Surface-Modified Quantum Dots for Ink-Jet Printable Curable Compositions
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Solution Overview
Problem
Current quantum dot compositions face challenges in achieving high light efficiency and processability due to hydrophobic surface characteristics, limited solvent compatibility, and viscosity issues, which restrict their application in polar systems and ink-jet printing processes.
Innovation Solution
Surface-modified quantum dots with specific ligands, such as those represented by Chemical Formula 1, are used in non-solvent and solvent-based curable compositions, including polymerizable monomers and light diffusing agents, to enhance dispersibility and optical characteristics, allowing for higher concentrations and improved viscosity for ink-jet printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If quantum dots are added to increase light efficiency, then light efficiency is improved, but viscosity exceeds the range capable of ink-jetting
Solution Approach 1:
A surface-modifying ligand acts as an intermediary between the quantum dot core and the polar solvent system. The ligand contains both hydrophobic groups (for interaction with the quantum dot core) and hydrophilic groups (for compatibility with polar solvents and binders), enabling high-concentration quantum dot dispersions without excessive viscosity increase
Solution Approach 2:
The patent changes the chemical parameters of the quantum dot surface by introducing specific ligands with controlled hydrophilic-hydrophobic balance. This modification allows the quantum dots to maintain colloidal stability in polar systems at high concentrations while keeping the overall composition viscosity within ink-jet printable ranges (below 12 cPs)
2Ease of manufacture
If quantum dots are dispersed in solvent based composition, then processability is improved, but nozzle drying and nozzle clogging worsen
Solution Approach 1:
The patent shifts the solvent system from high-volatility organic solvents to low-volatility polar solvents or non-solvent systems. This parameter change reduces solvent evaporation rate, preventing nozzle drying and clogging during ink-jet printing, while maintaining adequate processability through optimized composition formulation
Solution Approach 2:
The patent eliminates the need for volatile solvents that require frequent nozzle maintenance. By using non-volatile or low-volatility carriers, the system reduces operational interruptions for nozzle cleaning and drying, improving continuous manufacturing capability
3Adaptability or versatility
If quantum dots are surface-modified with ligands, then dispersibility in polar systems is improved, but complexity of composition increases
Solution Approach 1:
The patent creates a composite ligand structure combining hydrophobic and hydrophilic moieties into a single molecule. This composite approach enables dual functionality (quantum dot binding and solvent compatibility) without requiring multiple separate components, thus improving dispersibility while minimizing composition complexity
Solution Approach 2:
The surface-modifying ligand performs multiple functions simultaneously: it anchors to the quantum dot core, provides steric stabilization, enables polar solvent compatibility, and controls viscosity. This multi-functionality reduces the need for additional separate additives, simplifying the overall composition
4Object-generated harmful factors
If non-solvent based quantum dot ink is used, then nozzle clogging is reduced, but light efficiency and absorption rate decrease
Solution Approach 1:
The patent optimizes the concentration parameter of quantum dots in non-solvent systems by introducing surface-modifying ligands. This allows achieving higher quantum dot concentrations (above 20 wt%) in non-solvent-based compositions, thereby increasing light efficiency and absorption rate while maintaining the nozzle-clogging-free advantage of non-solvent systems
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 surface-modified quantum dots exhibit improved optical characteristics, increased light efficiency, and enhanced processability, enabling their use in high-concentration dispersions within non-solvent and solvent-based curable compositions for applications like color filters and display devices.
Implementation Method 1
a quantum dot... having a maximum fluorescence emission wavelength at about 500 nm to about 680 nm
Implementation Method 2
a quantum dot is surface-modified with a compound represented by Chemical Formula 1
Implementation Method 3
a non-solvent curable composition includes... a polymerizable monomer having a carbon-carbon double bond at a terminal end
Data Source
AI summary
A quantum dot surface-modified with a specific compound, a non-solvent curable composition including the quantum dot, a solvent based curable composition including the quantum dot, a cured layer manufactured utilizing the curable composition, a color filter including the cured layer, and a display device including the cured layer are disclosed.