High transmission neutral colour Anti-reflection coating for patterned solar glass

Abstract

This invention discloses a patterned solar glass with a neutral colour anti- reflection coating (ARC) designed to enhance light transmission and optical performance The dual-side structured glass features a smoother side coated with a two-layer anti-reflection coating. The bottom layer is formulated from a silane precursor, a hydrolyzing agent, an acid catalyst, porosity-enhancing agents, and a combination of solvents, achieving a refractive index of 1.4 to 1.5. The top layer is a nano-composite-based AR coating with a refractive index of 1.25 to 1.35 is applied on the bottom layer. The layers are chemically bonded via a roll-coating process, with precise thickness control wherein, the bottom layer ranges from 180–210 nm and the top layer ranges from 140–160 nm. This gradient refractive index structure results in a transmission gain of 2.3% and minimizing Fresnel reflection losses. The coating ensures neutral colour appearance and uniform light transmission, improving omnidirectional performance under varying light angles.

Description

High Transmission Neutral Colour Anti-Reflection Coating for Patterned Solar GlassFIELD OF THE INVENTION

[0001] The invention pertains to the field of solar glass coatings, specifically to a neutral colour anti-reflection coating applied to patterned solar glass surfaces with a gradient refractive index for enhanced light transmission.BACKGROUND

[0002] With the improvement of people’s environmental awareness and to cope with the energy crisis and environmental pollution, solar energy has been the focus of global attention and has become more and more popular as a clean energy source. With the rapid development of solar cell industry, continuous optimization of solar cell photovoltaic modules has happened. Consequently, the conversion efficiency (conversion of solar light into electric power) of crystalline silicon or thin-film solar cells in solar photovoltaic modules has approached the limit. The ultra-white photovoltaic glass used currently has a high transmittance in the visible light band, and its transmittance is about 90- 91.5%, but due to the difference in refractive index between the photovoltaic glass and air, the photovoltaic glass still shows a loss of transmission of about 8-10 % of visible light. Therefore, it is necessary to increase the light transmittance of photovoltaic glass to improve the conversion efficiency of solar cells, thereby increasing the output power of the solar cell photovoltaic module.

[0003] According to tests by European research institutes, if the solar glass transmittance increases by 5%, the efficiency of solar flat panel collectors will increase by 6-10%, and the photovoltaic conversion efficiency of photovoltaic solar cells will increase by 3-6%. Hence, anti-reflective coatings are needed on the glass surface. The purpose of these coatings is to maximize sunlight entering solar cells by minimizing reflection at the air-glass interface. One of the simplest and most effective ways to make the glass have anti-reflective properties is to apply one or more layers of film on the surface of the photovoltaic glass and use the interferencecancellation of the film to reduce the unnecessary reflection of sunlight on the glass surface thereby increasing the transmittance of glass.

[0004] In various applications where, visual aesthetics play a pivotal role, the demand for anti-reflective coatings with a neutral colour, or essentially colourless appearance, has become increasingly crucial. Despite the undeniable benefits in power output, the residual colour stemming from reflection poses a significant challenge, impacting the overall appearance of photovoltaic (PV) modules. One of the primary issues with traditional anti -reflective coatings lies in their tendency to have a peak transmission point at a specific wavelength. This characteristic leads to undesirable colour effects, compromising the overall aesthetics of coated surfaces. Over the past decade, the prevalent use of single-layer antireflection (SLAR) coatings in commercial crystalline silicon PV modules has led to modules with a distinct blueish appearance.

[0005] To address these challenges and improve the power output and visual appeal of PV modules, the development of Neutral Anti-Reflective coatings has emerged as a solution. The key feature of these coatings is their ability to maintain a ‘flat’ reflectance or transmittance spectrum over the visible spectrum. This characteristic ensures that the reflection profile remains consistent, resulting in a neutral colour appearance. By imparting a more natural and sheer-black appearance to PV modules, these coatings contribute to the modules' integration into the architectural design of the building. This aesthetic improvement ensures that solar panels coated with Neutral Anti-Reflective coatings seamlessly blend with the roof, enhancing the overall visual harmony and making them appear as an integral and attractive part of the building structure.

