Description:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)

TITLE: AN ENHANCED SOLAR CONTROL COATINGS FOR GLASS FACADES AND METHOD THEREOF

APPLICANT DETAILS:
(a) NAME: Asahi India Glass Limited
(b) NATIONALITY: IN
(c) ADDRESS: A-2/10, 1st Floor WHS DDA Marble Market, Kirti Nagar, New Delhi- 110015

PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of the invention and the manner in which it is to be performed:
AN ENHANCED SOLAR CONTROL COATINGS FOR GLASS FACADES AND METHOD THEREOF
Field of Invention:
The present invention relates to an optical coating with enhanced visual appeal, reduced glare along with achieving properties of improved solar control and thermal insulation, which are also resistance to corrosion and moisture-related damage.
Background of the Invention
The following background discussion includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication expressly or implicitly referenced is prior art.
The utilization of coated films in various applications such as glass window units, laminated windows, automotive sunroofs, and facade buildings has become commonplace, especially in structures exposed to direct sunlight. Direct sunlight comprises various components of rays emanating from the sun's heat, as elucidated through electromagnetic radiation. Among these rays, infrared (IR) rays pose a significant challenge as they contribute substantially to the generation of solar heat. However, IR rays also pose health risks to humans, including sunburns and other related health hazards, when exposed for prolonged periods. Therefore, mitigating the impact of IR radiation has become a critical concern in the development of coated films for solar control applications.
To mitigate the impact of solar heat, particularly infrared (IR) radiation from the electromagnetic spectrum, the developed films must meet specific performance criteria, including the Solar Heat Gain Coefficient (SHGC), Solar Factor (SF), and lower thermal conductivity, particularly for building applications. These performance parameters are crucial for ensuring effective solar control and energy efficiency in structures exposed to direct sunlight.
The Solar Heat Gain Coefficient (SHGC) or Solar Factor (SF) represents the ratio between the energy entering a room or enclosed space through glazing and the incident solar energy. Essentially, it quantifies how much solar heat is transmitted through the glazing into the interior space. Lower SHGC or SF values indicate better solar control, as less solar heat is transmitted, thereby reducing the need for cooling and enhancing overall energy efficiency.
To assess and evaluate these performance parameters, various standards such as ISO (International Organization for Standardization), EN (European Norms), and NFRC (National Fenestration Rating Council) are employed. These standards provide guidelines and methodologies for testing and measuring the solar control properties of coated films and glazing systems. Adhering to these standards ensures consistency and reliability in assessing the performance of solar control coatings across different products and applications.
As discussed, the primary objective of utilizing solar control coatings with lower Solar Factor (SF) and Solar Heat Gain Coefficient (SHGC) values is to effectively regulate heat, particularly in hot environments. By incorporating these coatings into glass windows for fenestration walls, the aim is to maintain cooler indoor temperatures during the hot summer months, despite high ambient conditions. This exemplifies the inherent beauty and efficacy of solar control heat-regulated coatings in mitigating heat transfer and enhancing comfort within interior spaces.
Moreover, the concept of selectivity, defined as the ratio of the amount of light transmitted inside a building to the solar heat gain factor, plays a crucial role in achieving optimal solar control performance. A higher selectivity indicates a greater transmission of visible light while minimizing the transmission of heat. However, in certain cases, maintaining a balance between high light solar gain and lower SHGC values can pose challenges, particularly in achieving desired color shades within the developed coating stack.
Thus, there is a need of coating, which comprises following features:
• which exhibits a transmission range from 10% to 70%, providing optimal light control and energy efficiency.
• where the glass side reflection ranges from 5% to 30%, enhancing the visual appeal and reducing glare.
• where the film side reflection ranges from 2% to 20%, contributing to improved solar control and thermal insulation.
• with a selectivity (the ratio of visible light transmission to solar heat gain coefficient) of more than 1.0 to 1.5 for both monolithic glass units (MGU) and integrated glass units (IGU) to have a high energy efficiency and occupant comfort.
• has color shades of the product towards neutral, green, blue, and grey shades, which are achieved through precise control of the coating process and material composition.
• improved control of solar UV and infrared transmission, which enhances the glass's ability to reduce heat gain and protect interior furnishings from UV damage.
• With enhanced durability of the coatings or high resistance to wear and tear in various environmental conditions.
• with strong adhesion properties
• with long-term performance and resistance to corrosion and moisture-related damage.
The present invention provides a glass coating comprising layer stacks with varying combinations and process parameters. The present invention achieves the desired balance between high light solar gain and lower SHGC values, while also offering flexibility in achieving desired color shades to meet specific aesthetic and functional requirements. This innovative approach enhances the versatility and applicability of solar control coatings, making them suitable for a wide range of architectural and building applications in diverse environmental conditions.
Objective of the Invention:
The primary objective of the present invention is to overcome the drawback associated with prior art.
Another object of the present invention is to provide layer of stack focuses on controlling process defects like pinholes in the solar control layer stack by determining the flipping point by adjusting the nitrogen gas, pressure to voltage ratio during the tuning of the functional layer material.
Another object of the present invention is to provide optimized process in producing defect-free glass, minimizing issues like debris and cluster particle formation on the sputter target and walls of the chamber.
Another object of the present invention is to provide optimized process which enhances the durability of the coating stack and offering better thermal insulation and conductivity with a lower SHGC. Furthermore, the product provides superior thermal insulation when used in Insulated Glazing Units (IGUs).
Summary of the Invention:
In an aspect the present invention provides an enhanced solar control coatings for glass facades comprising:
a) a glass substrate (100) with at least two outer surfaces in which a first outer surface is incident to solar light and a second outer surface on which a layer of coating is applied;
b) a first dielectric layer (101) applied on the second outer surface of the glass substrate (100) comprises silicon nitride (Si3N4);
c) a first functional layer (102) comprises titanium nitride (TiN) deposited over the first dielectric layer (101);
d) a second functional layer (103) comprises nickel chromium nitride (NiCrN) deposited over the first functional layer (102); and
e) a second dielectric layer (104) comprises silicon nitride (Si3N4) deposited over the second functional layer (103);
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).
In an embodiment, the glass substrate (100) comprises a clear float glass substrate or a tinted glass substrate has thickness ranging from 2mm to 12 mm.
In an embodiment, the tinted glass comprises glasses that have shade of green or blue or dark grey or bronze is configured to improve the control of solar UV rays and infrared transmission.
In an embodiment, the emissivity of the functional layer is 0.25 to 0.42.
In an aspect the present invention provides a five-layer enhanced solar control coatings for glass facades comprising:
a) depositing a dielectric layer of silicon nitride (101) over a glass substrate (100);
b) depositing a first functional layer of titanium nitride (102) on the dielectric layer of silicon nitride (101);
c) depositing a second functional layer of nickel chromium nitride (103) on the first functional layer of titanium nitride (102); and
d) depositing a second dielectric layer of silicon nitride (104) on the second functional layer of nickel chromium nitride (103)
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).
In an aspect, the present invention provides layer deposition on the clear float glass substrate is performed by a physical vapor deposition (PVD) method with large area RF/DC magnetron sputtering.
In an aspect, the present invention provides the layer deposition process which is performed in a high vacuum environment with a base pressure of 10 x E-6 mbar.
In an aspect, the present invention provides layer deposition process in which argon gas is used to create a plasma of inert atmosphere and nitrogen gas is used to provide and maintain the layer stoichiometry for the functional layer and dielectric layer for tuning the layer deposition process.
Detailed description of drawings:
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of their scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings in which:

Figure 1: Illustrate four-layer stack of the present invention;
Figure 2: Illustrate five-layer stack of the present invention;
Figure 3: Illustrate six-layer stack of the present invention
Figure 4: shows comprehensive Analysis of Transmission, Selectivity, and Energy Performance from the spectral curves which are measured from UV-Visible Spectrophotometer.
Figure 5: shows FESEM images of coating defects caused by Fe particle contamination, confirmed by EDAX analysis.
Detailed description:
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.

The terms “comprises”, “comprising”, “includes”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.
In an embodiment, the present invention provides layer of stack focuses on controlling process defects like pinholes in the solar control layer stack by determining the flipping point by adjusting the nitrogen pressure to voltage ratio during the tuning of the functional layer material.
In an embodiment, the present invention provides optimized process in producing defect-free glass, minimizing issues like debris and cluster particle formation on the sputter target and walls of the chamber.
In an embodiment, the present invention provides optimized process which enhances the durability of the coating stack and offering better thermal insulation and conductivity with a lower SHGC. Furthermore, the product provides superior thermal insulation when used in Insulated Glazing Units (IGUs).
The Invention thus provides a glass coating contributing to following technical features:
• such that the coated glass product exhibits a transmission range from 10% to 70%, providing optimal light control and energy efficiency.
• Such that the glass side reflection ranges from 5% to 30%, enhancing the visual appeal and reducing glare.
• Such that the film side reflection ranges from 2% to 20%, contributing to improved solar control and thermal insulation.
• Coatings are applied to a variety of glasses, including clear float glass and tinted glass in shades such as green, blue, and dark grey. These coatings are designed to enhance the glass's durability and performance characteristics.
• The thickness of both clear float and tinted glasses ranges from 2 mm to 12 mm, allowing for flexibility in application and meeting various structural and aesthetic requirements.
• The product aims to achieve a selectivity (the ratio of visible light transmission to solar heat gain coefficient) of more than 1.0 to 1.5 for both monolithic glass units (MGU) and integrated glass units (IGU). This ensures high energy efficiency and occupant comfort.
• Using clear float glass, we have developed color shades of the product towards neutral, green, blue, and grey shades. These shades are achieved through precise control of the coating process and material composition.
• Using tinted glass such as green, blue, and dark grey, we have improved the control of solar UV and infrared transmission. This enhances the glass's ability to reduce heat gain and protect interior furnishings from UV damage.
• The developed product can be used in fenestration buildings, with annealed or post-thermal treatment. The durability of the coatings has been tested with dry abrasion for 1000 strokes, achieving a grade of 9 to 10 according to the EN 1096 standard. This indicates high resistance to wear and tear in various environmental conditions.
• The product has passed the Taber adhesion test with 500 Rotations/strokes, demonstrating strong adhesion properties. Additionally, it has undergone acid and base chemical tests, with a color tolerance variation of ±3 before and after the acid test, according to the EN 1096 standard. This confirms the coating's chemical resistance and stability.
• Salt spray and humidity tests for all coatings were passed; samples were monitored for 21 days with no discoloration in the product's aesthetics. This ensures the product's long-term performance and resistance to corrosion and moisture-related damage.

