Electrochromic Films via Low-Temperature Polyoxometalate Condensation
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Solution Overview
Problem
Current electrochromic technologies for smart windows are hindered by high costs and limited performance due to challenging film processing methods, particularly vacuum-operated sputtering techniques.
Innovation Solution
A low-temperature chemical condensation process for producing networked metal oxide films using polyoxometalates (POMs) on transparent substrates, which involves forming a POM film, curing it in an acidic environment, and optionally incorporating near-infrared plasmonic nanocrystals to enhance electrochromic properties, allowing for cost-effective and efficient solution-based manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum-operated sputtering chambers are used to deposit electrochromic films, then film quality and performance are improved, but manufacturing cost and device complexity increase significantly
Solution Approach 1:
The patent replaces the mechanical vacuum sputtering system with a chemical solution-based deposition process. Instead of using vacuum chambers and sputtering guns, the invention uses liquid precursors that are deposited via spin-coating or dip-coating methods, followed by thermal annealing to form the electrochromic film. This substitution of mechanical vacuum processes with chemical solution processes dramatically simplifies the manufacturing equipment and reduces costs while maintaining film quality.
Solution Approach 2:
The invention changes the deposition parameters from vacuum-based physical sputtering to solution-based chemical deposition. By using liquid precursors containing metal salts and organic ligands, the process operates at atmospheric pressure and moderate temperatures, eliminating the need for expensive vacuum equipment while achieving comparable or superior film properties through controlled chemical reactions and thermal processing.
2Duration of action of stationary object
If conventional high-temperature processing methods are used to create electrochromic films, then film durability is improved, but energy consumption and processing complexity increase
Solution Approach 1:
The patent modifies the processing temperature parameters by using solution-based precursors that decompose and form films at lower temperatures (typically 300-500°C) compared to conventional sputtering methods that require higher temperatures. The chemical composition of the precursor solutions is designed to facilitate low-temperature film formation, reducing energy consumption while achieving durable films through controlled thermal decomposition and crystallization processes.
3Manufacturing precision
If complex vacuum sputtering processes are used, then film precision and uniformity are improved, but manufacturing time and process complexity increase
Solution Approach 1:
The patent replaces complex mechanical vacuum sputtering systems with simple solution deposition techniques. The uniformity of the film is achieved through controlled solution application methods (spin-coating, dip-coating) and uniform thermal annealing, eliminating the need for complex vacuum chamber mechanics, sputtering gun positioning systems, and magnetic field control, thereby simplifying the overall process while maintaining film uniformity.
Solution Approach 2:
The invention incorporates preliminary actions by pre-formulating the electrochromic film material as a liquid precursor solution containing all necessary components (metal salts, organic ligands, solvents) in optimal proportions. This preliminary preparation allows the film to be deposited in a single step followed by simple thermal treatment, eliminating the need for multiple sputtering steps, in-situ heating, and complex process sequencing required by conventional methods.
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 results in electrochromic films with higher coloration efficiency, faster optical switching, and improved durability, enabling energy-saving performance while reducing manufacturing costs and environmental impact.
Implementation Method 1
a) depositing a polyoxometalate (POM) solution onto a substrate to form a film
Implementation Method 2
curing the POM film in an acidic environment to condense the POM film
Implementation Method 3
Electrochromic materials have been suggested for use with energy efficient windows, as these coatings are able to reversibly change their solar transmittance under the application of a small electrical potential
Data Source
AI summary
Described are electrochromic films produced by low temperature condensation of polyoxometalates and applications thereof. A method of producing an electrochromic film includes depositing a polyoxometalate (POM) solution on a substrate to form a POM film. The POM solution includes anionic POM clusters and counter ions, and may be doped with near-infrared plasmonic nanocrystals. The film is chemically cured using an acid to condense the POM clusters within the POM film. Another method of producing an electrochromic film includes electrochemical deposition and condensation of POM clusters.