[0006] While the state-of-the-art relating to neutral anti reflective coating is relatively advanced today through creation of a flat reflectance or transmittance spectrum over the visible spectrum as explained, often results in an overall reduction in the flat transmission curves.

[0007] To overcome the above problem there is an urgent need within the industry to develop a method for preparing photovoltaic anti -reflection coated glass that addresses these challenges, wherein the transmission is not compromised while creating a neutral colour coating. There is also a need to develop such high transmitting neutral coatings which offer a low-cost process, a straightforward technical route suitable for large-scale industrial application, with minimal chromatic aberrations. Such advancements will not only contribute to the efficiency of solar energy systems but also enhance the seamless integration of PV modules into various architectural settings. Hence this invention is directed towards providing an improved composition of Neutral Anti Reflective Coating (ARC), which is relatively simple and is highly effective.SUMMARY

[0008] This invention aims to provide an enhanced composition for a Neutral Anti- Reflective Coating with high transmission efficiency. The coating consists of duallayer functional coating designed to achieve a gradient refractive index. The first layer i.e., bottom layer includes components primarily composed of silanes, which create a network-forming structure and generate porosity. The second, top layer contains a higher proportion of nanoparticle silica and other precursors, contributing to a gradient refractive index. This composite structure ensures the anti-reflective coating maintains a neutral color while delivering exceptionally high transmission performance.

[0009] Embodiment of the present disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems recognized by the inventors in conventional systems. The inventors have worked and developed an enhanced composition for a Neutral Anti-Reflective Coating (ARC) without compromising transmission efficiency.

[0010] An object of the present invention is to provide a neutral colour antireflection film or coating having improved and uniform light transmission efficiency across the wavelength range of 380-1100 nm.

[0011] Another object of the present invention is to provide a neutral colour antireflection film or coating which is resistant to mechanical degradation due to the robust silica network.

[0012] Still another object of the invention is to provide a neutral colour antireflection film or coating that is easy to prepare and apply.

[0013] Yet another object of the invention is to provide a neutral colour anti reflection coating that is optimized to minimize chromatic aberrations and provide a neutral colour reflection similar to natural daylight.

[0014] Yet another object of the invention is to provide a method for preparing and applying a neutral anti reflection film or coating having high light transmission efficiency on the surface of solar glass.

[0015] Patterned solar glass is commonly used in photovoltaic applications, where maximizing light transmission efficiency is crucial. Traditional anti -reflection coatings often exhibit coloration issues, impacting the overall performance of solar glass. The present invention addresses this challenge by providing a neutral colour Anti Reflection Coating (ARC) with a gradient refractive index. The present invention relates to a neutral colour anti-reflection coating (ARC) applied to patterned solar glass, wherein the glass has a smoother side and a rough side wherein the ARC is developed on the smoother side. The ARC includes a bottom layer and a top layer, both applied using a roller coating process. The bottom layer is meticulously formulated using a Silane precursor, hydrolysing agent, acid catalyst, porosity enhancing agents and solvents. A silica network is created through the hydroxylation and condensation of a silane precursor and provides strong bonding to the glass. The top layer is developed using Nano-composite based anti-reflective coating compositions. The strong bonding of the silane network to the glass surface,coupled with its integration with the Nano-composite top layer, results in a single anti reflection coating, thereby ensuring the high stability of the neutral coating that contributes to the creation of a gradient refractive index.

[0016] These and other features and advantages of the present invention will become apparent from the following description of the invention. It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the below-mentioned detailed description.BRIEF DESCRIPTION OF THE FIGURES

[0017] The summary above, as well as the following detailed description of illustrative embodiment, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, example constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers. Embodiment of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:

[0018] Figure 1 illustrates solar glass with dual layer functional coating in accordance with an exemplary embodiment of the present disclosure.

