, BYK-155 / 35, BYK-156, BYK-220 S, BYK-1160, BYK-1162, BYK-1165, BYK-9076, BYK-9077, BYK-GO 8702, BYK-GO 8720, BYK-P 104, BYK-P 104 S, BYK-P 105, BYK-SYNERGIST 2100, BYK-SYNERGIST 2105, BYK-W 900, BYK-W 903, BYK-W 907, BYK-W 908, BYK-W 909, BYK-W 940, BYK-W 961, BYK-W 966, BYK-W 969, BYK-W 972, BYK-W 974, BYK-W 980, BYK-W 985, BYK-W 995, BYK-W 996, BYK-W 9010, BYK-W 9011, BYK-W 9012, BYKJET-9131, BYKJET-9132, BYKJET-9133, BYKJET-9142, BYKJET-9150, BYKJET-9151, BYKJET-9152, BYKJET-9170, BYKJET-9171, BYKUMEN, DISPERBYK, DISPERBYK-101 N, DISPERBYK-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-107, DISPERBYK-108, DISPERBYK-109, DISPERBYK-110, DISPERBYK-111, DISPERBYK-115, DISPERBYK-118, DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK-145, DISPERBYK-161, DISPERBYK-162, DISPERBYK-162 TF, DISPERBYK-163, DISPERBYK-163TF、DISPERBYK-164、DISPERBYK-165、DISPERBYK-166、DISPERBYK-167、DISPERBYK-167 TF、DISPERBYK-168、DISPERBYK-168 TF、DISPERBYK-169、DISPERBYK-170、DISPERBYK-171、DISPERBYK-174、DISPERBYK-180、DISPERBYK-181、DISPERBYK-182、DISPERBYK-184、DISPERBYK-185、DISPERBYK-187、DISPERBYK-190、DISPERBYK-190 BF、DISPERBYK-191、DISPERBYK-192、DISPERBYK-193、DISPERBYK-194 N、DISPERBYK-199、DISPERBYK-199 BF、DISPERBYK-2000、DISPERBYK-2001、DISPERBYK-2008、DISPERBYK-2009、DISPERBYK-2010、DISPERBYK-2012、DISPERBYK-2013、DISPERBYK-2014、DISPERBYK-2015、DISPERBYK-2015 BF、DISPERBYK-2018、DISPERBYK-2019、DISPERBYK-2022、DISPERBYK-2023、DISPERBYK-2025、DISPERBYK-2026、DISPERBYK-2030、DISPERBYK-2050、DISPERBYK-2055、DISPERBYK-2059、DISPERBYK-2060、DISPERBYK-2061、DISPERBYK-2062、DISPERBYK-2070、DISPERBYK-2080、DISPERBYK-2081、DISPERBYK-2096、DISPERBYK-2117、DISPERBYK-2118、DISPERBYK-2150、DISPERBYK-2151、DISPERBYK-2152、DISPERBYK-2155、DISPERBYK-2155 TF、DISPERBYK-2157、DISPERBYK-2158、DISPERBYK-2159、DISPERBYK-2163、DISPERBYK-2163These are TF, DISPERBYK-2164, DISPERBYK-2190, DISPERBYK-2200, DISPERBYK-2205, DISPERBYK-2290, DISPERBYK-2291, DISPERPLAST-1142, DISPERPLAST-1148, DISPERPLAST-1150, DISPERPLAST-1180, DISPERPLAST-I, and DISPERPLAST-P.

[0071] Preferred adhesion promoters include block copolymers, preferably high molecular weight block copolymers; copolymers containing functional groups, preferably hydroxy-functional copolymers containing acidic groups; styrene-ethylene / butylene-styrene block copolymers (SEBS) functionalized with maleic anhydride; carboxylated SEBS functionalized with maleic anhydride; SEBS functionalized with glycidyl methacrylate; polyolefin block copolymers functionalized with maleic anhydride; and ethylene octene copolymers functionalized with maleic anhydride; as well as polymers containing functional groups, preferably polymers containing acidic groups, and polypropylene functionalized with maleic anhydride. In preferred embodiments, the adhesion promoter is used as a solution.

[0072] Preferred adhesion promoters are commercially available from BYK-Chemie GmbH, Wesel, Germany. Preferred adhesion promoters include BYK-4500, BYK-4509, BYK-4510, BYK-4511, BYK-4512, BYK-4513, SCONA TPKD 8102 PCC, SCONA TSIN 4013 GC, SCONA TSPOE 1002 GBLL, SCONA TPPP 2112 FA, SCONA TPPP 2112 GA, SCONA TPPP 8112 GA, SCONA TSKD 9103, SCONA TPPP 8112 FA, SCONA TPKD 8304 PCC, and SCONA TSPP 10213 GB.