In an embodiment, the present invention provides an enhanced solar control coatings for glass facades comprising:
a) a glass substrate (100) with at least two outer surfaces in which a first outer surface is incident to solar light and a second outer surface on which a layer of coating is applied;
b) a first dielectric layer (101) applied on the second outer surface of the glass substrate (100) comprises silicon nitride (Si3N4);
c) a first functional layer (102) comprises titanium nitride (TiN) deposited over the first dielectric layer (101);
d) a second functional layer (103) comprises nickel chromium nitride (NiCrN) deposited over the first functional layer (102); and
e) a second dielectric layer (104) comprises silicon nitride (Si3N4) deposited over the second functional layer (103);
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).
In an embodiment, the glass substrate (100) comprises a clear float glass substrate or a tinted glass substrate has thickness ranging from 2mm to 12 mm.
In an embodiment, the tinted glass comprises glasses that have shade of green or blue or dark grey or bronze is configured to improve the control of solar UV rays and infrared transmission.
In an embodiment, the emissivity of the functional layer is 0.3 to 0.4.
In an embodiment, the present invention provides a method of depositing five-layer enhanced solar control coatings for glass facades, comprising:
a) depositing a dielectric layer of silicon nitride (101) over a glass substrate (100);
b) depositing a first functional layer of titanium nitride (102) on the dielectric layer of silicon nitride (101);
c) depositing a second functional layer of nickel chromium nitride (103) on the first functional layer of titanium nitride (102);
d) depositing a second dielectric layer of silicon nitride (104) on the second functional layer of nickel chromium nitride (103); and
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).
In an aspect, the present invention provides layer deposition on the clear float glass substrate is performed by a physical vapor deposition (PVD) method with large area RF/DC magnetron sputtering.
In an aspect, the present invention provides the layer deposition process which is performed in a high vacuum environment with a base pressure of 10 x E-6 mbar.
In an aspect, the present invention provides layer deposition process in which argon gas and nitrogen gas is used to create a plasma state for tuning the layer deposition process.
In an aspect, the present invention provides layer deposition on the clear float glass substrate is performed by a physical vapor deposition (PVD) method with large area RF/DC magnetron sputtering.
In an aspect, the present invention provides the layer deposition process which is performed in a high vacuum environment with a base pressure of 10 x E-6 mbar.
In an aspect, the present invention provides layer deposition process in which argon gas is used to create plasma of inert atmosphere and nitrogen gas is used to provide and maintain the layer stoichiometry for the functional layer and dielectric layer for tuning the layer deposition process.
In another embodiment, figure 1 shows the four-layer stack of the present invention. The four-layer stack where a functional layer of titanium nitride (TiN) with an additional layer of Nicr is sandwiched between two dielectric layers of silicon nitride (Si3N4) on the top and bottom sides of the glass. The NiCrN layer acts as an additional functional layer, enhancing the IR reflection and providing a more balanced color shade in both transmission and reflection modes. This arrangement improves the solar control properties by positioning the NiCrN layer in a way that optimizes the IR reflection and color balance.
In an embodiment, the enhanced solar control coatings for glass facades comprises:
a) a glass substrate (100) with at least two outer surfaces in which a first outer surface is incident to solar light and a second outer/inner surface on which a layer of coating is applied;
b) a first dielectric layer (101) applied on the second outer surface of the glass substrate (100) comprises silicon nitride (Si3N4);
c) a first functional layer (102) comprises titanium nitride (TiN) deposited over the first dielectric layer (101);
d) a second dielectric layer (104) comprises silicon nitride (Si3N4) deposited over the second functional layer (103);
e) blocking layer of Nichrome nitride, positioned above and/or below the first functional layer;
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).

In an embodiment, the glass substrate (100) comprises a clear float glass substrate or a tinted glass substrate comprising the thickness ranging from 2mm to 12 mm.

In an embodiment, the first blocking layer of Nichrome nitride positioned above the first functional layer and a second blocking layer of Nichrome nitride positioned below the first functional layer.

In an embodiment, the first blocking layer of Nichrome nitride positioned above the first functional layer and the second blocking layer of Nichrome nitride positioned below the first functional layer is replaced by a third dielectric layer of Titanium oxide and fourth dielectric layer of Titanium oxide respectively.

In an embodiment, the top layers of atleast a second functional layer comprising Titanium Nitride placed over said first dielectric layer and a third dielectric layer of silicon nitride over said layer of Titanium Nitride.

In an embodiment, the top layers of atleast a second functional layer comprising Titanium Nitride placed over said first dielectric layer followed by a blocking layer of Nichrome nitride and a third dielectric layer of silicon nitride over said layer of Titanium Nitride.

In an embodiment, the tinted glass comprises glasses comprising shades of green or blue or dark grey or bronze is configured to improve the control of solar UV rays and infrared transmission.

In an embodiment, the emissivity of the coating ranges from 0.25 to 0.42.

In an embodiment, the selectivity of the coating ranges from 1.0 to 1.5 for both monolithic glass units (MGU) and integrated glass units (IGU).

In an embodiment, the thickness of the layers for 45% transmission, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness ranging from 26 to 103nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness ranging from 3 to 35nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness ranging from 5 to 45nm;
d) first and/or second blocking layers of Nichrome nitride present in the thickness ranging from 1 to 3nm;
e) third dielectric layer of Titanium oxide present in the thickness ranging from 6 to 12nm and fourth dielectric layer of Titanium oxide is present in the thickness range of 10 to 16nm respectively;
f) top layers of atleast a second functional layer comprising Titanium Nitride placed over said first dielectric layer present in the thickness ranging from 10 to 20nm and a third dielectric layer of silicon nitride over said layer of Titanium Nitride present in the thickness ranging from 27 to 38nm;
g) the top layers of atleast a second functional layer comprising Titanium Nitride present in the thickness ranging from 10 to 20nm placed over said first dielectric layer followed by a blocking layer of Nichrome nitride present in the thickness ranging from 1 to 3nm and a third dielectric layer of silicon nitride over said layer of Titanium Nitride present in the thickness ranging from 15 to 38nm.

In an embodiment, the coating comprises 1st dielectric layer present in the thickness of 26nm, 2nd functional layer in the thickness of 26 to 30nm while the third dielectric layer in the thickness of 34nm.
In an embodiment, the coating comprises 1st dielectric layer present in the thickness of 35 to 38nm, 2nd functional layer in the thickness of 10nm, third dielectric layer in the thickness of 7 to 13nm, fourth functional layer in the thickness of 14 to 18nm, 5th dielectric layer in the thickness of 28nm to 36nm.
In an embodiment, the coating comprises 1st dielectric layer present in the thickness of 29 to 48nm, 2nd functional layer in the thickness of 23 to 28nm, third blocking layer in the thickness of 1nm, fourth dielectric layer in the thickness of 34 to 40nm.
In an embodiment, the coating comprises 1st dielectric layer present in the thickness of 37 to 45nm, 2nd blocking layer in the thickness of 1nm, third functional layer in the thickness of 26nm to 27nm, fourth dielectric layer in the thickness of 37 to 41nm.
In an embodiment, the coating comprises 1st dielectric layer present in the thickness of 35nm, 2nd blocking layer in the thickness of 1nm, third functional layer in the thickness of 21nm to 24nm, fourth blocking layer in the thickness of 1nm, 5th dielectric layer present in the thickness of 38 to 43nm.
In an embodiment, the coating comprises 1st dielectric layer present in the thickness of 37nm, 2nd blocking layer in the thickness of 1nm, third dielectric layer in the thickness of 5nm to 6nm, fourth functional layer in the thickness of 11nm, fifth blocking layer in the thickness of 17nm, 6th dielectric layer present in the thickness of 33 to 35nm.
In an embodiment, the coating comprises 1st dielectric layer present in the thickness of 24nm, 2nd dielectric layer in the thickness of 9nm, third functional layer in the thickness of 29nm, fourth dielectric layer in the thickness of 13nm, fifth dielectric layer in the thickness of 20nm.

In an embodiment, the coating for the thickness of the layers for 30% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 103nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 36nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 26nm.

In an embodiment, the coating for the thickness of the layers for 55% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 39nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 25nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 41nm.
In an embodiment, the coating for the thickness of the layers for 65% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 44nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 16nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 43nm.

In an embodiment, the coating for the thickness of the layers for 70% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 47nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 12nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 44nm.

In an embodiment, the coating for the thickness of the layers for 30% transmission for a green shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 91nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 37nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 33nm.

In an embodiment, the coating for the thickness of the layers for 45% transmission for a green shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 18nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 26nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 32nm.

In an embodiment, the coating for the thickness of the layers for 55% transmission for a green shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 27nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 21nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 38nm.

In an embodiment, the coating for the thickness of the layers for 30% to 45% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 25 to 94nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23 to 35nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 22 to 28nm.

In an embodiment, the coating for thickness of the layers for 55% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 46nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 37nm.

In an embodiment, the coating for thickness of the layers for 45% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness range of 46nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 37nm.

In an embodiment, the coating for the thickness of the layers for 45% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness range of 46nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 37nm.

In an embodiment, the stack comprises following layers to achieve Blue shade with transmission of 38 to 65%, reflection glass side of 7 to 20 %, reflection glass side of 3 to 15%:
a) First Dielectric layer in the thickness ranging from 54 to 60nm;
b) First Functional layer in the thickness ranging from 1 to 5 nm;
c) Second Functional layer in the thickness ranging from 4 to 35nm;
d) Second Dielectric layer in the thickness ranging from 26 to 69nm;
e) Third Functional layer 1 in the thickness ranging from 8 to 10nm;
f) Fourth Functional layer 1 in the thickness ranging from 1 to 5 nm;
g) Third Dielectric layer in the thickness ranging from 23 to 59nm.