[0019] Figure 2 illustrates the graph plot of transmittance (%) versus wavelength (nm) of samples in accordance with an exemplary embodiment of the present disclosure.

[0020] Figure 3 illustrates the graph plot of reflectance (%) versus wavelength (nm) of samples in accordance with an exemplary embodiment of the present disclosure.

[0021] Figure 4(a) and 4(b) illustrates the prepared glass samples with conventional coating and neutral anti-reflection coating (ARC), respectively in accordance with an exemplary embodiment of the present disclosure.DETAILED DESCRIPTION

[0022] The following detailed description illustrates embodiment of the present disclosure and manners by which they can be implemented. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0023] The term “horizontal” as used herein will be understood to be defined as a plane parallel to the plane or surface of the substrate, regardless of the orientation of the substrate. The term “vertical” will refer to a direction perpendicular to the horizontal as previously defined. Terms such as “above”, “below”, “bottom”, “top”, “side” (e.g. sidewall), “higher”, “lower”, “upper”, “over”, and “under”, are defined with respect to the horizontal plane. The term “on” means there is direct contact between the elements. The term “above” will allow for intervening elements.

[0024] The person skilled in the art will recognize many variations, alternatives, and modifications of the embodiment of the present disclosure. It should be understood that this invention is not limited to the particular methodology, protocols, and the like, described herein and as such may vary. The terminology used herein is for the purpose of describing particular embodiment only and is not intended to limit the scope of the present invention, which is defined solely by the claims.

[0025] The PV modules require maximum solar power irradiation to obtain high Power conversion efficiency to minimize the Fresnel reflection losses due to a gradient in the refractive index. In particular, the solar PV module front surface is covered with a glass that should exhibit high transmission in the wavelength range of 380 - 1100 nm. In the field of photovoltaic technology, the search for high-efficiency anti-reflection coated glass designed for the encapsulation of solar modules has beenmet with challenges. The existing methods often come with high production costs, intricate technical processes, and are not conducive to large-scale industrial applications. Furthermore, achieving colour neutrality and minimizing chromatic aberrations in the appearance of photovoltaic modules remains a rare accomplishment. To achieve minimum reflectance, fine control over coating thickness and refractive index is essential. Solar glass coated with conventional anti -reflective coating has an unattractive blueish reflection colour. Standard anti-reflective coatings have a peak transmission point at a particular wavelength. However, with the present invention, Neutral Anti-Reflective coating light transmission is more across all wavelengths. As a result, the “reflected” light is perceived as being neutral by the human eye - just like natural daylight, without compromising the performance.

[0026] The present invention discloses a patterned solar glass having a thickness ranging from 1.5 mm to 5 mm. This solar glass is distinguished by its dual-sided structure, featuring a smoother side and a rough side. The neutral colour Anti Reflection Coating (hereinafter referred as ARC) is specifically developed on the smoother side and comprises a bottom layer and a top layer, both applied through a dip-coating method, roller coating method or the like, preferably roller coating method. Referring to Figure 1, a solar glass with dual-layer functional coating configuration 100 is employed on a solar glass 102 facilitating the formation of a composite structure comprising the glass substrate 102, a bottom layer 104, and a top layer 106 to form a high transmittance neutral colour anti reflection film.

[0027] The bottom layer is meticulously formulated using a Silane precursor, hydrolysing agent, acid catalyst, porosity enhancing agents and a first and a second solvent. Silane precursors are commonly used in the formulation of thin films and contribute to the adhesion, hydrophobicity, crosslinking, and film-forming properties of anti-reflection coatings for solar glass. These properties collectively enhance the performance, durability, and longevity of the coating, ultimately improving the efficiency of solar cells by minimizing light reflection The Silane precursor used forthe preparation in bottom layer may be selected from the alkoxysilanes group chemicals such as tetramethyl orthosilicate, tetraethyl orthosilicate, 3- glycidoxypropyltrimethoxysilane,2-glycidoxyethyltrimethoxysilane, trimethoxymethylsilane, triethoxymethylsilane or the like, preferably tetraethyl orthosilicate.

