Luminous Body Ligand Design for White OLED Efficiency
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Solution Overview
Problem
White OLED display devices suffer from reduced light efficiency due to absorption of white light by color filter layers, leading to inefficient emission of red, green, and blue colors in pixel regions.
Innovation Solution
A luminous body comprising a first moiety with inorganic emitting particles and a second moiety of silsesquioxanes, where one ligand is polar and the other is non-polar, is used to enhance dispersion properties and prevent fluorescent resonance energy transfer, allowing for improved light emission and efficiency in light emitting films and displays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a color filter layer is used to emit red, green, and blue colors in pixel regions, then full color display is achieved, but light efficiency is reduced due to absorption of white light
Solution Approach 1:
The invention extracts the color filtering function from a separate color filter layer and integrates it into the light emitting film itself through quantum dots. The quantum dots directly emit red, green, and blue light in their respective pixel regions without requiring a color filter layer, thereby eliminating the energy loss associated with light absorption and re-emission through filters.
Solution Approach 2:
The invention utilizes the size-dependent optical properties of quantum dots to achieve different emission colors. By controlling the size parameter of quantum dots (smaller for blue, larger for red), the system generates full-color display directly from the light emitting material, bypassing the need for color filter layers and improving overall light efficiency.
2Loss of energy
If quantum dots are used to improve light efficiency, then fluorescence resonance energy transfer occurs between particles, reducing emission efficiency
Solution Approach 1:
The invention applies different surface treatments to quantum dots based on their local environment and emission wavelength. Quantum dots emitting different colors receive tailored surface modifications with appropriate ligands and shell structures, optimizing each particle's resistance to fluorescence resonance energy transfer according to its specific optical properties and position in the device.
Solution Approach 2:
The invention creates composite quantum dot structures with multiple components including core quantum dots, shell layers, and surface ligands. These composite structures are designed to prevent fluorescence resonance energy transfer while maintaining high emission efficiency, with each component serving a specific function in eliminating energy loss between particles.
3Reliability
If quantum dots with improved emission efficiency are used, then dispersion in solvents and matrix resins deteriorates, affecting device fabrication
Solution Approach 1:
The invention modifies the surface chemistry parameters of quantum dots by introducing amine-functionalized oligosilsesquioxane ligands. This surface modification changes the polarity and steric properties of quantum dot surfaces, enabling them to disperse uniformly in both polar and non-polar solvents while maintaining their high emission efficiency and preventing aggregation.
Solution Approach 2:
The invention employs composite ligand structures combining organic amine groups with inorganic silsesquioxane frameworks. This hybrid composite material provides both the emission efficiency of quantum dots and the dispersion capabilities of amphiphilic molecules, allowing quantum dots to be compatible with various solvent systems used in device fabrication.
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 luminous body achieves enhanced dispersion in various solvents and matrix resins, preventing energy transfer between particles and improving quantum efficiency and emission properties, thereby increasing light efficiency in OLED displays.
Implementation Method 1
preventing fluorescent resonance energy transfer between particles and improving quantum efficiency and emission properties
Data Source
AI summary
A luminous body includes a first moiety including a plurality of first ligands combined to a surface of an inorganic emitting particle; and a second moiety including silsesquioxanes connected to a second ligand connected to one of the first ligands, wherein one of the first and second ligands is a polar ligand, and the other one of the first and second ligands is a non-polar ligand.