In an embodiment, the method of preparing solar control coatings for glass facades comprises following steps:
a) depositing a dielectric layer of silicon nitride (101) over a glass substrate (100);
b) depositing a first functional layer of titanium nitride (102) on the dielectric layer of silicon nitride (101);
c) depositing a second functional layer of nickel chromium nitride (103) on the first functional layer of titanium nitride (102); and
d) depositing a second dielectric layer of silicon nitride (104) on the second functional layer of nickel chromium nitride (103)
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).
The layer deposition on the clear float glass substrate is performed by a physical vapor deposition (PVD) method with large area RF/DC magnetron sputtering. The layer deposition process is performed in a high vacuum environment with a pressure of 10 x E-6 mbar. While performing layer deposition process argon gas and nitrogen gas is used to create a plasma state for tuning the layer deposition process.
In an embodiment, the 3 layer stack comprises following layers:

Further, below table 1 shows four-layer stack power as shown in figure 2 and its colour/optical characteristics.

In another embodiment, the four layer stack comprises:

In another embodiment, figure 2 shows the five layer stack of the present invention. The five layer stack alternates between silicon nitride (Si3N4) and titanium nitride (TiN) layers, with Si3N4 at the ends and TiN layers in between them. This figure illustrates a five-layer stack. It starts and ends with silicon nitride (Si3N4) layers, with two nickel chromium nitride (NiCrN) layers sandwiching a titanium nitride (TiN) layer in between them. This arrangement combines the properties of NiCrN and TiN to achieve specific optical or functional properties, such as enhanced IR reflection and color balance.
Further, below table 2 shows five-layer stack power as shown in figure 2 and its colour/optical characteristics.

In another embodiment, figure 3 shows the six-layer stack, it begins with a silicon nitride (Si3N4) layer, followed by a titanium nitride (TiN) layer, then another silicon nitride (Si3N4) layer. This pattern repeats once more before ending with a nickel chromium nitride (NiCrN) layer. The alternating layers of Si3N4 and TiN, followed by NiCrN, suggest a complex structure aimed at achieving specific optical or functional properties, potentially related to multiple layers of interference or enhanced performance in solar control applications.
Below table shows the optical parameters of the six layer stack of the present invention:

In the present invention, the thickness of the layers can be varied by adjusting the gas ratios of argon and nitrogen during the deposition process. This allows for fine-tuning the optical and thermal properties of the coating, achieving specific color shades and improving solar control performance.
In an embodiment, the invention focuses on controlling process defects such as pinholes by optimizing the production process. This includes determining the flipping point through changes in nitrogen pressure to voltage ratio, which helps prevent pinholes and other defects like debris, cluster particles, and haze.
In an embodiment, the coating applied by the process of the present invention demonstrate high durability, passing dry abrasion tests with 1000 to 1500 strokes, acid and base tests, and salt spray tests. This ensures the coatings are suitable for both single glaze units and Insulated Glazing Units (IGUs), providing better thermal insulation and conductivity with a lower Solar Heat Gain Coefficient (SHGC).
In an embodiment, the 45% Transmission product range comprises the following layer stacks:
Maximum
layer stack 1st Design (STS) 2nd Design
(STSTS) 3rd design (STNS) 4th Design
(SNTS) 5th Design
(SNTNS) 6th Design (SNTSTS) 7th Design (StoTtos)
Silicon Nitride 1 45 40 50 48 45 40 28
Nichrome Nitride 1 - - - 3 3 3 -
Titanium oxide 1 - - - - - - 12
Titanium Nitride 1 35 12 30 30 25 8 30
Nichrome Nitride 2 - 3 - 3 - -
Silicon Nitride 2 40 15 45 43 45 15 -
Titanium oxide 2 - - - - - - 16
Titanium Nitride 2 - 20 - - - 20 -
Silicon Nitride 3 - 38 - - - 38 24

Minimum
layer stack 1st design 2nd design 3rd design 4th design 5th design 6th design 7th design
Silicon Nitride 1 20 30 25 35 35 35 20
Nichrome Nitride 1 - - - 0.2 1 0.2 -
Titanium oxide 1 - - - - - - 6
Titanium Nitride 1 20 8 20 20 15 3 25
Nichrome Nitride 2 - - 0.2 - 0.2 - -
Silicon Nitride 2 30 5 30 33 35 11 -
Titanium oxide 2 - - - - - - 10
Titanium Nitride 2 - 10 - - - 15
Silicon Nitride 3 - 27 - - - 30 15
The Invention is further described with the help of non-limiting examples:
Example 1:
Product layer stack: Si3N4/NiCrN/TiN/Si3N4 or Si3N4/TiN/NiCrN/Si3N4
Performance values pre-thermal treatment:
Product transmission 8 to 25 %
Reflection glass side varies from 3 to 10%
Reflection film side varies from 1 to 6%
Substrate: Dark Grey glass
Dark Grey glass Range 1 Range 2 Range 3 Exp 1 Exp2 Exp 3
Reflection Glass Y 3-10 2-8 4-7 5.0 5.2 5.5
L* 20 - 40 20-35 25 - 30 26.9 27.2 28.2
a* 1 to -3 0.5 to -2 0 to -1 -0.2 -0.4 -0.6
b* 1 to -7 -1 to -5 -1 to -2 -1.8 -1.8 -2.4
Transmission Y 8 - 25 10 - 19 10 - 15 16.6 13.2 10.8
L* 30 - 50 35 - 45 40 - 50 47.7 43.0 39.3
a* 1 to -5 0.5 to -4 0 to -4 -3.7 -4.0 -3.2
b* 1 to -8 -1 to -5 -1 to -2 -6.6 -6.8 -8.0
Reflection Film Y 1 - 5 2 - 6 2 - 4 2.3 2.3 4.0
L* 10 - 30 15 - 28 15 - 25 17.2 16.8 23.8
a* 10 to 25 10 to 20 10 to 15 14.2 19.0 11.1
b* 5 to 20 8 to 16 8 to 16 8.3 14.1 26.2

Example 2:
Product layer stack: Si3N4/NiCrN/TiN/Si3N4 or Si3N4/TiN/ NiCrN/ Si3N4
Performance values Pre-Thermal Treatment:
Product transmission 9 to 20 %
Reflection glass side varies from 8 to 25%
Reflection film side varies from 1 to 10%
Substrate: Green glass
Green glass Range 1 Range 2 Range 3 Exp 1 Exp2 Exp 3
Reflection Glass Y 9 to 20 10 to 18 12 to 16 16 11 10
L* 20 to 50 25 to 40 30 to 50 47 40 38
a* -3 to -10 -5 to -10 -6 to -10 -6.6 -4.6 -3.8
b* 0 to -3 -1 to -3 -1 to -2 -0.1 0.2 -0.8
Transmission Y 8 - 25 10 - 19 10 - 15 36 44 55
L* 30 - 50 35 - 45 40 - 50 67 72 79
a* 5 to -10 -5.5 to -9 -5.5 to -9 -7.5 -8.5 -8.1
b* 0 to -4 -1 to -3 -1 to -2 -3.0 -1.1 -0.1
Reflection Film Y 1 - 8 2 - 6 2 - 4 4 3 4
L* 10 - 30 15 - 28 15 - 25 25 21 23
a* 5 to 25 5 to 20 5 to 15 9.5 13.9 8.6
b* 5 to 25 5 to 25 5 to 25 20.8 10.6 6.5

Example 3:
Product layer stack: Si3N4/NiCrN/TiN/Si3N4 or Si3N4/TiN/ NiCrN/ Si3N4
Performance values Pre-Thermal Treatment:
Product transmission 30 to 70 %
Reflection glass side varies from 8 to 25%
Reflection film side varies from 1 to 15%
Substrate: Clear float glass
Clear glass Range 1 Range 2 Range 3 Exp 1 Exp2 Exp 3
Reflection Glass Y 9 to 20 10 to 18 12 to 16 19.3 13.5 11.9
L* 20 to 55 25 to 40 30 to 50 51.0 43.5 41.1
a* -0 to -4 -1 to -4 -2 to -3.5 -3.4 -2.1 -1.6
b* 0 to -3.5 -1 to -3 -1 to -2 -0.8 0.2 -1.0
Transmission Y 35 to 67 40 to 65 40 to 65 42.1 50.6 63.2
L* 60 to 85 70 to 85 70 to 80 71.0 76.5 83.6
a* -0 to -5.5 -1 to -5 -2 to -4.5 -4.0 -4.9 -4.1
b* 0 to -3.5 -1 to -3 -1 to -2 -3.4 -1.4 -0.4
Reflection Film Y 1 - 8 2 - 6 2 - 5 4.7 3.4 4.2
L* 10 - 30 15 - 28 15 - 25 25.8 21.7 24.4
a* 5 to 25 5 to 20 5 to 15 8.5 13.5 8.6