[0073] Preferred polymer matrices include polymethyl methacrylate, polyvinylpyrrolidone, polycarbonate, polystyrene, polymethylpentene, and silicone.

[0074] In some embodiments, one or more formulation media are solution media and / or dispersion media. In preferred embodiments, one or more formulation media are selected from water, amides, aromatic hydrocarbons, non-aromatic hydrocarbons, alcohols, carboxylic acids, esters, ethers, ketones, diketones, lactones, and mixtures thereof. In particularly preferred embodiments, one formulation medium is water. In even more particularly preferred embodiments, the formulation medium is water.

[0075] In a preferred embodiment of the present invention, the formulation is an ink formulation suitable for inkjet printing. Typical requirements for the ink formulation are a surface tension in the range of 20 mN / m to 30 mN / m and a viscosity in the range of 5 mPa·s to 10 mPa·s.

[0076] Method for preparing the compound of the present invention In another aspect, the present invention relates to a method for preparing a formulation described in any one of the above claims, comprising at least the following steps: (X) (I) Formula (I) and / or (II) [ka] (In the formula, X represents a cation, m is 1, 2, or 3, preferably 1 or 2; n is an integer greater than or equal to 2, arbitrarily between 2 and 10 (in water), and preferably n is 1. [ka] (In the formula, X represents a cation, m is 1, 2, or 3, preferably 1 or 2. (II) A method comprising the step of mixing one or more metavanadates; and (II) a formulation medium.

[0077] Preferably, the cation is selected from the group consisting of ammonium cations, alkali metal cations, alkaline earth metal cations, and organic cations.

[0078] More preferably, the cation is Li + na + NH4 + , K + , Rb + , Cs + [N(C4H9)4] + [PPh4] + [H3N(C4H9)] + [H3N(C4H8)NH3] 2+ , and [N(CH3)3(C8H 17 )] + It is selected from the group consisting of the following.

[0079] More preferably, the metavanadate salt is selected from one or more elements of the group consisting of sodium metavanadate, potassium metavanadate, lithium metavanadate, cesium metavanadate, tetrabutylammonium metavanadate, and ammonium.

[0080] Preferably, the total amount of metavanadate is in the range of 0.01 to 50% by weight, preferably 0.1 to 30% by weight, and more preferably 0.5 to 15% by weight, based on the total mass of the formulation.

[0081] Preferably, the formulation medium is a solution medium and / or a dispersion medium.

[0082] More preferably, the formulation medium is selected from water, alcohol, carboxylic acid, ether, ketone, amide, sulfone, and mixtures thereof.

[0083] Preferably, the formulation medium is selected from the list consisting of propylene glycol methyl ether, di(propylene glycol) methyl ether, propylene glycol methyl ether acetate, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, propylene carbonate, propylene glycol, water, and mixtures thereof.

[0084] Preferably, the pH of the formulation is in the range of 6 to 11, more preferably 7 to 9.

[0085] Preferably, the formulation further comprises (iii) one or more additives selected from surfactants, wetting and dispersing agents, adhesion promoters, and polymer matrices.

[0086] Method for preparing an optical metal oxide layer In another embodiment, a method for preparing an optical metal oxide layer, comprising the following steps (a) to (c): (a) A step of providing a compound, wherein the compound is (i) one or more metavanadates of formula (I) as defined herein above; and (ii) a compound medium; (b) A step of applying the compound to the surface of the substrate; (c) A step of converting the compound on the surface of the substrate into an optical metal oxide layer. A method including this is provided.

[0087] In a preferred embodiment of the present invention, the formulation provided in step (a) of a method for preparing an optical metal oxide layer is an ink formulation suitable for inkjet printing. Typical requirements for the ink formulation are a surface tension in the range of 20 mN / m to 30 mN / m and a viscosity in the range of 5 mPa·s to 10 mPa·s.

[0088] In a preferred embodiment of the method for preparing an optical metal oxide layer according to the present invention, in step (b), the formulation is applied to the surface of the substrate by deposition. Preferred deposition methods are drop casting, coating, or printing. More preferred coating methods are spin coating, spray coating, slit coating, or slot die coating. More preferred printing methods are flexographic printing, gravure printing, inkjet printing, EHD printing, offset printing, or screen printing. Spray coating and inkjet printing are most preferred.

