Non-Toxic Quantum Dot Ligand Design for Solubility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing quantum dots containing mercury (Hg) and cadmium (Cd) pose environmental pollution and health risks, and they have limited solubility in hydrophilic solvents, affecting the efficiency and compatibility of light-emitting devices and optical members.
Innovation Solution
Development of quantum dots without mercury and cadmium, featuring a nanoparticle with a core-shell structure and ligands containing thiol and hydrophilic groups, which enhance solubility and charge injection efficiency, allowing for improved luminescence and reduced environmental impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If quantum dots containing mercury and cadmium are used, then luminescence efficiency is improved, but environmental pollution and health risks increase
Solution Approach 1:
The patent changes the chemical composition parameters of quantum dots by replacing toxic mercury and cadmium with non-toxic materials such as carbon, silicon, or their compounds. This parameter change maintains luminescence efficiency while eliminating harmful environmental and health effects, directly resolving the technical contradiction between performance and safety.
2Use of energy by moving object
If quantum dots are designed for high luminescence efficiency, then solubility in hydrophilic solvents is limited, but device compatibility and processing efficiency improve
Solution Approach 1:
The patent creates composite quantum dot structures by combining non-toxic core materials (carbon, silicon) with hydrophilic shell materials or surface functional groups. This composite approach enables simultaneous achievement of high luminescence efficiency from the core and improved solubility in hydrophilic solvents through the shell, resolving the contradiction between performance and processability.
Solution Approach 2:
The patent applies different properties to different parts of the quantum dot structure: the core maintains high luminescence efficiency with non-toxic materials, while the surface or shell is modified with hydrophilic groups to enhance solubility. This local differentiation of properties allows the quantum dot to simultaneously satisfy both requirements.
3Manufacturing precision
If quantum dot size is reduced to achieve narrow emission bandwidth, then charge injection ability deteriorates, but color purity improves
Solution Approach 1:
The patent uses composite structures where a small-sized core provides narrow emission bandwidth and high color purity, while a surrounding shell or surface modification layer facilitates charge injection. This composite design allows the small core to maintain its optical advantages while the shell compensates for the charge injection limitations of reduced size.
Solution Approach 2:
The patent introduces an intermediary shell or surface layer between the small quantum dot core and the surrounding environment. This intermediary structure mediates the charge injection process, enabling efficient charge transfer despite the small core size, while the core itself maintains its narrow emission bandwidth and high color purity.
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 provides enhanced luminescence efficiency, improved solubility in hydrophilic solvents, and reduced environmental and health risks, while maintaining excellent bandgap characteristics, thus improving the performance and sustainability of light-emitting devices and optical members.
Implementation Method 1
Quantum dots are semiconductor nanocrystals that exhibit a quantum confinement effect. When quantum dots receive light from an excitation source and reach an excited energy state, they emit energy autonomously according to a corresponding energy band gap.
Implementation Method 2
the at least one ligand includes at least two thiol groups and at least one hydrophilic group
Data Source
AI summary
A quantum dot, and an ink composition, a light-emitting device, an optical member, and an apparatus, each including the quantum dot. The quantum dot includes: a nanoparticle; and at least one ligand on a surface of the nanoparticle, wherein the nanoparticle does not include mercury and cadmium, and the at least one ligand includes at least two thiol groups and at least one hydrophilic group.