Example 4:
Blue products with different layer stacks designs: Designs are developed with materials of silicon nitride, Nickle chrome nitride, Titanium nitride
The table below shows the design of products having performance values Pre-Thermal Treatment as follows
• Transmission: 60 to 65 % range
• Reflection Glass side: 7 to 20 % range
• Reflection Film side: 3 to 15 % range
• Product Layer stack: STS, STNS, STSTS, SNTNS
• Colour shade: Blue
• Substrate: Clear float glass
Glass (nm) 6 6 6 6
1st Dielectric layer 1 59 58 48 60
2nd Functional layer 1_Bot - - - 1
3rd Functional layer 2_Bot 20 17 4 12
4th Dielectric layer 2 48 - 69 -
5th Functional layer 2_Top - - 8 -
6th Functional layer 1_Top - 1 - 1
7th Dielectric layer 3 - 54 24 59
Tr Y 63 61 59 63
Tr L* 83.1 82.2 81.0 83.1
Tr a* -5.0 -4.4 -1.4 -3.5
Tr b* 9.2 10.8 7.1 12.2
Rg Y 12 14 7 15
Rg L* 41.8 44.8 31.4 46.0
Rg a* -1.1 -2.3 -2.0 -2.0
Rg b* -20.9 -16.8 -17.3 -15.3
Rf Y 3 4 11 6
Rf L* 20.6 23.6 38.9 29.5
Rf a* 18.5 12.8 1.0 5.1
Rf b* -29.0 -38 -23.7 -39.6
g ISO 9050 0.50 0.50 0.54 0.53
g NFRC 0.48 0.48 0.52 0.51
g EN410 0.51 0.50 0.54 0.53
U Factor 4.9 4.9 5.1 4.8
Emissivity Normal 0.42 0.44 0.54 0.52
Emissivity Effective 0.43 0.45 0.54 0.51
CRI Tr 95 95 97 95
CRI Rg 70 76 70 79
CRI Rf 53 42 70 28
selectivity 1.2 1.2 1.1 1.2
The table below shows the design of products having performance values Pre-Thermal Treatment as follows:
• Transmission: 38 to 45% range
• Reflection Glass side: 10 to 20% range
• Reflection Film side: 3 to 10% range
• Product Layer stack: STS, STNS, STSTS, SNTNS
• Colour shade: Blue
• Substrate: Clear float glass
Glass (mm) 6 6 6 6
1st Dielectric layer 1 S 54 58 56 56
2nd Functional layer 1_Bot N - - - 1
3rd functional layer 2_Bot T 35 33 19 31
4th Dielectric layer 2 S 40 - 26 -
5th Functional layer 1_Top T - - 10 -
6th Functional layer 2_Top N - 1 - 1
7th Dielectric layer 3 S - 38 23 42
Tr Y 42 40 40 39
Tr L* 71.0 69.4 69.5 68.6
Tr a* -6.2 -6.0 -5.3 -5.7
Tr b* 8.2 6.1 7.0 7.5
Rg Y 16 16 10 17
Rg L* 46.7 46.5 37.2 48.0
Rg a* -1.8 -1.1 -2.1 -1.9
Rg b* -13.3 -16.6 -11.1 -13.2
Rf Y 4 5 4 4
Rf L* 22.6 26.1 23.1 23.1
Rf a* 25.9 25.2 24.4 25.8
Rf b* -11.3 11 -9.4 -12.1
g ISO 9050 0.36 0.35 0.37 0.34
g NFRC 0.34 0.33 0.35 0.32
g EN410 0.36 0.35 0.37 0.35
U Factor 4.7 4.6 4.8 4.6
Emissivity Normal 0.3 0.30 0.35 0.30
CRI Tr 93 93 94 93
CRI Rg 83 80 82 83
CRI Rf 29 20 32 31
selectivity 1.2 1.1 1.1 1.1

Example 5:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 55 %
Layer stack: STS
Substrate: Clear float Glas
55 percent: Blue shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 36 48 56 46 46 46 46 46 46 46
TiN / 1st Functional layer 23 23 23 13 25 33 23 23 23 23
T_Si3N4/ 2nd Dielectric layer 37 37 37 37 37 37 27 39 47 37
Tr Y 53.9 56.2 56.5 64.7 53.6 44.8 50.2 56.7 58.6 55.9
Tr L* 78.5 79.8 79.9 84.5 78.3 72.8 76.3 80.0 81.0 79.6
Tr a* -3.9 -5.2 -5.7 -2.9 -5.5 -6.7 -3.9 -5.2 -5.5 -5.0
Tr b* -2.3 0.2 3.1 -3.1 0.4 3.3 -2.7 0.4 5.0 -0.4
Rg Y 12.5 9.2 8.8 10.2 10.0 12.5 6.5 10.1 13.0 9.5
Rg L* 42.0 36.3 35.5 38.2 37.8 42.0 30.5 38.1 42.8 37.0
Rg a* -4.4 1.0 3.3 -2.6 0.4 0.9 0.6 -0.1 -0.8 0.0
Rg b* -2.8 -13.9 -23.5 -1.3 -12.1 -10.1 -10.5 -11.0 -7.0 -11.5
Rf Y 6.4 6.4 6.0 10.9 5.8 4.6 15.6 5.3 2.6 6.5
Rf L* 30.5 30.4 29.3 39.5 29.0 25.6 46.5 27.6 18.3 30.5
Rf a* 2.3 9.6 15.1 -0.4 11.1 21.1 1.0 10.5 19.8 8.3
Rf b* 21.7 24.4 20.7 21.5 23.2 12.4 22.2 17.9 -24.6 24.6
g ISO 9050 0.46 0.47 0.47 0.57 0.44 0.37 0.45 0.47 0.47 0.47
g NFRC 0.43 0.44 0.44 0.54 0.42 0.35 0.42 0.44 0.45 0.44
g EN410 0.46 0.47 0.47 0.57 0.45 0.38 0.45 0.47 0.47 0.47
U Factor 4.63 4.63 4.63 4.80 4.59 4.47 4.63 4.63 4.63 4.63
Emissivity Normal 0.38 0.38 0.38 0.52 0.36 0.30 0.38 0.38 0.39 0.38
CRI -Tr 93 93 93 94 92 91 92 93 95 93
CRI - Rg 88 82 70 91 85 90 86 85 90 84
CRI - Rf 70 53 42 80 49 26 79 53 58 56

Example 6:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 45 %
Layer stack: STS
Substrate: Clear float Glass
45 percent: Blue shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 15 27 35 25 25 25 25 25 25 25
TiN / 1st Functional layer 23 23 23 13 25 33 23 23 23 23
T_Si3N4/ 2nd Dielectric layer 22 22 22 22 22 22 12 24 32 22
Tr Y 42.6 44.2 45.3 54.5 42.0 34.9 39.8 44.8 48.4 43.9
Tr L* 71.3 72.4 73.2 78.7 71.0 65.8 69.3 72.8 75.2 72.2
Tr a* -3.4 -3.1 -3.1 -1.5 -3.5 -4.9 -3.5 -3.1 -3.0 -3.1
Tr b* 0.6 -1.3 -2.3 2.0 -1.5 -3.2 0.9 -1.3 -2.3 -0.9
Rg Y 13.0 9.7 7.6 10.9 10.6 12.5 7.3 11.1 14.5 10.3
Rg L* 42.8 37.4 33.0 39.4 38.9 41.9 32.4 39.7 45.0 38.4
Rg a* -1.4 -2.7 -2.5 -6.1 -1.7 1.0 2.0 -3.3 -5.5 -2.5
Rg b* -14.4 -10.6 -7.8 -13.6 -10.1 -3.5 -11.1 -10.9 -7.0 -11.4
Rf Y 14.9 18.0 19.7 18.1 17.6 17.5 25.3 15.9 9.4 17.5
Rf L* 45.5 49.5 51.5 49.6 48.9 48.9 57.3 46.8 36.8 48.9
Rf a* 2.2 0.0 -0.6 -2.9 1.0 4.2 1.4 0.0 -1.1 0.3
Rf b* -2.3 1.9 7.0 -6.4 3.0 12.8 -3.7 2.4 9.8 0.9
g ISO 9050 0.39 0.41 0.42 0.51 0.39 0.33 0.39 0.41 0.43 0.41
g NFRC 0.37 0.39 0.39 0.49 0.37 0.31 0.36 0.39 0.40 0.38
g EN410 0.40 0.42 0.43 0.51 0.40 0.34 0.39 0.42 0.43 0.41
U Factor 4.63 4.63 4.62 4.80 4.59 4.47 4.63 4.63 4.63 5.43
Emissivity-Normal 0.38 0.37 0.37 0.51 0.36 0.30 0.37 0.38 0.38 0.37
CRI -Tr 94 94 93 98 93 89 94 94 93 94
CRI - Rg 82 83 86 70 86 94 89 82 83 82
CRI - Rf 93 95 93 89 92 79 97 95 88 95

Example 7:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 45 %
Layer stack: STS
Substrate: Clear float Glass
45 percent: Blue shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4/ 1st Dielectric layer 80 92 100 89 89 89 89 89 89 89
TiN/ 1st Functional layer 25 25 25 15 27 35 25 25 25 25
T_Si3N4/2nd Dielectric layer 28 28 28 28 28 28 18 30 38 28
Tr Y 45.6 43.3 42.1 57.7 41.2 32.2 38.9 44.5 46.5 43.7
Tr L* 73.2 71.7 70.8 80.4 70.2 63.4 68.6 72.4 73.6 71.9
Tr a* -5.3 -4.2 -3.4 -4.5 -4.4 -4.5 -5.3 -4.1 -2.3 -4.4
Tr b* 5.0 4.4 2.8 5.9 4.3 2.6 2.6 5.2 7.2 4.7
Rg Y 12.7 16.9 19.1 8.6 18.0 24.4 12.9 17.2 22.1 16.2
Rg L* 42.3 48.1 50.8 35.1 49.4 56.5 42.7 48.5 54.2 47.3
Rg a* 2.3 -1.7 -3.8 5.8 -1.9 -4.1 6.2 -2.8 -9.0 -1.1
Rg b* -27.7 -22.2 -17.3 -32.5 -21.0 -11.8 -18.9 -23.0 -18.3 -23.3
Rf Y 9.4 7.7 7.0 8.4 7.9 7.6 17.5 6.5 2.8 7.9
Rf L* 36.8 33.3 31.7 34.7 33.7 33.0 48.9 30.5 19.4 33.9
Rf a* 21.2 24.5 23.9 20.2 25.0 27.6 16.8 25.8 24.9 24.3
Rf b* 26.1 11.6 3.4 4.3 16.0 24.3 16.2 11.7 -7.4 13.9
g ISO 9050 0.41 0.40 0.40 0.51 0.38 0.32 0.38 0.40 0.41 0.40
g NFRC 0.39 0.38 0.38 0.49 0.36 0.30 0.36 0.38 0.40 0.38
g EN410 0.41 0.40 0.40 0.51 0.39 0.32 0.38 0.41 0.42 0.40
U Factor 4.58 4.58 4.58 4.75 4.55 4.43 4.58 4.58 4.58 4.79
Emissivity-Normal 0.35 0.35 0.34 0.46 0.33 0.28 0.34 0.35 0.35 0.35
CRI -Tr 94 94 95 95 94 92 93 95 96 94
CRI - Rg 67 72 77 57 74 84 85 70 68 71
CRI - Rf 34 31 32 48 27 16 58 24 2 31