[0089] Depending on the specific problem to be solved, it may be necessary to deposit the formulation as a homogeneous, dense, thin layer covering the entire surface of the substrate by a coating method, or to deposit the formulation locally in a structured manner as required by a printing method. Both coating and printing methods require formulations that are appropriately formulated to suit the physicochemical needs of the respective coating and printing methods, and to suit the specific needs of the substrate surface to be coated or printed.

[0090] For example, depending on the solid content and trench volume, step (b) may be performed one or more times, for example, two, three, four, five, or six times.

[0091] In a preferred embodiment of the method for preparing an optical metal oxide layer according to the present invention, the surface of the substrate is pretreated by a surface cleaning process. Preferred surface cleaning processes include silicon wafer cleaning processes such as those described in W. Kern, The Evolution of Silicon Wafer Cleaning Technology, J. Electrochem. Soc., Vol. 137, 6, 1990, 1887-1892 and New Process Technologies for Microelectronics, RCA Review 1970, 31, 2, 185-454. Such silicon wafer cleaning processes include wet cleaning processes with a cleaning solvent (e.g., isopropanol (IPA)); wet etching processes with hydrogen peroxide solutions (e.g., Piranha solutions, SC1, and SC2), choline solutions, or HF solutions; dry etching processes with chemical vapor etching, UV / ozone treatment, or glow discharge techniques (e.g., O2 plasma etching); and mechanical processes with brush scrubbing, fluid jets, or ultrasonic techniques (ultrasonic treatment). The surface of the substrate may also be pretreated by silane treatment or atomic layer deposition (ALD) processes. Surface pretreatment of the substrate plays a role in changing the hydrophobicity / hydrophilicity of the surface. This makes it possible to improve the adhesion and filling properties of the optical metal oxide layer on the substrate surface.

[0092] In more preferred embodiments, a wet cleaning process with a cleaning solvent (e.g., isopropanol (IPA)) is combined with one or more of the following: a wet etching process with a hydrogen peroxide solution (e.g., piranha solution, SC1, and SC2), a choline solution, or an HF solution; a dry etching process with chemical vapor etching, UV / ozone treatment, or glow discharge technology (e.g., O2 plasma etching); and a mechanical process with brush scrubbing, fluid jet, or ultrasonic technology (ultrasonic treatment).

[0093] In the most preferred embodiment, a wet cleaning process with a cleaning solvent (e.g., isopropanol (IPA)) is combined with a mechanical process with brush scrubbing, fluid jetting or ultrasonic technology (ultrasonic treatment), and is combined with a wet etching process with a hydrogen peroxide solution (e.g., piranha solution, SC1 and SC2), choline solution, or HF solution.

[0094] In a preferred embodiment of the present invention, step (b) of the method for preparing the optical metal oxide layer is carried out multiple times in succession, preferably 2 to 20 times, more preferably 2 to 10 times, and most preferably 2, 3, 4, or 5 times.

[0095] In a preferred embodiment of the method for preparing an optical metal oxide layer according to the present invention, in step (c), the compound is converted into an optical metal oxide layer on the surface of the substrate by exposure to heat treatment and / or radiation treatment.

[0096] Preferred heat treatments include exposure to high temperatures of up to 500°C. The heat treatment is not limited to any specific heat treatment method or duration. Those skilled in the art can determine a suitable heat treatment method and duration depending on the type of substrate and compound.

[0097] Preferred irradiation treatments include exposure to infrared (IR) light, visible (Vis) light, and / or ultraviolet (UV) light. IR light has a wavelength of >800 nm. Visible light has a wavelength of 400 to 800 nm. UV light has a wavelength of <400 nm and may include EUV (extreme UV). Irradiation treatments are not limited to any particular irradiation method or duration. Depending on the type of substrate and formulation, a person skilled in the art can determine a suitable irradiation method and duration.

[0098] In a more preferred embodiment of the method for preparing an optical metal oxide layer according to the present invention, in step (c), the formulation is converted into an optical metal oxide layer on the surface of a substrate by pre-baking (soft baking) at a temperature of 40 to 150°C, preferably 50 to 120°C, more preferably 60 to 100°C; and then baking (hard baking, sintering, or annealing) at a temperature of 150 to 600°C, preferably 250 to 550°C, more preferably 300 to 500°C.

