Photo-Reactive QD Composition Without TiO2 for Stable Inkjet Printing
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Solution Overview
Problem
Existing quantum dot (QD) inks face issues with sedimentation due to high density and large particle size of TiO2 scattering particles, leading to viscosity increase and ink-jet printing problems, and require improved optical properties and compatibility with bank structures.
Innovation Solution
A photo-reactive composition with reduced or no scattering particles, achieving high External Quantum Efficiency (EQE) and haze values, improved compatibility with bank structures, and lower viscosity, suitable for inkjet printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If TiO2 particles are added to QD ink for light scattering, then haze value is improved, but viscosity increases significantly and sedimentation occurs
Solution Approach 1:
The patent removes TiO2 scattering particles from the QD ink formulation entirely, extracting the harmful element that causes viscosity increase and sedimentation. The invention achieves this by using a bank structure with specific refractive index properties to provide the necessary light scattering function without requiring particulate additives in the ink.
Solution Approach 2:
The patent introduces a bank structure as an intermediary element that performs the light scattering function. The bank, with its specific refractive index (1.4-1.6) and structural properties, acts as a mediator between the QD ink and the desired optical output, providing haze enhancement without the ink itself containing scattering particles.
2Loss of energy
If TiO2 particles are used for light scattering, then haze value increases, but ink-jet printing becomes difficult due to sedimentation
Solution Approach 1:
The patent extracts TiO2 particles from the ink formulation, eliminating the sedimentation problem that prevents reliable ink-jet printing. The scattering function is transferred to the bank structure, allowing the ink to remain particle-free and printably stable.
Solution Approach 2:
Instead of adding scattering particles to the ink to achieve haze, the patent inverts the approach by creating a bank structure with optical properties that provide haze enhancement. The scattering function is moved from the ink phase to the bank structure, enabling printability while maintaining optical performance.
3Loss of energy
If TiO2 particles are added to achieve high haze, then EQE improves, but blue leakage increases
Solution Approach 1:
The patent removes TiO2 particles from the system, eliminating the source of blue leakage associated with these scattering particles. The EQE enhancement is maintained through the bank structure's optical design rather than through particulate scattering in the ink.
Solution Approach 2:
The patent changes the optical parameters of the bank structure, specifically its refractive index (1.4-1.6) and physical dimensions, to optimize light scattering and absorption properties. This parametric optimization enables high EQE while suppressing blue leakage without requiring TiO2 particles.
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 composition achieves higher EQE and haze values, improved compatibility, and reduced viscosity, enabling efficient inkjet printing with enhanced optical properties and chemical stability.
Implementation Method 1
TiO2 particles that are typically used as scattering particles in QD inks
Implementation Method 2
at least one light emitting moiety
Data Source
AI summary
The present invention relates to a composition comprising at least one light emitting moiety.