Quantum Dot Surface Coordination for Higher Light-Emitting EQE
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Solution Overview
Problem
Existing techniques fail to significantly improve the quantum yield of quantum dot solutions, leading to low external quantum efficiency (EQE) in light-emitting elements.
Innovation Solution
A quantum-dot-containing composition is developed, featuring quantum dots with surfaces provided with either one equivalent crystal plane or two or more different equivalent crystal planes, in conjunction with specific compounds or halogen/chalcogen atoms that tightly coordinate to defects and bond to multiple crystal plane orientations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If halogen atoms are coordinated to quantum dot surfaces to improve quantum yield, then the binding strength increases due to strong electronegativity, but the quantum yield improvement is insufficient
Solution Approach 1:
The patent changes the chemical parameters by introducing chalcogen atoms (S, Se, Te) with different electronegativities and bonding characteristics compared to halogen atoms. This parameter change allows for optimized coordination strength and improved quantum yield that cannot be achieved with halogens alone.
Solution Approach 2:
The patent creates a composite coordination environment on the quantum dot surface by combining multiple types of ligands including halogen-containing compounds, chalcogen-containing compounds, and their mixtures. This composite approach leverages the complementary strengths of different atom types to achieve superior quantum yield and light-emitting efficiency.
2Reliability
If quantum dots with specific crystal planes are used to improve ligand coordination, then the surface defect management improves, but the manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by targeting specific crystal planes ((001), (011), (111)) with appropriate ligand types. Different crystal planes have different atomic arrangements and defect characteristics, and the patent optimizes ligand coordination for each plane type to maximize quantum yield while managing manufacturing through systematic ligand selection.
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 enhances the quantum yield of quantum dot solutions and increases the EQE of light-emitting elements by effectively managing surface defects and improving ligand coordination.
Implementation Method 1
The effect of improving the quantum yield of the quantum dots is caused perhaps because strong electronegativity allows the halogen to tightly coordinate to the surface of the quantum dots.
Implementation Method 2
a haloid salt is bonded to at least a portion of a surface of quantum dots
Data Source
AI summary
A quantum-dot-containing composition contains: either quantum dots each having a surface provided with only one equivalent crystal plane, or quantum dots each having a surface provided with two or more different equivalent crystal planes; and one selected from (A), (B), and (C) below: (A) two or more compounds; (B) one or more compounds, and single atoms formed of one or more halogens or chalcogens; and (C) single atoms formed of two or more halogens or chalcogens.