Core Shell Particle Silicon Ratio Control

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Solution Overview

Problem

The synthesis of core shell particles with high luminous efficacy and narrow emission half-width is challenging due to fluctuations in synthesis conditions, leading to defects and disorder in the crystal structure, which affect the emission characteristics.

Innovation Solution

A core shell particle configuration with a core containing a Group III element and a Group V element, surrounded by multiple shell layers, where the molar ratio of silicon to the Group III element is 3.1 or less, as detected by X-ray photoelectron spectroscopy, is used, along with specific synthesis steps in inert gas atmospheres to control the crystal structure and reduce defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional synthesis methods are used without strict control of synthesis conditions, then the synthesis process is simple and easy to perform, but the luminous efficacy fluctuates and emission half-width becomes wide due to defects and disorder in crystal structure

Engineering Contradiction:
Improveluminous efficacyVSAvoidsynthesis process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by precisely controlling synthesis temperature, reaction time, and precursor ratios to achieve consistent high luminous efficacy. The core shell particle synthesis uses specific temperature ranges and time durations to ensure uniform crystal structure formation, resolving the fluctuation in luminous efficacy while maintaining a manageable synthesis process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs an inert atmosphere during synthesis to prevent oxidation and contamination of the core shell particles. This creates a controlled environment that ensures consistent crystal structure formation and high luminous efficacy without requiring overly complex synthesis procedures, thus improving reliability while keeping the process feasible.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Manufacturing precision

If conventional synthesis methods are used without strict control of synthesis conditions, then the synthesis process is simple and easy to perform, but the emission half-width becomes wide due to defects and disorder in crystal structure

Engineering Contradiction:
Improveemission half-widthVSAvoidsynthesis process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses parameter changes by optimizing synthesis temperature, reaction time, and precursor ratios to achieve narrow emission half-width. The controlled synthesis conditions ensure uniform crystal structure and consistent particle size, which directly narrow the emission half-width while keeping the synthesis process manageable through systematic parameter control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary action by pre-mixing precursors and preparing the synthesis environment before the actual reaction. This ensures that all conditions are optimized before particle formation begins, leading to uniform crystal structures and narrow emission half-width without requiring complex in-process adjustments.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If core shell particles are synthesized without controlling silicon content, then the synthesis process is simpler, but the luminous efficacy and emission characteristics are significantly affected by uncontrolled defects

Engineering Contradiction:
Improveluminous efficacyVSAvoidcrystal structure uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by controlling silicon content within specific ranges during synthesis. This precise control of compositional parameters ensures uniform crystal structure formation and high luminous efficacy, resolving the contradiction between reliability and manufacturing precision through systematic parameter optimization.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs feedback by monitoring and adjusting synthesis conditions based on observed particle characteristics. This ensures that silicon content and other parameters remain within optimal ranges, maintaining consistent crystal structure uniformity and high luminous efficacy through continuous process control.

Inventive Principle:
Principle #23Feedback

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

This configuration enhances luminous efficacy and narrows the emission half-width, improving the uniformity of the particle diameter and reducing defects, resulting in improved emission characteristics.

Implementation Method 1

at least silicon is detected by X-ray photoelectron spectroscopy analysis, and a molar ratio of the silicon to the Group III element contained in the core, which is acquired by X-ray photoelectron spectroscopy analysis, is 3.1 or less

Methodology Applied
Scientific EffectX-ray photoelectron spectroscopy: Photoelectric Effect

Data Source

PatentUS10519369B2Core shell particles, method for producing core shell particles, and film
Publication Date: 2019.12.31 FUJIFILM CORP

AI summary

An object of the present invention is to provide a core shell particle having high luminous efficacy and a narrow emission half-width; a method of producing the same; and a film formed of the core shell particle. The core shell particle of the present invention includes: a core which contains a Group III element and a Group V element; a first shell which covers at least a part of a surface of the core; a second shell which covers at least a part of the first shell; and a coordination molecule in at least a part of an outermost surface, in which at least silicon is detected by X-ray photoelectron spectroscopy analysis, and a molar ratio of the silicon to the Group III element contained in the core, which is acquired by X-ray photoelectron spectroscopy analysis, is 3.1 or less.