InP Core-Shell Nanoparticle Aggregates for Narrow Emission
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Solution Overview
Problem
Conventional InP-based semiconductor nanoparticles face challenges in achieving both high quantum yield and narrow full width at half maximum, as improving one property often compromises the other.
Innovation Solution
A semiconductor nanoparticle aggregate with a core/shell type structure, where the core includes In and P, and the shell has one or more layers, is developed. Specific parameters such as the average full width at half maximum, standard deviation of peak wavelength, and standard deviation of full width at half maximum are optimized to achieve high quantum yield and narrow emission spectra.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If InP-based semiconductor nanoparticles are used to replace Cd-based nanoparticles, then environmental safety is improved, but quantum yield decreases and emission wavelength control becomes difficult
Solution Approach 1:
The patent employs a core-shell composite structure where InP-based semiconductor nanoparticles form the core and are coated with a shell layer. This composite structure allows the core to provide high quantum yield and the shell to control emission wavelength, thereby achieving both environmental safety and high performance simultaneously.
2Manufacturing precision
If the particle diameter of semiconductor nanoparticles is reduced to achieve narrow emission spectrum, then full width at half maximum is reduced, but quantum yield decreases due to increased surface effects
Solution Approach 1:
The patent uses a thin shell layer surrounding the nanoparticle core. The shell is thin enough to maintain the quantum confinement effect and narrow emission spectrum of small particles, yet sufficient to passivate surface defects that would otherwise reduce quantum yield. This resolves the contradiction between narrow emission width and high quantum yield.
3Reliability
If shell thickness is increased to improve quantum yield, then quantum yield increases, but emission spectrum width increases
Solution Approach 1:
The patent optimizes the shell thickness to a specific range that balances quantum yield enhancement with emission spectrum narrowing. By precisely controlling the shell thickness parameter, the invention achieves maximum quantum yield while maintaining narrow full width at half maximum, resolving the trade-off between these two parameters.
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 semiconductor nanoparticle aggregate achieves a high quantum yield of 80% or more and a narrow full width at half maximum, effectively addressing the market requirements and improving the performance of quantum dot devices.
Implementation Method 1
Excitons formed in the semiconductor particles by means such as photoexcitation and charge injection emit photons having energy depending on the band gap by recombination. Therefore, the emission wavelength can be controlled by adjusting the crystal size of the semiconductor nanoparticles
Implementation Method 2
Such semiconductor nanoparticles are microscopic particles that may exhibit a quantum confinement effect and the width of the band gap varies depending on the size of the nanoparticles
Data Source
AI summary
A semiconductor nanoparticle aggregate that is an aggregate of core/shell type semiconductor nanoparticles including a core including In and P and a shell having one or more layers, in which a peak wavelength of an emission spectrum of the semiconductor nanoparticle aggregate is from 515 nm to 535 nm and a full width at half maximum of the emission spectrum is 43 nm or less. For each semiconductor nanoparticle, (1) an average value of a full width at half maximum of an emission spectrum is 15 nm or more, (2) a standard deviation of a peak wavelength of the emission spectrum is 12 nm or less, and (3) a standard deviation of the full width at half maximum of the emission spectrum is 2 nm or more.