Nanostructured TCO Electrochromic Device Plasmon Resonance
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Solution Overview
Problem
Existing electrochromic technologies face challenges in stability under repeated cycling, limiting their application in smart window coatings, particularly due to the inability to dynamically modify the plasmon resonance frequencies of semiconductor nanocrystals and the formation of insulating barriers between nanostructures.
Innovation Solution
The development of an electrochromic device using nanostructured transparent conducting oxide (TCO) films, where the surface plasmon resonance is dynamically modulated through electrochemical doping, allowing for reversible changes in the free carrier concentration and dielectric environment, thereby enhancing the stability and optical properties of the films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If semiconductor nanocrystals are used for electrochromic devices, then plasmon resonance frequency modulation is achieved, but stability under repeated cycling deteriorates due to insulating barrier formation
Solution Approach 1:
The patent changes the material parameter from semiconductor nanocrystals to transparent conducting oxide nanocrystals, which maintain high electrical conductivity after electrochemical doping. This parameter change eliminates the formation of insulating barriers while preserving the ability to modulate plasmon resonance frequency through electrochemical doping, thus resolving the contradiction between adaptability and reliability.
2Stability of the object's composition
If hydrocarbon ligands are used to cap nanocrystal surfaces, then nanocrystal stability is improved, but electrical conductivity deteriorates due to insulating barriers between nanocrystals
Solution Approach 1:
The patent changes the ligand parameter from hydrocarbon ligands to short-chain carboxylic acid ligands. This parameter change reduces the insulating barrier thickness between nanocrystals, allowing electrical conductivity to be maintained or enhanced while preserving nanocrystal surface stability. The shorter ligand chain length enables better electrical coupling between adjacent nanocrystals.
Solution Approach 2:
The patent uses short-chain carboxylic acid ligands that can be easily exchanged or removed during processing. These short-living ligands serve their purpose of stabilizing nanocrystals during synthesis but are subsequently replaced or eliminated to achieve high conductivity in the final device, sacrificing the ligand's long-term stability function for the benefit of electrical conductivity.
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 solution achieves significant modulation of the plasmon resonance frequency, resulting in a high contrast ratio for near-infrared transmittance and improved durability, with minimal impact on visible light transmission, enabling robust and dynamic smart window performance.
Implementation Method 1
Localized surface plasmon absorption features arise at high doping levels in semiconductor nanocrystals, appearing in the near infrared range
Implementation Method 2
the surface plasmon resonance is dynamically modulated through electrochemical doping, allowing for reversible changes in the free carrier concentration and dielectric environment
Implementation Method 3
an electrochromic device using nanostructured transparent conducting oxide (TCO) films, where the surface plasmon resonance is dynamically modulated through electrochemical doping
Data Source
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AI summary
The embodiments described herein provide an electrochromic device. In an exemplary embodiment, the electrochromic device includes (1) a substrate and (2) a film supported by the substrate, where the film includes transparent conducting oxide (TCO) nanostructures. In a further embodiment, the electrochromic device further includes (a) an electrolyte, where the nanostructures are embedded in the electrolyte, resulting in an electrolyte, nanostructure mixture positioned above the substrate and (b) a counter electrode positioned above the mixture. In a further embodiment, the electrochromic device further includes a conductive coating deposited on the substrate between the substrate and the mixture. In a further embodiment, the electrochromic device further includes a second substrate positioned above the mixture.