[0028] Silane precursors, such as alkoxysilanes, contain hydrolysable groups (such as alkoxy groups, e.g., methoxy or ethoxy). Hydrolysing agents, often water or vapours from the atmosphere, initiate the hydrolysis reaction by breaking these groups and forming hydroxyl groups. After hydrolysis, the reactive hydroxyl groups on the silane precursors can undergo a condensation reaction. In this step, the hydroxyl groups combine to form siloxane bonds, resulting in the formation of a three-dimensional network. This network is a critical component of the coating, contributing to its mechanical strength, adhesion, and overall stability. The hydrolysis and condensation reactions lead to the formation of a polymerized network of silica (SiCh) or a hybrid silica-based material. This network forms a thin film on the surface of the solar glass. These hydrolysis and condensation reactions influence the refractive index of the resulting silica-based coating. By adjusting the concentration and type of silane precursors and the hydrolysing agent, it is possible to control the refractive index of the coating.

[0029] A robust silica network is created through the hydroxylation and condensation of the silane precursor. This network, characterized by a refractive index of 1.4 to 1.5, forms chemical links with the glass surface, ensuring stability in the coating and enhancing the durability and longevity of the anti -reflection coating.

[0030] Acid catalysis expedites the condensation reaction between the formed silanol groups. This process involves the combination of hydrolyzed silane molecules, resulting in the creation of siloxane bonds. The acid catalyst promotes the polymerization of these bonds, leading to the formation of a three-dimensional network that constitutes the anti-reflection coating. The acid catalyst may be selectedfrom hydrofluoric acid, phosphoric acid, toluenesulfonic acid, polystyrene sulfonate, ammonia solution, nitric acid, sulphuric acid, perchloric acid or the like, preferably Hydrochloric acid and nitric acid.

[0031] Solvents are used to dissolve the silane precursors, which are often organosilanes or alkoxysilanes. This dissolution is a crucial step as it allows for the formation of a homogeneous solution or dispersion of the silane precursor in the solvent. This homogeneous solution is then used to apply a uniform coating on the solar glass surface. The first and second solvents may be selected from Acetone, Ethanol, Ethyl acetate, Hexane, Acetonitrile, Chloroform, Methanol, Benzene, Toluene, Diethyl ether, Acetic acid, Tetrachloroethylene, Cyclohexane, Isopropanol, Tetrahydrofuran, Dichloromethane or the like, preferably isopropanol.

[0032] Simultaneously, the top layer is developed using a Nano-composite based Antireflective Coating (ARC) composition. This second layer is carefully applied onto the pre-established bottom layer, making it apparently a single layer anti reflection layer and forming a cohesive structure. The thickness of the bottom layer ranges from 180 - 210 nm and the thickness of the top layer ranges from 140-160 nm. The refractive index of the top layer ranges from 1.25 to 1.4, contributing to the overall gradient refractive index on the smoother side of the glass.

[0033] Porosity is needed to reduce refractive index, but too high porosity level may deteriorate mechanical strength of the coating. Optimum porosity and pore size in an ARC does not only depend on the coating layer thickness, but also on other desired performance characteristics. Pore size should not be too large, to minimise light scattering and optimise transparency. Porosity enhancing agents are incorporated into the coating to create a porous structure. This porous structure helps in reducing the reflection of light at the interface between the air and the coating, allowing more light to pass through the coating and into the solar glass. The presence of these nanoparticles with spaces in between them helps to minimize the reflection losses. The role of porosity enhancing agents and binders in the composition of a neutralanti-reflection coating (ARC) for solar glass is to optimise the structure of the coating in a way that minimizes reflection and enhances light transmission. Binders play a crucial role in holding the porosity enhancing agents together and adhering them to the glass surface. The binder contributes to the overall stability, adhesion, and durability of the coating, ensuring that the nanoparticles maintain their intended structure over time. The porosity enhancing agents and binders work together to create a porous structure with desirable optical properties.