[0099] Soft baking (also called pre-baking) serves to remove volatile, low-boiling-point components, such as volatile, low-boiling-point formulation media or additives, from drop-cast, coated, or printed films. Soft baking is preferably performed for 1 to 10 minutes. After soft baking, a layer of substrate with a film of metal oxide precursor or metal oxide precursor mixture attached is obtained. The film may still contain residual formulation media or additives.

[0100] In an alternative and more preferred embodiment of the method for preparing an optical metal oxide layer according to the present invention, soft baking can be omitted, and as a result, in step (c), the formulation is directly converted into an optical metal oxide layer on the surface of the substrate by baking (hard baking, sintering, or annealing) at a temperature of 150 to 600°C, preferably 250 to 550°C, and more preferably 300 to 500°C.

[0101] The purpose of baking (hard baking, sintering, or annealing) is to convert a layer of metal oxide precursor or metal oxide precursor mixture on the substrate into a metal oxide layer. Furthermore, the final properties of the metal oxide layer may be adjusted by the baking process. Baking is preferably carried out for 1 to 300 minutes, preferably 1 to 60 minutes, to achieve a refractive index (RI) of >1.6.

[0102] Soft baking and hard baking may be carried out in the ambient atmosphere or in an atmosphere with increased oxygen content to decompose undesirable organic components, thereby lowering the activation energy when the metal oxide layer is formed.

[0103] Conveniently, upon removal of the solvent, oligomeric species condensation can be induced, potentially forming 1D chains identical to those in the substrate trenches. This adaptable dimensionality facilitates the efficient deposition and organization of metavanadate within the substrate trenches. Due to their dimensionality, the 1D metavanadate chains may be shown to have a negligible tendency to form microcrystalline domains, thereby reducing undesirable light scattering at crystallite boundaries in the material film.

[0104] In a preferred embodiment of the method for preparing an optical metal oxide layer according to the present invention, the substrate is a patterned substrate including topographic features, and the metal oxide forms a coating layer that covers the surface of the substrate and fills the topographic features. As a result, the topographic features are filled and flattened by the metal oxide.

[0105] Preferred topographic features include, for example, gaps, grooves, surface relief grids, trenches, and vias. The topographic features may be uniformly or non-uniformly distributed across the surface of the substrate. Preferably, they are arranged on the surface of the substrate as an array or grid. The topographic features preferably have different lengths, widths, diameters, and aspect ratios. The topographic features preferably have an aspect ratio of 1:20 to 20:1, more preferably 1:10 to 10:1. The aspect ratio is defined as the height (or depth) of the structure relative to its width. In terms of dimensions, the depth of the topographic features is preferably in the range of 10 nm to 10 μm, more preferably 50 nm to 5 μm, and most preferably 100 nm to 1 μm.

[0106] The topographic features are also preferably inclined at a specific angle, for example, 10 to 80°, preferably 20 to 60°, more preferably 30 to 50°, and most preferably about 40°. Such inclined topographic features are also referred to as slanted or blazed topographic features.

[0107] Furthermore, it may be necessary to fill topographic features completely or to a specific level locally with an optical metal oxide layer, but if there are no topographic features to fill, it is not necessary to cover the adjacent surfaces of the substrate.

[0108] Therefore, the method for preparing an optical metal oxide layer according to the present invention further includes the following step (d): (d) Preferably, the step includes removing a portion of the optical metal oxide layer covering the top of the topographic feature to obtain a filled topographic feature, wherein the overburden of the optical metal oxide layer on top of the topographic feature is reduced to preferably 0 to 100 nm, more preferably 0 to 50 nm, and most preferably 0 to 20 nm.

[0109] Step (d) is performed after steps (a) to (c) of the method according to the present invention. Preferably, the removal of a portion of the optical metal oxide layer covering the top of the topography in step (d) is performed by using a surface cleaning process as described above. Preferred surface cleaning processes are silicon wafer cleaning processes such as those described in W. Kern, The Evolution of Silicon Wafer Cleaning Technology, J. Electrochem. Soc., Vol. 137, 6, 1990, 1887-1892 and New Process Technologies for Microelectronics, RCA Review 1970, 31, 2, 185-454. Such silicon wafer cleaning processes include wet etching processes with hydrogen peroxide solutions (e.g., Piranha solution, SC1, and SC2), choline solutions, or HF solutions; dry etching processes with chemical vapor etching, UV / ozone treatment, or glow discharge technology (e.g., O2 plasma etching); and mechanical processes with brush scrubbing, fluid jet, or ultrasonic technology.

