Yttrium-Inclusive Nitrided Dielectric Layer for Low-E Coating Thermal Stability
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Solution Overview
Problem
Conventional low-E coatings using titanium oxide dielectric layers are not thermally stable after heat treatment, leading to thermal stress and deteriorated performance, and have low deposition rates, resulting in high production costs.
Innovation Solution
The use of yttrium inclusive high index nitrided dielectric layers such as YZrSiAlN, YZrSiN, and YSiN, which are heat treatable and can be deposited at higher rates, providing high refractive index and low absorption, thus replacing TiO2 layers in low-E coatings for improved thermal stability and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If titanium oxide dielectric layers are used in low-E coatings, then high refractive index is achieved for antireflection purposes, but thermal stability deteriorates after heat treatment due to film crystallization
Solution Approach 1:
The patent changes the material composition parameters by replacing TiO2 with nitrided dielectric layers containing Y, Zr, Si, and Al. This compositional parameter change maintains high refractive index while achieving thermal stability through the formation of crystalline phases like Y3Nb5O14 and ZrSiO4 that resist detrimental crystallization during heat treatment.
Solution Approach 2:
The patent employs composite dielectric layers combining multiple elements (Y, Zr, Si, Al, N, O) to create a material system that integrates both high refractive index properties and thermal stability. The composite nature allows synergistic effects where different elements contribute to optical properties while forming stable crystalline structures for thermal resistance.
2Illumination intensity
If titanium oxide dielectric layers are used in low-E coatings, then high refractive index is achieved, but deposition rate decreases leading to high production costs
Solution Approach 1:
The patent modifies the deposition process parameters and material composition to achieve higher deposition rates. The nitrided dielectric layer formulation with Y, Zr, Si, and Al enables faster sputter deposition while maintaining the required high refractive index, directly improving production efficiency and reducing costs.
3Illumination intensity
If titanium oxide dielectric layers are used in low-E coatings, then antireflection is achieved, but thermal stress increases causing deterioration of low E stack performance
Solution Approach 1:
The patent changes the material composition to nitrided dielectric layers with specific elemental ratios (Y, Zr, Si, Al, N, O) that maintain antireflection performance through high refractive index while simultaneously reducing thermal stress. The resulting crystalline phases have lower thermal stress and better adhesion to adjacent layers, preserving low E stack performance after heat treatment.
4Illumination intensity
If conventional TiO2 dielectric layers are used, then high refractive index is achieved, but adhesion to adjacent layers deteriorates after heat treatment
Solution Approach 1:
The patent modifies the dielectric layer composition to include Y, Zr, Si, and Al in specific ratios, creating a material that maintains high refractive index while developing superior adhesion properties. The nitrided structure and resulting crystalline phases (Y3Nb5O14, ZrSiO4) provide enhanced bonding to adjacent low E layers, preventing delamination after heat treatment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The yttrium inclusive nitrided dielectric layers maintain refractive index stability during heat treatment and offer higher deposition rates, enhancing the thermal stability and performance of low-E coatings in window applications while reducing production costs.
Implementation Method 1
these materials can be sputter-deposited at much higher sputter-deposition rates than can TiO2
Implementation Method 2
a transparent dielectric high index layer, with a high refractive index (n) and low k value
Implementation Method 3
low absorption (low k value, measured at 400 nm)
Implementation Method 4
heat treatment (HT), and can be sputter-deposited at much higher sputter-deposition rates than can TiO2. These materials have also been found to be heat stable (e.g., the variation of refractive index n may be no greater than 0.1 due to HT such as thermal tempering at about 650° C.)
Data Source
AI summary
A coated article includes a low emissivity (low-E) coating having at least one infrared (IR) reflecting layer of a material such as silver, gold, or the like, and at least one yttrium (Y) inclusive high index nitrided dielectric layer. In certain example embodiments, the yttrium inclusive high index nitrided dielectric layer(s) may be of or include one or more of YZrSiAlN, YZrSiN, YSiN, and/or YSiAlN. The high index layer may be a transparent dielectric high index layer, with a high refractive index (n) and low k value, in preferred embodiments and may be provided for antireflection purposes and/or visible transmission purposes, and/or for improving thermal stability. In certain example embodiments, the low-E coating may be used in applications such as monolithic or insulating glass (IG) window units, vehicle windows, or the like.