Transparent Conductive Coatings With High NIR Transmission and Low Resistivity
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Solution Overview
Problem
Current transparent conductive materials, such as indium tin oxide (ITO), exhibit poor transmission performance in the near infrared (NIR) wavelength range while maintaining high electrical conductivity, which is a challenge for applications like high-efficiency solar cells and IR photodetectors.
Innovation Solution
A method involving the deposition of a transparent conductive material layer, typically indium tin oxide, on a substrate followed by high-temperature annealing at least 450°C for 2 minutes, achieving a transmission of at least 70% at 1550 nm and a Haacke figure of merit of at least 40×10−4Ω−1, while maintaining low resistivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high transmission in the near infrared range is achieved, then near infrared transmission is improved, but electrical conductivity deteriorates
Solution Approach 1:
The patent resolves this contradiction through parameter changes in the annealing process (temperature ≥450°C, time ≥2 minutes). This thermal parameter transformation simultaneously optimizes both optical transmission in the near infrared range and electrical conductivity, achieving a Haacke figure of merit of at least 40×10⁻⁴Ω⁻¹ by coordinating improvements in both properties rather than trading one for the other
2Illumination intensity
If the thickness of the transparent conductive material layer is reduced to improve transmission, then optical transmission is improved, but electrical conductivity deteriorates
Solution Approach 1:
The patent applies parameter changes through high-temperature annealing (≥450°C for ≥2 minutes) that transforms the electrical properties of the thin film. This thermal treatment enables thin layers to maintain low resistivity while achieving high optical transmission, effectively decoupling the thickness-dependent trade-off between optical and electrical performance
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
This approach enhances both the NIR transmission and electrical conductivity of the transparent conductive materials, achieving a balance between sheet resistance and optical transmission, thereby improving their performance in optoelectronic devices.
Implementation Method 1
annealing the transparent conductive material at a temperature of at least about 450° C. for at least about 2 min
Implementation Method 2
the depositing comprises physical vapor deposition
Implementation Method 3
the depositing comprises magnetron sputtering
Data Source
AI summary
A method is provided for manufacturing an article comprising a transparent conductive material, wherein a transparent conductive material (e.g., indium tin oxide) is deposited onto a substrate (e.g., fused silica) by physical vapor deposition, then annealed at high temperature (i.e., at least 450° C.) in a nitrogen atmosphere. The resulting article comprises a transparent conductive material that reduces the trade-off between low resistivity (or sheet resistance) and high near infrared transmission. For example, the transparent conductive material thus obtained may possess a transmission of at least 80% at 1550 nm while having a resistivity of less than or equal to about 5×10−4 Ohm-cm and a Haacke figure of merit of at least about 40×10−4Ω−1. Also provided is a method for modulating the resistivity and/or the near infrared transmission of a transparent conductive material by annealing the transparent conductive material at a high temperature under nitrogen atmosphere.