[0110] The substrate is preferably a substrate for an optical device. Preferred substrates are made of inorganic or organic materials, preferably inorganic materials. Preferred inorganic materials include materials selected from the list consisting of ceramics, glass, fused silica, sapphire, silicon, silicon nitride, quartz, and transparent polymers or resins. The shape of the substrate is not particularly limited, but a sheet or wafer is preferred.

[0111] In step (b) of the method for preparing an optical metal oxide layer, the formulation is applied to the surface of a substrate, which may be either the surface of the substrate's base material or the surface of a layer of a different material from the substrate's base material, and such layer is formed before the formulation is applied.

[0112] In this way, a series of different layers (stacks of layers) can be formed on top of each other. Such stacks of layers may also be structured, and such structures typically have dimensions on the nanometer scale with respect to at least diameter, width, and / or aspect ratio.

[0113] Use of compound In a third aspect, the present invention relates to the use of a formulation for preparing an optical metal oxide layer, the formulation comprising one or more metavanadates of formula (1) as defined above herein, and a formulation medium.

[0114] Optical devices In a fourth aspect, an optical device is provided comprising an optical metal oxide layer which can be obtained or is obtained by a method for preparing an optical metal oxide layer according to the present invention as described above. The optical device is preferably an augmented reality (AR) and / or virtual reality (VR) device.

[0115] The present invention will be further illustrated by the following embodiments, which should not be construed as limiting. Those skilled in the art will recognize that various modifications, additions, and substitutions can be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims. [Examples]

[0116] Sodium metavanadate, ammonium metavanadate, cesium metavanadate, vanadium oxide, tetrabutylammonium hydroxide, and all solvents were purchased from Sigma Aldrich and used without further purification, unless otherwise noted elsewhere. Lithium metavanadate was purchased from Alfa Aesar and used without further purification. Potassium metavanadate was purchased from Thermo Scientific and used without further purification.

[0117] Analysis and measurement methods The thickness, refractive index (n), and absorption coefficient (k) of the metal oxide layer were measured using polarization analysis. Measurements were performed using a JAWoollam M2000V(I)SE polarization analyzer and three different incidence angles (65°, 70°, 75°), and averaged across five spots. To obtain the refractive index (n) and absorption coefficient (k), a Gen-OSC fitting model with three fitted Gaussian oscillators was applied, and the measurement data was analyzed using JAWoollam's CompleteEase software. Optical constants were averaged from five different points measured on the sample, either after soft baking or hard baking.

[0118] The optical spectra of any sheets and substrates coated or uncoated with the metal oxide layer described in this invention were recorded using an Agilent Cary 7000 UV / Vis / NIR spectrophotometer with UMA settings. Measurements were performed using dual-beam mode, a scanning speed of 600 nm / min, a spectral bandwidth of 4 nm, and unpolarized light, with a spectral window of 350 nm to 700 nm. Transmission measurements were performed at an incident angle of 6° relative to the surface normal of the sample. The detector was positioned at 180° relative to the incident light. Reflectance measurements were performed at an incident angle of 6° relative to the surface normal of the sample, with the detector angle set to 12° relative to the incident light. The absorption of the sample was calculated using Equation 1 (where A represents the absorption of the coated sample, R represents the reflectance of the sample, and T represents the transmission of the sample). A=1-(R+T) Equation 1

[0119] SEM images were recorded using a Magellan 400L thermofisher.

[0120] Substrates, typically wafers, were coated using a Suess spin coater (Ossila L2001A). The spin coating process for planar substrates was as follows: deposition of 1.0 ml of coating on a stationary quartz wafer, followed by a 10-second spin interval at 2000 RPM. After spin coating, the coated substrates underwent a pre-bake at 100°C for 1 minute to remove solvent residue, followed by a bake at a higher temperature. The coated layers were baked at 150°C, 200°C, 300°C, 400°C, and 500°C for 10 minutes, unless otherwise specified. Pre-baking and layer baking were performed using a high-temperature IKA C-MAG HS 7 hot plate capable of reaching temperatures up to 500°C. The conditions and parameters described above apply to all experimental examples below, unless other conditions are explicitly mentioned elsewhere.

[0121] Throughout all coating experiments (e.g., spectroscopic and polarization analysis measurements) that typically require a flat, unstructured support for metal oxides, we used 2-inch diameter quartz and / or silicon wafers.

