Indium Aluminum Quantum Dot Core-Shell Structure for Non-Cadmium Emission
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Solution Overview
Problem
Current quantum dots used in optical members and electronic apparatuses face challenges in achieving high photoluminescence quantum yield without using cadmium, a toxic element, while maintaining stability and luminescence efficiency.
Innovation Solution
A quantum dot composition including a core of indium (In) and aluminum (Al) with a Group I element shell, where the atomic ratio of Al to In is between 0.9 and 2.4, emitting visible light other than blue light, and optionally including additional elements to form Group I-III-VI semiconductor compounds, is developed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If cadmium is used in quantum dots to achieve high photoluminescence quantum yield, then luminescence efficiency is improved, but toxicity increases
Solution Approach 1:
The patent removes cadmium from the quantum dot composition entirely, extracting the harmful element while maintaining the desired optical properties through alternative material combinations (indium-based cores with aluminum shell structures).
Solution Approach 2:
The patent changes the compositional parameters by using indium aluminum oxide core-shell structures with specific atomic ratios (Al/In ratio between 0.9 and 2.4), achieving high photoluminescence quantum yield without cadmium through controlled material composition changes.
2Object-affected harmful factors
If quantum dot composition is simplified to avoid cadmium, then toxicity is reduced, but maintaining high photoluminescence quantum yield becomes difficult
Solution Approach 1:
The patent employs composite material structures combining indium oxide core with aluminum oxide shell, creating a composite quantum dot system that achieves both non-toxicity and high photoluminescence quantum yield through synergistic material combination.
Solution Approach 2:
The patent optimizes compositional parameters including the Al/In atomic ratio (0.9 to 2.4), core shell thickness ratios, and stoichiometry to maintain high photoluminescence quantum yield while eliminating cadmium from the composition.
3Loss of energy
If quantum dots are designed for high luminescence efficiency, then photoluminescence quantum yield is improved, but achieving stability becomes more difficult
Solution Approach 1:
The patent uses composite indium aluminum oxide structures where the aluminum oxide shell provides protective stabilization while the indium oxide core maintains high luminescence efficiency, achieving both performance and stability simultaneously.
Solution Approach 2:
The patent applies different material properties to different regions: the indium oxide core provides high photoluminescence quantum yield while the aluminum oxide shell provides chemical stability and protection, with each region optimized for its specific function.
4Adaptability or versatility
If quantum dots emit blue light, then the emission spectrum is complete, but color purity and reproducibility are reduced
Solution Approach 1:
The patent controls the quantum dot size and compositional parameters (Al/In ratio, core shell thickness) to shift the emission wavelength away from blue light (450-495nm) toward green-cyan regions (500-520nm), achieving improved color purity while maintaining spectral utility.
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 quantum dots with high luminescence efficiency, stability, and the ability to emit visible light within a specific range, improving color purity and reproducibility while avoiding the use of cadmium.
Implementation Method 1
the quantum dot may emit visible light other than blue light... a photoluminescence quantum yield (PLQY) of the quantum dot may be in a range of about 50% to about 98%
Data Source
AI summary
Embodiments provide a quantum dot, an optical member including the quantum dot, an electronic apparatus including the quantum dot, and a method of preparing the quantum dot. The quantum dot includes a core including indium (In) and A1, and a first shell covering the core, not including In, and including A1. A1 is a Group I element, an atomic ratio of A1 to In in the quantum dot is in a range of about 0.9 to about 2.4, and the quantum dot emits visible light other than blue light.