Example 8:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 30 %
Layer stack: STS
Substrate: Clear float Glass
30 percent- Blue shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4/ 1st Dielectric layer 84 92 104 94 94 94 94 94 94 94
TiN/ 1st Functional layer 35 35 35 25 33 45 35 35 35 35
T_Si3N4/2nd Dielectric layer 28 28 28 28 28 28 19 27 39 28
Tr Y 32.5 31.2 30.0 42.3 32.7 21.5 27.4 30.5 33.2 31.0
Tr L* 63.8 62.8 61.8 71.1 64.0 53.6 59.5 62.1 64.2 62.5
Tr a* -6.0 -5.6 -5.1 -5.1 -5.4 -5.9 -6.3 -5.7 -3.5 -5.5
Tr b* 1.4 0.2 -2.5 2.3 0.2 -2.5 -1.8 -0.5 2.2 -0.2
Rg Y 21.6 24.4 27.0 16.7 23.7 31.5 21.8 24.4 30.4 25.0
Rg L* 53.6 56.5 59.0 47.9 55.8 62.9 53.8 56.5 62.0 57.1
Rg a* -0.6 -1.5 -2.3 0.4 -1.4 -2.9 3.3 -0.9 -7.2 -1.7
Rg b* -12.8 -9.3 -2.7 -18.3 -9.9 2.4 -6.4 -8.3 -3.1 -8.2
Rf Y 10.2 9.3 8.4 8.8 9.1 9.1 19.1 10.5 3.3 9.1
Rf L* 38.2 36.6 34.7 35.5 36.1 36.2 50.8 38.7 21.1 36.2
Rf a* 24.5 26.1 26.1 23.7 25.9 28.3 18.5 25.0 27.9 26.3
Rf b* 36.9 30.1 20.7 17.1 26.4 39.3 21.5 27.2 11.9 28.3
g ISO 9050 0.32 0.31 0.31 0.39 0.32 0.25 0.30 0.31 0.32 0.31
g NFRC 0.30 0.29 0.29 0.37 0.30 0.23 0.28 0.29 0.30 0.29
g EN410 0.32 0.31 0.31 0.39 0.32 0.25 0.30 0.31 0.32 0.31
U Factor 4.37 4.37 4.37 4.53 4.40 4.23 4.37 4.37 4.37 4.60
Emissivity-Normal 0.26 0.26 0.26 0.32 0.27 0.22 0.26 0.26 0.26 0.26
CRI -Tr 90 90 88 93 90 86 87 89 94 90
CRI - Rg 87 90 95 80 89 98 95 92 87 91
CRI - Rf 24 21 23 32 23 13 53 27 0.5 21

Example 9:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 55 %
Layer stack: STS
Substrate: Clear float Glass
55 percent-Green shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 17 29 37 27 27 27 27 27 27 27
TiN / 1st Functional layer 21 21 21 11 23 31 21 21 21 21
T_Si3N4/ 2nd Dielectric layer 38 38 38 38 38 38 28 40 48 38
Tr Y 50.2 53.5 55.7 61.8 51.5 44.0 49.0 53.7 55.2 53.0
Tr L* 76.2 78.3 79.5 82.8 77.1 72.3 75.5 78.4 79.2 78.0
Tr a* -2.4 -2.9 -3.7 -1.0 -3.2 -5.0 -2.6 -3.0 -3.5 -2.8
Tr b* -0.5 -2.4 -2.4 -1.4 -2.2 -1.3 -1.9 -2.0 0.2 -2.3
Rg Y 20.4 15.5 12.2 17.2 16.3 17.5 12.0 17.1 19.7 16.2
Rg L* 52.2 46.3 41.6 48.5 47.4 48.9 41.2 48.3 51.5 47.2
Rg a* -6.9 -6.5 -4.5 -7.0 -6.3 -4.3 -5.3 -6.7 -6.1 -6.7
Rg b* -6.2 -2.3 -3.0 -4.2 -1.7 4.6 -9.4 -0.6 8.3 -2.7
Rf Y 5.6 6.4 6.7 13.1 5.7 3.6 13.1 5.2 2.9 6.4
Rf L* 28.3 30.5 31.1 42.9 28.5 22.3 43.0 27.2 19.6 30.3
Rf a* -4.4 -1.9 1.6 -5.7 -0.7 11.4 -1.7 -2.0 3.0 -2.4
Rf b* 4.6 15.3 21.2 5.1 15.5 17.0 5.1 13.6 -7.2 13.9
g ISO 9050 0.44 0.46 0.47 0.56 0.44 0.38 0.44 0.46 0.46 0.46
g NFRC 0.41 0.43 0.45 0.54 0.42 0.35 0.42 0.43 0.44 0.43
g EN410 0.44 0.47 0.48 0.57 0.45 0.38 0.45 0.46 0.47 0.46
U Factor 4.66 4.66 4.66 4.84 4.63 4.50 4.66 4.66 4.66 4.80
Emissivity-Normal 0.40 0.40 0.40 0.56 0.38 0.32 0.40 0.40 0.41 0.40
CRI -Tr 95 94 93 97 94 91 94 94 95 94
CRI - Rg 83 85 87 82 87 96 80 87 93 85
CRI - Rf 95 84 73 92 80 40 95 85 91 86

Example 10:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 45 %
Layer stack: STS
Substrate: Clear float Glass
45 percent-Green shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 11 23 31 18 18 18 18 18 18 18
TiN / 1st Functional layer 26 26 26 16 28 36 26 26 26 26
T_Si3N4/ 2nd Dielectric layer 32 32 32 32 32 32 22 34 42 32
Tr Y 42.9 45.4 47.3 54.0 42.4 35.2 40.3 45.0 46.9 44.3
Tr L* 71.5 73.3 74.5 78.4 71.2 66.0 69.7 72.9 74.2 72.5
Tr a* -3.4 -3.4 -3.7 -1.7 -3.7 -5.3 -3.7 -3.3 -3.3 -3.4
Tr b* 0.0 -2.2 -3.0 1.0 -1.6 -2.2 -0.4 -1.3 -0.4 -1.3
Rg Y 20.5 16.0 12.7 16.1 18.5 20.6 13.1 19.1 22.9 18.0
Rg L* 52.4 47.0 42.3 47.1 50.2 52.5 43.0 50.8 55.0 49.5
Rg a* -4.4 -4.9 -4.2 -6.5 -4.5 -3.0 -0.9 -5.4 -6.8 -4.8
Rg b* -9.8 -6.2 -4.5 -13.1 -6.0 2.5 -12.1 -6.2 1.9 -7.8
Rf Y 6.7 8.5 9.5 10.9 7.4 6.3 15.8 6.4 2.6 7.8
Rf L* 31.1 35.0 37.0 39.5 32.6 30.2 46.7 30.3 18.6 33.5
Rf a* 2.6 0.8 1.1 -4.4 2.9 10.8 2.7 0.9 0.2 1.2
Rf b* 3.6 11.1 17.8 -3.3 10.7 24.5 0.6 9.0 3.3 7.6
g ISO 9050 0.38 0.40 0.41 0.49 0.38 0.32 0.38 0.39 0.40 0.39
g NFRC 0.36 0.38 0.39 0.46 0.35 0.30 0.35 0.37 0.38 0.37
g EN410 0.38 0.41 0.42 0.49 0.38 0.32 0.38 0.40 0.41 0.40
U Factor 4.59 4.58 4.58 4.76 4.55 4.43 4.59 4.59 4.58 4.79
Emissivity-Normal 0.36 0.35 0.35 0.47 0.34 0.29 0.35 0.36 0.36 0.36
CRI -Tr 90 90 90 92 89 87 89 90 91 90
CRI - Rg 94 96 97 87 97 96 95 96 97 96
CRI - Rf 52 53 52 80 47 29 71 50 33 53