[0122] A structured substrate, typically a silicon wafer, was used as a square die with an edge length of 1.8 cm. This wafer die was cut and cleaved from a parent wafer, typically with a diameter of 8 inches. The structure was formed by depositing SiO2 / SiN on the wafer surface. x The structures were formed and arranged as stacks of layers composed of the following. The dimensions of the structures (e.g., width and length of the trench cross-section) were based on the configuration of the Sematech mask 854. Typically, but not limited to, cleavage of cross-sections perpendicular to the trench array providing widths of 40 nm to 50 nm was used as the primary target trench structure to investigate the packing behavior of wet and chemically coated metal oxide precursors and / or metal oxides during thermal conversion of the metal oxide precursors. In addition to the above, cross-sections of trench arrays with widths of 100 nm and 150 nm were also used to investigate the packing of trenches with metal oxides.

[0123] The structured wafer dies were coated by spin coating unless otherwise specified. For this purpose, a typical volume of 0.1 ml of the coating formulation per die was pipetted and cast onto the wafer surface. The formulation was spread on the surface and allowed to stand for 1 minute, after which a final spin-off process was performed at 2,000 rpm for an additional 10 seconds. The soft bake and hard conditions for the structured wafer dies were selected to be the same as or identical to those already described for the flat substrates.

[0124] Throughout all coating experiments (e.g., spectroscopic and polarization analysis measurements) that typically require a flat, unstructured support for metal oxides, we used 2-inch diameter quartz and / or silicon wafers.

[0125] Metabanadate formulation Example 1: Sodium metavanadate (NaVO3) was dissolved in water at a concentration of 4% by weight by heating.

[0126] One mL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 RPM for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, followed by baking at 150°C for 10 minutes unless otherwise specified.

[0127] Table 1 shows the polarization analysis data for the coated silicon substrate.

[0128] [Table 1]

[0129] Figure 7 shows the UV / Vis absorption spectrum of a coated fused silica substrate, normalized to a 100 nm thick film, demonstrating its dependence on processing temperature.

[0130] Figures 8A and 8B show SEM images of a coated and trenched silicon nitride substrate, illustrating the trench filling behavior.

[0131] Example 2: Lithium metavanadate (LiVO3) was dissolved in water by heating (3.47 wt%). 1 mL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 rpm for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, and then baked at 150°C for 10 minutes unless otherwise specified.

[0132] Table 2 shows the polarization analysis data for the coated silicon substrate.

[0133] [Table 2]

[0134] Figures 9A and 9B show the UV / Vis absorption spectra of a coated fused silica substrate, normalized to a 100 nm thick film, demonstrating the dependence on processing temperature.

[0135] Example 3: Lithium metavanadate (LiVO3) was dissolved in a 40:60 mixture of water and propylene glycol methyl ether by heating (3.47% by weight).

[0136] One mL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 rpm for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, followed by baking at 150°C for 10 minutes.

[0137] Table 3 shows the polarization analysis data for the coated silicon substrate.

[0138] [Table 3]

[0139] Example 4: Ammonium metavanadate (NH4VO3) was dissolved in water by heating (4% by weight).

[0140] One mL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 rpm for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, and then baked at 150°C for 10 minutes unless otherwise specified.

[0141] Table 4 shows the polarization analysis data for the coated silicon substrate.

[0142] [Table 4]

[0143] Figures 10A and 10B show the UV / Vis absorption spectra of a coated fused silica substrate, normalized to a 100 nm thick film, demonstrating the dependence on processing temperature.

[0144] Figures 11A and 11B show SEM images of a coated and trenched silicon nitride substrate, illustrating the trench filling behavior.

[0145] Example 5 Potassium metavanadate (KVO3) was dissolved in water to a concentration of 4.5% by weight by heating.

[0146] One ml of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 rpm for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, followed by baking at 150°C for 10 minutes unless otherwise specified.

[0147] Table 5 shows the polarization analysis data for the coated silicon substrate.

[0148] [Table 5]

[0149] Figures 12A and 12B show the UV / Vis absorption spectra of a coated fused silica substrate, normalized to a 100 nm thick film, demonstrating the dependence on processing temperature.

[0150] Example 6 Cesium metavanadate (CsVO3) was dissolved in water to a concentration of 7.6% by weight by heating.

[0151] One mL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 rpm for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, and then baked at 150°C for 10 minutes unless otherwise specified.

[0152] Table 6 shows the polarization analysis data for the coated silicon substrate.

