Quantum Dot-Polymer Composite for High Luminous Efficiency
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Solution Overview
Problem
Conventional quantum dot-polymer composite patterns face challenges in achieving high luminous efficiency and color reproducibility due to defects formed during the heat-treatment process, which reduce the quantum dot's light emission efficiency and increase deep trap emission.
Innovation Solution
A quantum dot-polymer composite pattern is developed with a polymer matrix containing cadmium-free quantum dots and a linear polymer with a carboxylic acid group, where the pattern is treated under controlled humidity and temperature conditions after post-baking to minimize surface defects and enhance light absorption and emission properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If heat-treatment process is applied to quantum dot-polymer composite pattern, then manufacturing completeness is improved, but surface defects are generated and quantum dot light emission efficiency deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer matrix by incorporating carboxylic acid group-containing repeating units with specific acid values (50-250 mg KOH/g). This chemical parameter change enables the polymer to chemically interact with quantum dot surfaces, passivating defects without requiring aggressive heat-treatment that would damage the quantum dots.
Solution Approach 2:
The carboxylic acid groups in the polymer matrix act as intermediary substances that mediate between the quantum dot surfaces and the polymer matrix. These functional groups chemically bind to the quantum dot surfaces, serving as a protective intermediary layer that prevents defect formation while allowing the composite to be manufactured through standard heat-treatment processes.
2Device complexity
If conventional polymer matrix is used in quantum dot-polymer composite, then manufacturing simplicity is maintained, but luminous efficiency and color reproducibility deteriorate
Solution Approach 1:
The patent creates a composite material system where cadmium-free quantum dots are dispersed in a specially designed polymer matrix containing carboxylic acid group-containing repeating units. This composite structure combines the optical properties of quantum dots with the chemical functionality of the polymer, achieving both high luminous efficiency and color reproducibility while maintaining manufacturing simplicity through a single composite material formulation.
Solution Approach 2:
The patent modifies the polymer matrix parameters by specifying carboxylic acid group content (acid value of 50-250 mg KOH/g) and molecular weight ranges. These parameter changes enable the polymer to provide optimal chemical environment for quantum dot dispersion and stabilization, significantly improving luminous efficiency and color reproducibility compared to conventional polymers without requiring complex manufacturing processes.
3Quantity of substance
If quantum dot concentration is increased to improve light absorption, then light absorption rate is improved, but deep trap emission increases
Solution Approach 1:
The patent changes the chemical environment parameters within the polymer matrix by incorporating carboxylic acid groups at controlled concentrations. This creates a chemical parameter gradient that allows high quantum dot concentration for optimal light absorption while the carboxylic acid groups passivate surface states that would otherwise create deep trap emission, enabling simultaneous optimization of both light absorption and emission quality.
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 approach results in improved luminous efficiency and reduced deep trap emission, achieving a quantum dot-polymer composite with enhanced light absorption and emission characteristics, exceeding 33% luminous efficiency and minimizing deep trap contribution to quantum yield.
Implementation Method 1
at least one repeating section configured to emit light of a predetermined wavelength, wherein the quantum dot-polymer composite has a light absorption rate of greater than or equal to about 85% at wavelength of about 450 nanometers (nm)
Implementation Method 2
a polymer matrix including a linear polymer including a carboxylic acid group-containing repeating unit and a plurality of cadmium-free quantum dots dispersed in the polymer matrix
Data Source
AI summary
A quantum dot-polymer composite pattern including at least one repeating section configured to emit light of a predetermined wavelength, and a production method and a display device including the quantum dot-polymer composite are disclosed. The quantum dot-polymer composite includes a polymer matrix including linear polymer including a carboxylic acid group-containing repeating unit and a plurality of cadmium-free quantum dots dispersed in the polymer matrix, has an absorption rate of greater than or equal to about 85% for light at wavelength of about 450 nm, and has an area ratio of a hydroxy group peak relative to an acrylate peak of greater than or equal to about 2.6 in Fourier transform infrared spectroscopy.