Example 11:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 30 %
Layer stack: STS
Substrate: Clear float Glass
30 percent- Green shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 81 93 101 91 91 91 91 91 91 91
TiN / 1st Functional layer 37 37 37 27 39 47 37 37 37 37
T_Si3N4/ 2nd Dielectric layer 33 33 33 33 33 33 23 35 43 33
Tr Y 32.7 30.7 29.8 42.3 29.0 22.0 28.0 31.3 31.5 30.9
Tr L* 63.8 62.2 61.5 70.9 60.7 54.0 59.9 62.6 62.8 62.4
Tr a* -4.6 -3.6 -3.2 -3.5 -3.8 -4.2 -5.2 -3.3 -1.5 -3.7
Tr b* 5.3 2.1 -0.7 5.0 2.3 1.0 0.7 3.2 5.2 2.7
Rg Y 24.7 28.9 30.5 20.7 29.5 33.1 23.8 29.4 33.3 28.4
Rg L* 56.8 60.7 62.1 52.7 61.3 64.2 55.9 61.1 64.4 60.2
Rg a* -5.7 -7.1 -7.6 -5.6 -7.0 -6.9 -1.1 -7.9 -10.4 -7.0
Rg b* -12.4 -4.9 1.0 -18.8 -3.8 5.6 -9.6 -4.8 2.8 -6.3
Rf Y 5.2 4.3 3.9 4.8 4.4 4.2 13.0 3.5 3.4 4.5
Rf L* 27.3 24.8 23.5 26.2 25.0 24.3 42.8 22.1 21.4 25.2
Rf a* 31.3 31.4 29.7 27.9 32.2 34.2 22.7 32.2 14.9 31.6
Rf b* 25.3 21.0 19.3 9.2 23.5 26.9 21.9 15.4 -10.9 21.6
g ISO 9050 0.31 0.31 0.30 0.39 0.29 0.25 0.30 0.31 0.31 0.31
g NFRC 0.30 0.29 0.29 0.37 0.28 0.23 0.28 0.29 0.30 0.29
g EN410 0.32 0.31 0.31 0.39 0.30 0.25 0.30 0.31 0.31 0.31
U Factor 4.41 4.41 4.40 4.55 4.38 4.29 4.41 4.41 4.41 4.51
Emissivity-Normal 0.28 0.27 0.27 0.33 0.27 0.24 0.27 0.28 0.28 0.27
CRI -Tr 93 93 92 95 93 91 90 94 97 93
CRI - Rg 81 86 90 73 88 94 90 85 86 86
CRI - Rf -1 -3 -3 14 -6 -13 39 -4 28 -3
Example 12:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 70 %
Layer stack: STS
Substrate: Clear float Glass
70 percent-Neutral shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 37 49 57 47 47 55 47 47 47 47
TiN / 1st Functional layer 12 12 12 8 16 12 12 12 12 12
T_Si3N4/ 2nd Dielectric layer 44 44 44 44 44 44 34 46 54 44
Tr Y 65.6 69.2 70.7 71.8 65.0 70.4 63.7 69.1 70.7 68.5
Tr L* 84.9 86.7 87.3 88.0 84.5 87.2 83.9 86.6 87.3 86.4
Tr a* -2.5 -4.1 -4.9 -3.0 -4.5 -4.8 -2.4 -4.0 -4.7 -3.8
Tr b* -2.8 -0.6 2.4 -3.1 0.5 1.6 -3.4 -0.7 3.3 -1.4
Rg Y 14.9 10.6 8.9 12.9 11.0 9.2 9.9 11.5 12.6 11.3
Rg L* 45.5 38.9 35.9 42.5 39.6 36.4 37.6 40.5 42.1 40.1
Rg a* -4.9 0.9 4.8 -0.6 -0.4 4.0 -3.3 -0.1 1.5 -0.5
Rg b* 3.6 -4.4 -16.1 5.7 -6.4 -13.1 0.0 -1.6 -1.6 -1.5
Rf Y 8.5 6.9 5.7 10.8 4.9 6.0 13.5 6.6 4.8 7.2
Rf L* 35.0 31.5 28.7 39.3 26.4 29.4 43.5 30.8 26.0 32.3
Rf a* -1.4 6.8 13.1 2.2 9.4 11.6 -1.7 6.4 13.3 4.9
Rf b* 16.7 12.9 2.7 19.4 5.8 5.6 18.9 10.8 -16.1 15.0
g ISO 9050 0.57 0.58 0.59 0.63 0.54 0.59 0.57 0.58 0.59 0.58
g NFRC 0.55 0.56 0.57 0.61 0.51 0.56 0.54 0.56 0.57 0.56
g EN410 0.58 0.59 0.59 0.63 0.54 0.59 0.57 0.59 0.59 0.59
U Factor 4.81 4.81 4.81 4.89 4.74 4.81 4.81 4.81 4.81 5.00
Emissivity-Normal 0.54 0.53 0.53 0.63 0.46 0.53 0.53 0.53 0.54 0.53
CRI -Tr 95 94 95 95 94 95 95 95 96 94
CRI - Rg 91 95 84 95 90 88 90 95 99 95
CRI - Rf 85 71 65 78 68 66 85 74 84 74

Example 13:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 65 %
Layer stack: STS
Substrate: Clear float Glass
65 percent-Neutral shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 34 46 54 44 44 44 44 44 44 44
TiN / 1st Functional layer 16 16 16 10 19 25 16 16 16 16
T_Si3N4/ 2nd Dielectric layer 43 43 43 43 43 43 33 45 53 43
Tr Y 61.6 65.1 66.5 69.1 61.6 55.3 59.7 65.1 66.3 64.6
Tr L* 82.8 84.6 85.2 86.7 82.8 79.2 81.8 84.6 85.1 84.3
Tr a* -2.7 -4.2 -5.1 -2.8 -4.6 -5.6 -2.7 -4.2 -4.8 -4.0
Tr b* -2.3 -0.4 2.5 -3.1 0.4 3.1 -3.2 -0.3 3.8 -1.0
Rg Y 15.3 10.9 9.3 12.8 11.6 12.7 9.1 11.9 13.5 11.5
Rg L* 46.1 39.4 36.5 42.5 40.6 42.3 36.2 41.0 43.5 40.4
Rg a* -5.9 -0.8 2.8 -2.2 -1.6 -1.1 -3.8 -1.6 -0.2 -1.9
Rg b* 1.9 -5.3 -16.3 3.9 -5.3 -6.4 -3.8 -2.7 0.0 -3.0
Rf Y 6.6 5.7 4.9 10.0 4.4 2.8 12.6 5.2 3.7 5.9
Rf L* 30.9 28.6 26.5 37.8 24.8 19.4 42.1 27.3 22.7 29.0
Rf a* -1.8 7.0 13.5 0.8 9.6 18.9 -1.6 7.0 14.0 5.3
Rf b* 15.0 12.0 3.2 19.4 6.0 -11.1 19.0 8.0 -22.4 13.5
g ISO 9050 0.53 0.54 0.55 0.61 0.51 0.45 0.53 0.54 0.54 0.54
g NFRC 0.50 0.52 0.52 0.58 0.48 0.42 0.50 0.52 0.52 0.52
g EN410 0.53 0.55 0.55 0.61 0.51 0.45 0.53 0.55 0.55 0.54
U Factor 4.75 4.75 4.75 4.86 4.69 4.59 4.75 4.75 4.75 4.75
Emissivity-Normal 0.47 0.47 0.47 0.58 0.43 0.36 0.47 0.47 0.48 0.47
CRI -Tr 95 94 95 95 94 93 94 94 96 94
CRI - Rg 89 91 81 95 90 91 85 92 97 91
CRI - Rf 86 70 61 80 66 53 84 73 78 72

Example 14:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 55 %
Layer stack: STS
Substrate: Clear float Glass
55 percent-Neutral shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 35 40 43 39 39 39 39 39 39 39
TiN / 1st Functional layer 25 25 25 20 26 30 25 25 25 25
T_Si3N4/ 2nd Dielectric layer 41 41 41 41 41 41 35 39 45 41
Tr Y 51.2 52.3 52.8 57.5 51.2 46.6 49.7 51.3 52.8 52.1
Tr L* 76.9 77.5 77.8 80.6 76.9 74.0 76.0 77.0 77.8 77.4
Tr a* -4.9 -5.2 -5.4 -4.1 -5.3 -6.0 -5.0 -5.1 -5.2 -5.2
Tr b* -1.3 -0.6 0.1 -1.6 -0.6 0.2 -2.5 -1.5 0.6 -0.8
Rg Y 14.9 13.3 12.4 12.5 13.8 15.0 11.0 12.6 15.0 13.6
Rg L* 45.4 43.2 41.9 42.0 43.9 45.6 39.6 42.1 45.6 43.6
Rg a* -3.2 -2.1 -1.3 -3.5 -2.1 -1.2 -1.3 -2.0 -2.5 -2.3
Rg b* -0.1 -2.6 -5.1 -3.1 -1.6 0.6 -5.8 -3.6 0.9 -2.0
Rf Y 3.2 3.4 3.6 4.7 3.3 3.0 7.5 4.6 2.2 3.4
Rf L* 20.9 21.7 22.1 25.9 21.1 20.0 32.8 25.7 16.5 21.5
Rf a* 9.2 11.5 13.1 3.5 12.3 17.9 6.0 8.8 14.2 11.0
Rf b* 12.5 12.1 11.4 15.7 11.2 5.4 22.9 20.4 -6.6 12.3
g ISO 9050 0.43 0.43 0.44 0.48 0.42 0.39 0.42 0.43 0.43 0.43
g NFRC 0.40 0.41 0.41 0.46 0.40 0.36 0.40 0.40 0.41 0.41
g EN410 0.43 0.44 0.44 0.49 0.43 0.39 0.43 0.43 0.44 0.44
U Factor 4.33 4.33 4.33 4.43 4.31 4.25 4.33 4.33 4.33 4.35
Emissivity-Normal 0.33 0.33 0.33 0.38 0.32 0.29 0.33 0.33 0.33 0.33
CRI -Tr 92 92 92 93 92 91 91 91 93 92
CRI - Rg 94 94 92 89 95 98 92 93 96 94
CRI - Rf 50 46 43 70 43 32 62 51 51 46

Example 15:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 45 %
Layer stack: STS
Substrate: Clear float Glass
45 percent-Neutral shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 20 27 32 26 26 26 26 26 26 26
TiN / 1st Functional layer 29 29 29 23 30 35 29 29 29 29
T_Si3N4/ 2nd Dielectric layer 35 35 35 35 35 35 29 36 41 35
Tr Y 42.0 43.7 44.8 49.2 42.0 37.2 40.9 43.7 45.0 43.4
Tr L* 71.0 72.2 72.9 75.7 71.0 67.6 70.3 72.2 73.0 72.0
Tr a* -4.9 -5.1 -5.4 -3.9 -5.4 -6.3 -5.1 -5.1 -5.0 -5.1
Tr b* -2.3 -2.8 -2.8 -2.1 -2.8 -2.8 -3.2 -2.6 -1.5 -2.7
Rg Y 19.3 16.2 14.3 15.2 17.2 18.6 14.0 17.2 19.3 16.7
Rg L* 51.0 47.3 44.7 45.9 48.5 50.2 44.2 48.5 51.1 47.9
Rg a* -2.9 -2.3 -1.7 -4.0 -2.1 -1.0 -0.2 -2.7 -3.6 -2.5
Rg b* -2.3 -1.3 -1.6 -5.9 -0.1 4.7 -5.1 -0.6 3.8 -1.4
Rf Y 4.9 5.7 6.2 6.6 5.4 5.1 10.7 4.9 2.4 5.6
Rf L* 26.5 28.6 29.8 30.9 27.9 27.1 39.1 26.4 17.4 28.3
Rf a* 8.8 8.4 8.7 1.9 10.1 15.5 6.3 8.9 12.1 8.4
Rf b* 14.7 19.6 23.0 9.6 21.1 28.6 13.2 19.0 10.0 18.7
g ISO 9050 0.36 0.38 0.38 0.43 0.36 0.33 0.37 0.38 0.38 0.38
g NFRC 0.34 0.35 0.36 0.40 0.34 0.30 0.34 0.35 0.36 0.35
g EN410 0.37 0.38 0.39 0.43 0.37 0.33 0.37 0.38 0.39 0.38
U Factor 4.47 4.47 4.47 4.57 4.45 4.37 4.47 4.47 4.47 4.47
Emissivity-Normal 0.30 0.30 0.30 0.35 0.29 0.27 0.30 0.30 0.30 0.30
CRI -Tr 90 90 90 92 89 87 89 90 91 90
CRI - Rg 94 96 97 87 97 96 95 96 97 96
CRI - Rf 52 53 52 80 47 29 71 50 33 53

