Indium Quantum Dots with Fluorine Surface for Toxicity Reduction
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Solution Overview
Problem
Current quantum dots, particularly those containing heavy metals like cadmium and lead, pose environmental and health risks due to their toxicity, limiting their application in optoelectronic devices despite their superior optoelectronic properties.
Innovation Solution
Development of indium-based quantum dots with a compound structure represented by In1-xMxA, where M is aluminum, gallium, or scandium, and A is nitrogen, phosphorus, arsenic, or antimony, with fluorine and oxygen bonded to the surface, enhancing light emitting properties without the use of toxic heavy metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If quantum dots containing heavy metals like cadmium and lead are used, then superior optoelectronic properties are achieved, but environmental and health risks increase due to toxicity
Solution Approach 1:
The patent changes the compositional parameters of quantum dots by replacing toxic heavy metals (Cd, Pb) with non-toxic elements (In, Ga, Al, N, P, As, Sb, Bi), while maintaining the nanocrystal structure and size range (2-50 nm) to preserve quantum confinement effects and optoelectronic properties
Solution Approach 2:
The patent creates composite quantum dot structures with core-shell configurations, where the core contains indium-based compounds (InP, InAs, InSb) and the shell contains wider bandgap materials (ZnS, CdS, ZnSe), combining the advantages of both materials to achieve high quantum yield and stability without toxic heavy metals
2Reliability
If indium-based quantum dots with fluorine and oxygen on surface are synthesized, then quantum yield and photoluminescence properties are enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates fluorine and oxygen atoms into the quantum dot surface during the synthesis process itself, rather than requiring post-synthesis treatment. The precursors are selected to provide these elements, and they are incorporated in controlled amounts (F: 10-30 at.%, O: 5-20 at.%) to achieve enhanced photoluminescence quantum yield before the quantum dots are fully formed
Solution Approach 2:
The patent optimizes specific compositional parameters including the ratio of indium to group V elements (In/A ≥ 1.2), the amount of fluorine (10-30 at.%), and oxygen (5-20 at.%) to achieve enhanced quantum yield and red-shifted photoluminescence while maintaining a relatively simple one-step synthesis process
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 indium-based quantum dots exhibit enhanced quantum yield and red-shifted photoluminescence, offering improved light emitting properties without the need for semiconductor shells, suitable for applications in solar cells, photo-detectors, and other optoelectronic devices.
Implementation Method 1
the indium-containing quantum dot may emit light having high color purity at different wavelengths
Implementation Method 2
The semiconductor nanocrystal has a very small particle size and a large surface area per unit volume, and may exhibit a quantum confinement effect
Implementation Method 3
an amount of the fluorine is greater than or equal to about 10 atomic percent (at. %) based on a total number of indium atoms included in the indium-based quantum dot, as determined by Rutherford backscattering analysis
Data Source
AI summary
An indium-containing quantum dot including a compound represented by Chemical Formula 1:In1-xMxA Chemical Formula 1wherein, in Chemical Formula 1, M is aluminum, gallium, yttrium, or scandium, A is nitrogen, phosphorous, arsenic, antimony, bismuth, or a combination thereof, and X is greater than or equal to 0 and less than 1,wherein the indium-containing quantum dot includes fluorine and oxygen to bonded to a surface of the indium-containing quantum dot,wherein an amount of the fluorine is greater than or equal to about 10 atomic percent based on a total number of indium atoms in the indium-containing quantum dot as determined by Rutherford backscattering analysis, andwherein an amount of the oxygen is about 5 atomic percent to about 50 atomic percent based on the total number of indium atoms included in the quantum dot as determined by Rutherford backscattering analysis.