[0034] The introduction of porosity and the choice of certain materials with lower refractive indices can collectively contribute to lowering the effective refractive index of the anti-reflection coating and the adjacent layers (e.g., air and glass). This index matching helps in minimizing the reflection of light at the surface, allowing more light to penetrate the coating and reach the solar cells. The porosity binders may be selected from compounds selected from 3-glycidoxypropyltrimethoxysilane, 2- glycidoxyethyltrimethoxysilane, Polyethylene glycol tert-octyl phenyl ether, 3- glycidoxypropyltriethoxysilane, 2-glycidoxyethyltriethoxysilane, , Povidone (Polyvinylpyrrolidone, PVP), Hydroxypropyl cellulose (HPC), Microcrystalline cellulose (MCC), Polyethylene glycol (PEG), Gelatin, Carbomers, Sodium carboxymethyl cellulose (NaCMC) , methyl trimethoxysilane polymer, Carboxyl Methyl Cellulose or the like compounds individually or mixture thereof, preferably hydroxypropyl cellulose and methyl trimethoxysilane.

[0035] The composition for the bottom layer comprises (in wt%) of: a) Silane precursor - 2-6% b) Hydrolysing agent - 0.5- 5% c) Acid catalyst - 0.1 - 1.5% d) Solvent 1 - 10-75% e) Solvent 2 - 10- 75% f) Porosity enhancing agent - 0.01 - 1 %

[0036] The bottom layer is cured at 120 degrees Celsius for 5 minutes, resulting in a remarkable transmission gain of 1.5- 1.8 percent compared to uncoated glass. Subsequently, the application of the Nano -composite based ARC solution on the bottom layer yields a transmission gain of 2.3 percent, distinguishing the solar glass with a neutral colour appearance. The silica network of the bottom layer is strongly bonded to the upper side of the glass surface, creating stability in the coating. This network is further bonded to the Nano-composite based top layer that ensures the high stability of the coating and contributes to the creation of a gradient refractive index, thereby enhancing the overall anti-reflective properties of the coating. The combination of a high-transparency bottom layer and a nano-composite -based top layer results in a single layer anti reflective coating with improved performance in varying light angles, provides a neutral colour appearance by ensuring uniform light transmission across the wavelength range of 380-1100 nm and hence, may also be said as omnidirectional neutral colour anti reflection coating due to its omnidirectional properties.

[0037] Figure 2 presents a graph of transmittance (%) against wavelength (nm) for various samples, including an uncoated sample, conventional anti -reflective coatings (ARC), and Neutral Colour ARC applied to a glass surface. Transmittance (%) indicates the percentage of light that passes through the material, with higher values signifying greater light transmission and reduced reflection or absorption. The graph spans a wavelength range from 300 nm to 1200 nm, encompassing ultraviolet (UV), visible, and near-infrared (IR) light. The average transmittance (%) for the uncoated sample within the 380-1100 nm range is 89.5%. For the conventional ARC, the average transmittance (%) is approximately 91.9% over the same wavelength range, while the Neutral Colour ARC exhibits an average transmittance (%) of 91.8%. The graph illustrates the impact of each coating on transmittance across different wavelengths. Notably, the Neutral Colour ARC demonstrates more uniform transmittance throughout the entire wavelength range, maintaining a neutralappearance and achieving a transmittance gain of 2.3 % compared to the uncoated glass i.e. similar to conventional ARC.