Example 16:
Thickness range and its performance values Pre-Thermal Treatment:
Product transmission 30 %
Layer stack: STS
Substrate: Clear float Glass
30 percent-Neutral shade
Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 Exp-7 Exp-8 Exp-9 F1
B_Si3N4 / 1st Dielectric layer 85 95 110 103 103 103 103 103 103 103
TiN / 1st Functional layer 36 36 36 20 30 45 36 36 36 36
T_Si3N4/ 2nd Dielectric layer 26 26 26 26 26 26 10 22 40 26
Tr Y 30.6 29.3 28.3 47.2 34.4 20.5 22.8 27.1 31.2 28.6
Tr L* 62.2 61.1 60.4 74.3 65.3 52.6 55.1 59.2 62.7 60.5
Tr a* -6.2 -5.8 -5.3 -4.6 -5.2 -6.0 -6.4 -5.9 -3.1 -5.5
Tr b* 0.5 -1.0 -4.6 2.5 -1.0 -5.1 -4.1 -3.3 -0.5 -2.8
Rg Y 21.9 25.0 27.2 13.5 22.2 32.2 22.6 24.9 33.3 26.6
Rg L* 53.9 57.1 59.1 43.5 54.3 63.5 54.7 57.0 64.4 58.6
Rg a* 0.3 -0.7 -1.3 1.7 -0.4 -2.1 5.7 1.2 -7.5 -1.2
Rg b* -11.6 -7.0 1.6 -19.4 -8.5 6.9 3.7 -2.5 4.2 -2.8
Rf Y 12.1 11.0 10.0 9.0 10.0 10.6 28.1 14.9 2.7 10.4
Rf L* 41.4 39.6 37.9 36.0 37.8 39.0 59.9 45.6 18.8 38.5
Rf a* 23.1 24.7 23.6 21.6 23.9 25.7 14.5 21.3 26.2 24.7
Rf b* 34.8 26.8 16.8 2.9 14.5 31.6 12.8 17.9 9.3 21.0
g ISO 9050 0.31 0.30 0.30 0.44 0.34 0.24 0.27 0.29 0.31 0.30
g NFRC 0.29 0.28 0.28 0.41 0.32 0.23 0.25 0.27 0.29 0.28
g EN410 0.31 0.30 0.30 0.44 0.34 0.25 0.28 0.29 0.31 0.30
U Factor 4.36 4.36 4.36 4.62 4.44 4.23 4.36 4.36 4.36 4.59
Emissivity-Normal 0.25 0.25 0.25 0.36 0.28 0.22 0.25 0.25 0.26 0.25
CRI -Tr 89 89 86 94 90 83 85 86 93 88
CRI - Rg 89 93 98 79 92 96 88 97 92 97
CRI - Rf 31 29 33 45 35 24 69 46 -5 31

Example 17:
Taber Test results
The durability of the coating stack was evaluated using a Taber instrument (Instrument Model: 5135 Abraser) with 300 rotations, applied to various products with transmission values ranging from 45% to 65% on clear glass. According to the EN1096 standard, a product passes the durability test if the difference in transmission Y values does not exceed ±2%. The data from the table indicates that all the developed products successfully met this criterion, demonstrating the robustness and durability of the coatings applied.

Pre-Thermal Treatment
Product Name Condition L* a* b* X Y Z Diff.
65% with Taber 83.93 -4.39 -0.43 58.77 63.93 69.12 -0.18
Without Taber 84.02 -4.38 0.22 58.95 64.11 68.53
55% with Taber 76.51 -4.66 -1.64 46.42 50.72 56.13 -0.02
Without Taber 76.52 -4.8 -1.1 46.38 50.74 55.59
45% with Taber 70.96 -4.11 -3.45 38.64 42.12 48.4 -0.38
Without Taber 71.22 -4.08 -3.11 39 42.5 48.51

Post Thermal treatment
Product Name Condition L* a* b* X Y Z Diff.
65% with Taber 85.34 -3.85 -0.58 61.56 66.68 72.29 -0.03
Without Taber 85.36 -3.82 -0.07 61.61 66.71 71.69
55% with Taber 78.97 -4.6 -1.5 50.29 54.87 60.52 0.17
Without Taber 78.87 -4.5 -0.89 50.16 54.7 59.66
45% with Taber 73.84 -4.6 -2.19 42.5 46.46 52.01 -0.38
Without Taber 74.09 -4.5 -2 42.88 46.84 52.24

Figure 4 shows comprehensive Analysis of Transmission, Selectivity, and Energy Performance from the spectral curves which are measured from UV-Visible Spectrophotometer.
The spectral graph in Figure 4 show a detailed insights into the transmission verses wavelength characteristics of various coated glass products (30_Tr, 45_Tr, 55_Tr, 65_Tr, 70_Tr) compared to standard uncoated glass in the range 250 to 2500 nm.
Transmission Characteristics:
• Uncoated Glass (Green Line):
The uncoated glass shows consistently high transmission across the entire spectrum, with values approaching 90% in the visible and near-infrared regions. This high transmission is typical of uncoated glass, which allows a significant amount of both visible and infrared light to pass through.
• Coated Products:
All coated products exhibit lower transmission across the spectrum compared to uncoated glass. This is particularly evident in the infrared (IR) heat wavelength range, from 750 to 2500 nm, where transmission is substantially reduced. This indicates that these coatings are effective at controlling heat gain by blocking a significant portion of IR radiation.

The products labeled 70_Tr and 65_Tr have the highest transmission in the visible range (around 450 nm), making them ideal for applications where natural light is essential. In contrast, products like 30_Tr and 45_Tr have lower overall transmission, which is beneficial for reducing solar heat gain in hotter climates.

Selectivity:
• High Selectivity:
The coated products demonstrate high selectivity, particularly in balancing visible light transmission with infrared reflection. This is evident from the sharp peak in the visible region and the subsequent decline in transmission as the wavelength increases, particularly beyond 750 nm, where the IR heat range begins.

Selective coatings like these allow natural light to penetrate while blocking a significant portion of IR radiation (750–2500 nm), thereby enhancing energy efficiency by minimizing unwanted heat gain.
Energy Performance and Emissivity:
• Emissivity Variations:
The emissivity of these coatings varies between 0.23 and 0.42. Lower emissivity values, such as 0.23, indicate a higher capacity to reduce heat loss by emitting less infrared radiation, making the glass more effective at insulating buildings.

Products with higher emissivity (closer to 0.42) still provide good energy performance but may allow slightly more heat loss compared to those with lower emissivity.

Performance Implications:
Low Emissivity, High Transmission (e.g., 70_Tr): These products are ideal for regions where maximizing daylight is crucial without compromising too much on energy efficiency. The lower infrared transmission in the IR heat range (750–2500 nm) further contributes to reducing solar heat gain.
Moderate Transmission, Moderate Emissivity (e.g., 45_Tr, 55_Tr): These products are balanced for applications where controlling both heat gain and loss is important. Their moderate transmission and emissivity values make them versatile for a wide range of climates.
High Durability: As previously mentioned, all these products have also passed durability tests, confirming that they maintain their performance over time under standard conditions.
By integrating the data of Figure 4, from spectral graphs and considering the emissivity values, it's clear that the coated products offer superior selectivity and energy performance compared to uncoated glass. These coatings provide tailored solutions for energy-efficient glazing, ensuring that buildings can optimize natural light while minimizing both heat gain and loss. The reduction of IR transmission in the 750 to 2500 nm range, combined with controlled emissivity, makes these products highly effective for various applications, from cold climates needing better insulation to warm regions requiring efficient solar control.
Example 18:
Images of FE-SEM (Field Emission Scanning Electron Microscopy)
The provided EDAX data and FESEM images offer a comprehensive understanding of the coating defects observed on the glass surface. The results are shown in Figure 5, which discloses the FESEM image of cluster defects on the surface of the coatings and FESEM image of pin hole defects on the surface of the coatings.
1. Identification of Contaminants:
• EDAX Analysis:
o The EDAX analysis reveals a significant presence of iron (Fe) with a weight percentage of 6.1% and an atomic percentage of 2.1%. This finding is crucial as it indicates that Fe particles are a major contaminant within the coating.
o Other elements like silicon (Si), oxygen (O), and carbon (C) are also present in notable amounts, which might be components of the base material or the result of environmental exposure.
o Nickle (Ni), Nitrogen (N), Titanium (Ti), are also present in smaller quantities, indicating potential components of the base material or the coating itself.
2. Surface Damage and Defect Formation:
• FESEM Images:
o The FESEM images display a series of craters and pitting on the coating surface, which are directly linked to the presence of Fe particles as identified in the EDAX analysis. These defects suggest that the Fe particles have impacted the surface, causing material displacement and creating visible craters.
o The repetitive nature of these defects across multiple areas indicates a recurring issue during the coating process, likely due to Fe contamination from the chamber walls or other sources within the production environment.