[0153] [Table 6]

[0154] Figure 13 shows the UV / Vis absorption spectrum of a coated fused silica substrate, normalized to a 100 nm thick film, demonstrating its dependence on processing temperature.

[0155] Example 7 Tetrabutylammonium metavanadate ((C4H9)4NVO3) was dissolved in propylene glycol methyl ether by stirring to a concentration of 11.2% by weight.

[0156] 100 μL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 rpm for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, and then baked at 150°C for 10 minutes unless otherwise specified.

[0157] Table 7 shows the polarization analysis data for the coated silicon substrate.

[0158] [Table 7]

[0159] Figures 14A and 14B show the UV / Vis absorption spectra of a coated fused silica substrate, normalized to a 100 nm thick film, demonstrating the dependence on processing temperature.

[0160] Example 8: A mixture of sodium metavanadate (NaVO3) and lithium metavanadate (LiVO3) is used in VO3 - The solution was dissolved in water by heating to a total concentration of 0.34 M. 1 mL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 RPM for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, followed by baking at 150°C for 10 minutes.

[0161] The following optical parameters are revealed from polarization analysis measurements of coated silicon substrates.

[0162] [Table 8]

[0163] Figure 15 shows UV / vis spectroscopy of a coated fused silica substrate, normalized for a 100 nm thick film, exhibiting the following absorption curve.

[0164] Example 9: A mixture of sodium metavanadate (NaVO3) and potassium metavanadate (KVO3) is used in VO3 - The solution was dissolved in water by heating to a total concentration of 0.34 M. 1 mL of this solution was deposited onto a silicon or fused silica substrate and spin-coated at 2000 RPM for 10 seconds. The coated substrate was then pre-baked at 100°C for 1 minute, followed by baking at 150°C for 10 minutes.

[0165] The following optical parameters are revealed from polarization analysis measurements of coated silicon substrates.

[0166] [Table 9]

[0167] Figures 16A and 16B show UV / vis spectroscopy results of a coated fused silica substrate, normalized for a 100 nm thick film, exhibiting the following absorption curves. Specifically, Figure 16B is an enlarged view of Figure 16A. [Explanation of symbols]

[0168] 1 RI 02 Material 02 2 RI 01 Material 01 3. Substrate (e.g., glass) 4. Diffraction of incident light, represented by a thick arrow. 5. Total Internal Reflection (TIR) ​​of Light 6 Waveguides 7. Stack of structured layers with gaps (trenches) 8. Substrate (e.g., glass or silicon) 9. Material overburden (e.g., high refractive index materials or high etching resistance materials) 10. Materials that provide gap filling (e.g., high refractive index materials or high etching resistance materials) 11 Cavity 12. Formulations of high refractive index materials (e.g., metal oxide precursors) (e.g., inks) 13. High refractive index materials (e.g., metal oxides) that optionally provide gap filling in a concave shape. 14. Overbarden layer (optional) 15 Energy

Claims

1. A formulation for preparing an optical metal oxide layer, wherein at least, (i) an oligomer of a metavanadate salt, preferably the oligomer is an oligomer of the same metavanadate salt or an oligomer of a mixture of metavanadates, preferably the oligomer is of formula I 【Chemistry 1】 (In the formula, X represents a cation, m is 1, 2, or 3, preferably 1 or 2. n is an integer greater than or equal to 2, and can be arbitrarily selected as being between 2 and 10 (in water). Oligomers of metavanadate represented by; and (ii) Formulation medium A compound containing the following:

2. The formulation according to claim 1, wherein the cation X is independently selected from the group consisting of ammonium cations, alkali metal cations, alkaline earth metal cations, and organic cations when they appear.

3. where the cation is Li ＋ , Na ＋ , NH ４ ＋ , K ＋ , Rb ＋ , Cs ＋ , [N(C ４ H ９ ) ４ , ＋ , [PPh ４ , ＋ , [H ３ N(C ４ H ９ )], ＋ , [H ３ N(C ４ H ８ )NH ３ , ２＋ , and [N(CH ３ )(C ３ H ８ )], １７ and is selected from the group consisting of ＋ the formulation according to claim 1 or 2.

4. The formulation according to any one of claims 1 to 3, wherein the metavanadate salt is selected from the group consisting of sodium metavanadate, potassium metavanadate, lithium metavanadate, cesium metavanadate, tetrabutylammonium metavanadate, and ammonium metavanadate.

5. The formulation according to any one of claims 1 to 4, wherein the total amount of the metavanadate is in the range of 0.01 to 50% by weight, preferably 0.1 to 30% by weight, and more preferably 0.5 to 15% by weight, based on the total mass of the formulation.