[0038] Figure 3 discloses a graph of reflectance (%) against wavelength (nm) for uncoated samples, conventional anti-reflective coatings (ARC), and Neutral Colour ARC samples. Reflectance (%) represents the percentage of light reflected off the surface, with lower values indicating reduced reflection and increased light transmission or absorption, which is typically desired for anti -reflective coatings. The inventors noted that the Neutral Colour ARC of the present invention achieved a more consistent reduction in reflectance across a wider range of wavelengths, preserving a neutral appearance without color distortion, in contrast to the conventional ARC.

[0039] Fig 4(a) and 4(b) discloses the prepared glass samples with conventional coating and neutral anti -reflection coating (ARC), respectively. It is evident that the neutral ARC exhibits a neutral appearance, in contrast to the conventional ARC, which displays a bluish tint / colour.

[0040] A person skilled in the art will recognize many variations, alternatives, and modifications of the embodiment of the present disclosure. The present invention has both technical as well as economic significance with respect to the conventional anti reflection coating or the like. The neutral colour anti-reflection coating for patterned solar glass with a gradient refractive index provides an innovative solution with precise composition and enhances light transmission efficiency in photovoltaic applications. The ARC’s unique structure and manufacturing process contribute to its stability and superior performance which may used not only in solar industry but also in the field of optical fiber communication, multimedia digital products, IT industry, automobile industry, aerospace technology, computer monitor displays, eyeglasses, camera lenses, binoculars, telescopes, and other fields.

[0041] While a particular embodiment of the invention has been illustrated and described, modifications thereof will readily occur to those skilled in the art. It isunderstood that the various embodiment, details and composition of the Neutral ARC and their features described above may be interchanged among the various embodiment while remaining within the scope of the invention. Additionally, it is understood that various modifications could be made to any of the elements described herein above while remaining within the scope of the invention.

Claims

We claim:

1. A patterned solar glass with neutral colour anti reflection coating comprising: a dual side structured patterned solar glass having a smoother side and a rough side wherein, the smoother side is coated with a neutral colour anti- reflection coating comprising a bottom layer and a top layer, wherein, the said bottom layer is composed of a silane precursor, a hydrolyzing agent, an acid catalyst, porosity enhancing agents and at least two solvents the said top layer is composed of a nano-composite based antireflection coating composition having porosity enhancing agents and binders, wherein the said top layer is applied on the bottom layer, wherein, refractive index of said bottom layer ranges from 1.4 to 1.5 and the refractive index of top layer ranges from 1.25 to 1.35, thereby creating a gradient refractive index resulting in a transmission gain of 2.3% and exhibiting a neutral colour appearance by ensuring uniform light transmission, thereby enhancing the performance in varying light angles due to its omnidirectional properties.

2. The neutral colour anti reflection coating of claim 1, wherein the top layer is chemically bonded to the bottom layer via a roll coating process in a controlled environment to achieve uniform coating thickness.

3. The neutral colour anti relection coating of claim 1, wherein the combination of a high-transparency bottom layer and a nano-composite-based top layer results in a single anti reflection coating.

4. A patterned solar glass with neutral colour anti reflection coating comprising: a dual side structured patterned solar glass having a smoother side and a rough side wherein, the smoother side is coated with a neutral colour anti- reflection coating comprising a bottom layer and a top layer, wherein, the said bottom layer is composed essentially in terms of weight percent 2-6% of a silane precursor, 0.5-5% of a hydrolyzing agent, 0.1-1.5% of an acid catalyst, 10-75% of a first solvent, 10-75% of a second solvent and 0.01-1% porosity enhancing agents; and the said top layer is composed of a nano-composite based antireflection coating composition having porosity enhancing agents and binders, the said top layer is applied on the bottom layer, wherein, refractive index of said bottom layer ranges from 1.4 to 1.5 and the refractive index of top layer ranges from 1.25 to 1.35, thereby creating a gradient refractive index resulting in a transmission gain of 2.3% and exhibiting a neutral colour appearance by ensuring uniform light transmission, thereby enhancing the performance in varying light angles due to its omnidirectional properties.