3. Implications for Coating Integrity:
• The combination of EDAX data and FESEM imagery highlights the detrimental effect of Fe contamination on the coating's quality. The presence of Fe particles not only causes physical defects but also introduces impurities that compromise the mechanical and optical properties of the coating.
• The defects observed in the FESEM images can lead to localized stress concentrations, reducing the overall durability of the coating. Additionally, the craters and pitting can scatter light, degrading the optical performance of the coated glass.
4. Corrective Measures:
• Understanding the material composition through EDAX and visualizing the resulting surface damage via FESEM is crucial for identifying the source of contamination. The Fe particles likely originate from the chamber walls or other internal components, suggesting a need for stricter contamination control and maintenance protocols.
• Implementing these corrective measures will be essential to prevent similar defects in future production runs, ensuring the production of high-quality, defect-free coatings.
The combined EDAX and FESEM analysis provides a clear correlation between the presence of Fe particles and the observed defects on the coating surface. Addressing this contamination issue is critical for improving the coating process and enhancing the durability and optical performance of the final product.

Figure 5 shows FESEM images of coating defects caused by Fe particle contamination, confirmed by EDAX analysis. The craters and pitting observed on the coated surface indicate significant damage from Fe particles, which comprise 6.1% of the sample's weight. This contamination affects both the mechanical integrity and optical performance of the coating
Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
The foregoing description of embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from the practice of the invention. The embodiments were chosen and described in order to explain the principals of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. , Claims:We Claim:
1. An enhanced solar control coatings for glass facades comprising:
a) a glass substrate (100) with at least two outer surfaces in which a first outer surface is incident to solar light and a second outer/inner surface on which a layer of coating is applied;
b) a first dielectric layer (101) applied on the second outer surface of the glass substrate (100) comprises silicon nitride (Si3N4);
c) a first functional layer (102) comprises titanium nitride (TiN) deposited over the first dielectric layer (101);
d) a second dielectric layer (104) comprises silicon nitride (Si3N4) deposited over the second functional layer (103);
e) blocking layer of Nichrome nitride, positioned above and/or below the first functional layer;
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).
2. The coating as claimed in claim 1, wherein the glass substrate (100) comprises a clear float glass substrate or a tinted glass substrate comprising the thickness ranging from 2mm to 12 mm.
3. The coating as claimed in claim 1, comprises a first blocking layer of Nichrome nitride positioned above the first functional layer and a second blocking layer of Nichrome nitride positioned below the first functional layer.
4. The coating as claimed in claim 3, wherein first blocking layer of Nichrome nitride positioned above the first functional layer and the second blocking layer of Nichrome nitride positioned below the first functional layer is replaced by a third dielectric layer of Titanium oxide and fourth dielectric layer of Titanium oxide respectively.
5. The coating as claimed in claim 1, comprises the top layers of atleast a second functional layer comprising Titanium Nitride placed over said first dielectric layer and a third dielectric layer of silicon nitride over said layer of Titanium Nitride.
6. The coating as claimed in claim 1, comprises the top layers of atleast a second functional layer comprising Titanium Nitride placed over said first dielectric layer followed by a blocking layer of Nichrome nitride and a third dielectric layer of silicon nitride over said layer of Titanium Nitride.
7. The coating as claimed in claim 1, wherein the tinted glass comprises glasses comprising shades of green or blue or dark grey or bronze is configured to improve the control of solar UV rays and infrared transmission.
8. The coating as claimed in claim 1, wherein the emissivity of the coating ranges from 0.25 to 0.42.
9. The coating as claimed in claim 1, wherein the selectivity of the coating ranges from 1.0 to 1.5 for both monolithic glass units (MGU) and integrated glass units (IGU).
10. The coating as claimed in claim 1, wherein the thickness of the layers for 45% transmission, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness ranging from 26 to 103nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness ranging from 3 to 35nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness ranging from 5 to 45nm;
d) first and/or second blocking layers of Nichrome nitride present in the thickness ranging from 1 to 3nm;
e) third dielectric layer of Titanium oxide present in the thickness ranging from 6 to 12nm and fourth dielectric layer of Titanium oxide is present in the thickness range of 10 to 16nm respectively;
f) top layers of atleast a second functional layer comprising Titanium Nitride placed over said first dielectric layer present in the thickness ranging from 10 to 20nm and a third dielectric layer of silicon nitride over said layer of Titanium Nitride present in the thickness ranging from 27 to 38nm;
g) the top layers of atleast a second functional layer comprising Titanium Nitride present in the thickness ranging from 10 to 20nm placed over said first dielectric layer followed by a blocking layer of Nichrome nitride present in the thickness ranging from 1 to 3nm and a third dielectric layer of silicon nitride over said layer of Titanium Nitride present in the thickness ranging from 15 to 38nm.
11. The coating as claimed in claim 1, comprises 1st dielectric layer present in the thickness of 26nm, 2nd functional layer in the thickness of 26 to 30nm while the third dielectric layer in the thickness of 34nm.
12. The coating as claimed in claim 1, comprises 1st dielectric layer present in the thickness of 35 to 38nm, 2nd functional layer in the thickness of 10nm, third dielectric layer in the thickness of 7 to 13nm, fourth functional layer in the thickness of 14 to 18nm, 5th dielectric layer in the thickness of 28nm to 36nm.
13. The coating as claimed in claim 1, comprises 1st dielectric layer present in the thickness of 29 to 48nm, 2nd functional layer in the thickness of 23 to 28nm, third blocking layer in the thickness of 1nm, fourth dielectric layer in the thickness of 34 to 40nm.
14. The coating as claimed in claim 1, comprises 1st dielectric layer present in the thickness of 37 to 45nm, 2nd blocking layer in the thickness of 1nm, third functional layer in the thickness of 26nm to 27nm, fourth dielectric layer in the thickness of 37 to 41nm.
15. The coating as claimed in claim 1, comprises 1st dielectric layer present in the thickness of 35nm, 2nd blocking layer in the thickness of 1nm, third functional layer in the thickness of 21nm to 24nm, fourth blocking layer in the thickness of 1nm, 5th dielectric layer present in the thickness of 38 to 43nm.
16. The coating as claimed in claim 1, comprises 1st dielectric layer present in the thickness of 37nm, 2nd blocking layer in the thickness of 1nm, third dielectric layer in the thickness of 5nm to 6nm, fourth functional layer in the thickness of 11nm, fifth blocking layer in the thickness of 17nm, 6th dielectric layer present in the thickness of 33 to 35nm.
17. The coating as claimed in claim 1, comprises 1st dielectric layer present in the thickness of 24nm, 2nd dielectric layer in the thickness of 9nm, third functional layer in the thickness of 29nm, fourth dielectric layer in the thickness of 13nm, fifth dielectric layer in the thickness of 20nm.
18. The coating as claimed in claim 1, wherein the thickness of the layers for 30% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 103nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 36nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 26nm.
19. The coating as claimed in claim 1, wherein the thickness of the layers for 55% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 39nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 25nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 41nm.
20. The coating as claimed in claim 1, wherein the thickness of the layers for 65% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 44nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 16nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 43nm;
21. The coating as claimed in claim 1, wherein the thickness of the layers for 70% transmission for a neutral shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 47nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 12nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 44nm.
22. The coating as claimed in claim 1, wherein the thickness of the layers for 30% transmission for a green shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 91nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 37nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 33nm.
23. The coating as claimed in claim 1, wherein the thickness of the layers for 45% transmission for a green shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 18nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 26nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 32nm.
24. The coating as claimed in claim 1, wherein the thickness of the layers for 55% transmission for a green shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 27nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 21nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 38nm.
25. The coating as claimed in claim 1, wherein the thickness of the layers for 30% to 45% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 25 to 94nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23 to 35nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 22 to 28nm.
26. The coating as claimed in claim 1, wherein the thickness of the layers for 55% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness of 46nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 37nm.
27. The coating as claimed in claim 1, wherein the thickness of the layers for 45% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness range of 46nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 37nm.
28. The coating as claimed in claim 1, wherein the thickness of the layers for 45% transmission for a blue shade, comprises:
a) a first dielectric layer (101) of silicon nitride present in the thickness range of 46nm;
b) first functional layer (102) comprises titanium nitride (TiN) deposited present in the thickness of 23nm;
c) a second dielectric layer (101) of silicon nitride present in the thickness of 37nm.
29. The coating as claimed in claim 1, wherein the stack comprises following layers to achieve Blue shade with transmission of 38 to 65%, reflection glass side of 7 to 20 %, reflection glass side of 3 to 15%:
a) First Dielectric layer in the thickness ranging from 54 to 60nm;
b) First Functional layer in the thickness ranging from 1 to 5 nm;
c) Second Functional layer in the thickness ranging from 4 to 35nm;
d) Second Dielectric layer in the thickness ranging from 26 to 69nm;
e) Third Functional layer 1 in the thickness ranging from 8 to 10nm;
f) Fourth Functional layer 1 in the thickness ranging from 1 to 5 nm;
g) Third Dielectric layer in the thickness ranging from 23 to 59nm.
30. A method of preparing solar control coatings for glass facades comprising:
a) depositing a dielectric layer of silicon nitride (101) over a glass substrate (100);
b) depositing a first functional layer of titanium nitride (102) on the dielectric layer of silicon nitride (101);
c) depositing a second functional layer of nickel chromium nitride (103) on the first functional layer of titanium nitride (102); and
d) depositing a second dielectric layer of silicon nitride (104) on the second functional layer of nickel chromium nitride (103)
wherein the first functional layer (102) and the second functional layer (103) are configured to achieve transmission values of solar light ranging from 10% to 70% with a neutral color spectrum and configured to maintain reflection value of solar light between 2% and 20% on the second outer surface and 5% to 30 % reflection on the first outer surface of glass substrate (100).
31. The method for enhanced solar control coatings for glass facades as claimed in claim 30, wherein layer deposition on the clear float glass substrate is performed by a physical vapor deposition (PVD) method with large area RF/DC magnetron sputtering.
32. The method for enhanced solar control coatings for glass facades as claimed in claim 30, wherein the layer deposition process is performed in a high vacuum environment with a pressure of 10 x E-6 mbar.
33. The method for enhanced solar control coatings for glass facades as claimed in claim 30, wherein while performing layer deposition process argon gas and nitrogen gas is used to create a plasma state for tuning the layer deposition process.