6. The formulation according to any one of claims 1 to 5, wherein the formulation medium is a solution medium and / or a dispersion medium.

7. The formulation according to any one of claims 1 to 6, wherein the formulation medium is selected from water, alcohol, carboxylic acid, ether, ketone, amide, sulfone, and mixtures thereof.

8. The formulation according to any one of claims 1 to 7, wherein the formulation medium is selected from the list consisting of propylene glycol methyl ether, di(propylene glycol) methyl ether, propylene glycol methyl ether acetate, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, propylene carbonate, propylene glycol, water, and mixtures thereof.

9. The formulation according to any one of claims 1 to 8, wherein the pH of the formulation is in the range of 6 to 11, preferably 7 to 9.

10. The formulation according to any one of claims 1 to 9, wherein the formulation further comprises one or more additives selected from surfactants, wetting and dispersing agents, adhesion promoters, and polymer matrices (iii).

11. A method for preparing the compound according to any one of claims 1 to 10, comprising at least the following steps: (X) (I) Formula (I) and / or (II) 【Chemistry 2】 (X represents a cation, m is 1, 2, or 3, preferably 1 or 2; n is an integer greater than or equal to 2, optionally between 2 and 10 (in water), and preferably n is 1); 【Transformation 3】 (X represents a cation, m is 1, 2, or 3, preferably 1 or 2. One or more metavanadates; and (II) Formulation medium A method comprising the step of adding; Preferably, the cation X is independently selected from the group consisting of ammonium cations, alkali metal cations, alkaline earth metal cations, and organic cations; More preferably, the cation is Li ＋ Na ＋ NH ４ ＋ _K ＋ , Rb ＋ , Cs ＋ [N(C) ４ H ９ ) ４ ] ＋ [PPh ４ ] ＋ [H ３ N(C) ４ H ９ )] ＋ [H ３ N(C) ４ H ８ ) NH ３ ] ２＋ , and [N(CH ３ ) ３ (C ８ H １７ )] ＋ Selected from the group consisting of; More preferably, the metavanadate salt is selected from one or more elements of the group consisting of sodium metavanadate, potassium metavanadate, lithium metavanadate, cesium metavanadate, tetrabutylammonium metavanadate, and ammonium; Preferably, the total amount of the metavanadate is in the range of 0.01 to 50% by weight, preferably 0.1 to 30% by weight, and more preferably 0.5 to 15% by weight, based on the total mass of the formulation; Preferably, the formulation medium is a solution medium and / or a dispersion medium; More preferably, the formulation medium is selected from water, alcohol, carboxylic acid, ether, ketone, amide, sulfone, and mixtures thereof; Preferably, the compound medium is selected from the list consisting of propylene glycol methyl ether, di(propylene glycol) methyl ether, propylene glycol methyl ether acetate, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, propylene carbonate, propylene glycol, water, and mixtures thereof; Preferably, the pH of the compound is in the range of 6 to 11, preferably 7 to 9; Preferably, the formulation further comprises one or more additives selected from surfactants, wetting and dispersing agents, adhesion promoters, and polymer matrices (iii).

12. Use of the formulation according to any one of claims 1 to 10 for preparing an optical layer containing metavanadate.

13. A method for preparing an optical metal oxide layer, comprising the following steps (a) to (c): (a) a step of providing the formulation according to any one of claims 1 to 10; (b) the step of applying the compound to the surface of the substrate; (c) A step of converting the compound on the surface of the substrate into an optical metal oxide layer. Methods that include...

14. The method according to claim 13, wherein in step (b), the compound is applied to the surface of the substrate by deposition.

15. The method according to claim 13 or claim 14, wherein in step (c), the compound is converted into an optical metal oxide layer on the surface of the substrate by exposure to heat treatment and / or radiation treatment.

16. The method according to any one of claims 13 to 15, wherein in step (c), the formulation is converted into an optical metal oxide layer on the surface of the substrate by pre-baking at a temperature of 40 to 130°C, preferably 80 to 110°C; and then baking at a temperature of 100 to 600°C, preferably 150 to 450°C.

17. The method according to any one of claims 13 to 16, wherein the substrate is a patterned substrate having topographic features on its surface.

18. An optical device comprising an optical metal oxide layer, which can be obtained by the method described in any one of claims 13 to 17, or prepared by using the formulation described in any one of claims 1 to 10.

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