5. The neutral colour anti reflection coating of claim 4, wherein the silane precursor in the bottom layer is selected from the group consisting of tetramethyl orthosilicate, tetraethyl orthosilicate, 3- glycidoxypropyltrimethoxysilane, 2-glycidoxyethyltrimethoxysilane, trimethoxymethylsilane, and triethoxymethylsilane, preferably tetraethyl orthosilicate.

6. The neutral colour anti reflection coating of claim 4, wherein the acid catalyst is selected from the group consisting of hydrofluoric acid, phosphoric acid, toluenesulfonic acid, polystyrene sulfonate, ammonia solution, nitric acid, sulfuric acid, and perchloric acid, preferably Hydrochloric acid and Nitric acid.

7. The neutral colour anti reflection coating of claim 4, wherein the solvents are selected from the group consisting of acetone, ethanol, ethyl acetate, hexane, acetonitrile, chloroform, methanol, benzene, toluene, diethyl ether, acetic acid, tetrachloroethylene, cyclohexane, isopropanol, tetrahydrofuran, and dichloromethane, preferably isopropanol and ethanol.

8. The neutral colour anti reflection coating of claim 4, wherein the hydrolysing agent may be selected from water and vapours present in the atmosphere, preferably water.

9. The neutral colour anti reflection coating of claim 4, wherein the top layer comprises porosity-enhancing agents and binders selected from the group consisting of 3-glycidoxypropyltrimethoxysilane, 2 glycidoxyethyltrimethoxysilane, polyethylene glycol tert-octyl phenyl ether, 3-glycidoxypropyltriethoxysilanes, 2-glycidoxyethyltriethoxysilane,povidone, hydroxypropyl cellulose, microcrystalline cellulose, polyethylene glycol, gelatin, carbomers, sodium carboxymethyl cellulose, methyl trimethoxysilane polymer, and carboxyl methyl cellulose, preferably hydroxypropyl cellulose and methyl trimethoxysilane polymer.

10. The neutral colour anti reflection coating of claim 4, wherein the bottom layer is cured at 120 °C for 5 minutes to form a silica network with a refractive index of 1.4 to 1.5.

11. The neutral colour anti reflection coating of claim 4, wherein the thickness of the bottom layer ranges from 180 - 210 nm and the thickness of the top layer ranges from 140-160 nm.

12. A method for manufacturing a high light transmittance patterned solar glass with a neutral colour anti reflection coating comprising the steps of:Step 1: Providing a glass substrate with a thickness of 1.5 mm to 5 mm and a dual-sided structure having a smoother side and a rough side;Step 2: Applying a bottom layer on the smoother side of glass surface via a dip-coating process, wherein the bottom layer comprises a silane precursor, a hydrolyzing agent, an acid catalyst, porosity enhancing agents and at least two solvents;Step 3: Curing the bottom layer at 120°C for 5 minutes to form a silica network with a refractive index of 1.4 to 1.5;Step 4: Applying a top layer over cured the bottom layer, wherein the top layer is a nano-composite-based anti-reflection coating with a refractive index of 1.25 to 1.35; andStep 5: Allowing the layers to bond chemically to form a gradient refractive index structure that minimizes Fresnel reflection losses across the wavelength range of 380-1100 nm and provides a neutral colour appearance by ensuring uniform light transmission, thereby enhancing the performance in varying light angles due to its omnidirectional properties.

13. A patterned solar glass with neutral colour anti reflection coating of claim 1, wherein the neutral colour coating may be used not only in solar industry but also in the field of optical fiber communication, multimedia digital products, IT industry, automobile industry, aerospace technology, computer monitor displays, eyeglasses, camera lenses, binoculars, telescopes, and other fields.

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