Semiconductor Nanoparticle Ligand Exchange for Emission Efficiency

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Solution Overview

Problem

Semiconductor nanoparticles' emission efficiency and durability are compromised by the type of ligand used in ligand exchange, leading to instability, especially when exposed to infrared rays.

Innovation Solution

A semiconductor nanoparticle with specific compositions and ligand configurations, including the detection of oxygen, zinc, and sulfur by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and the coordination of carboxyl and mercapto groups, is developed to enhance emission efficiency and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ligand exchange is performed to improve electrical conductivity, then electrical conductivity is improved, but emission efficiency deteriorates

Engineering Contradiction:
Improveelectrical conductivityVSAvoidemission efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by carefully controlling the ligand exchange process parameters, including the type of ligand used (carboxyl group-containing or mercapto group-containing), the exchange ratio, and processing conditions. This allows optimization of both electrical conductivity and emission efficiency by adjusting these parameters to achieve the desired balance between conductivity improvement and emission efficiency preservation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If ligand exchange is performed to improve electrical conductivity, then electrical conductivity is improved, but durability with respect to infrared rays deteriorates

Engineering Contradiction:
Improveelectrical conductivityVSAvoiddurability with respect to infrared rays
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent uses parameter changes by selecting specific ligand types (carboxyl group-containing or mercapto group-containing) and controlling the ligand exchange ratio to maintain durability with respect to infrared rays while improving electrical conductivity. The careful selection of ligand parameters ensures that the semiconductor nanoparticle's stability under infrared exposure is preserved.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If shorter ligand molecules are used to improve electrical conductivity, then electrical conductivity is improved, but emission efficiency deteriorates

Engineering Contradiction:
Improveelectrical conductivityVSAvoidemission efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

Instead of simply using shorter ligand molecules, the patent changes the parameter of ligand type to carboxyl group-containing or mercapto group-containing ligands. This parameter change allows for improved electrical conductivity through better charge transport while the specific chemical groups maintain strong binding to the semiconductor nanoparticle surface, preserving emission efficiency.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If shorter ligand molecules are used to improve electrical conductivity, then electrical conductivity is improved, but durability with respect to infrared rays deteriorates

Engineering Contradiction:
Improveelectrical conductivityVSAvoiddurability with respect to infrared rays
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by using carboxyl group-containing or mercapto group-containing ligands with controlled exchange ratios. These specific ligand parameters provide both improved electrical conductivity through enhanced charge transport and maintained durability with respect to infrared rays due to strong surface binding and stability of the ligand-semiconductor interface.

Inventive Principle:
Principle #35Parameter changes

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 nanoparticles exhibit high emission efficiency and excellent durability, maintaining performance even after exposure to infrared radiation, with improved ligand exchange ratios and configurations optimizing surface reinforcement.

Implementation Method 1

oxygen, zinc, and sulfur are detected by X-ray photoelectron spectroscopy analysis

Methodology Applied
Scientific EffectX-ray photoelectron spectroscopy: X-Ray

Implementation Method 2

a peak (ICH3) which is derived from a hydrocarbon group and present in a range of 2800 cm−1 to 3000 cm−1 and a peak (ICOO) which is derived from COO− and present in a range of 1400 cm−1 to 1600 cm−1 are detected by Fourier transform infrared spectroscopy analysis

Methodology Applied
Scientific EffectFourier transform infrared spectroscopy:

Implementation Method 3

the coordination of carboxyl and mercapto groups, is developed to enhance emission efficiency and durability

Methodology Applied
Scientific EffectLigand coordination: Chemical Bonding

Implementation Method 4

the semiconductor nanoparticles exhibit high emission efficiency and excellent durability, maintaining performance even after exposure to infrared radiation

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Data Source

PatentUS10640703B2Semiconductor nanoparticle, dispersion liquid, film, and method of producing semiconductor nanoparticle
Publication Date: 2020.05.05 FUJIFILM CORP

AI summary

An object of the present invention is to provide a semiconductor nanoparticle having high emission efficiency and excellent durability; a method of producing the same; and a dispersion liquid and a film obtained by using a semiconductor nanoparticle. The semiconductor nanoparticle of the present invention is a semiconductor nanoparticle in which oxygen, zinc, and sulfur are detected by X-ray photoelectron spectroscopy analysis and a peak (ICH3) which is derived from a hydrocarbon group and present in a range of 2800 cm−1 to 3000 cm−1 and a peak (ICOO) which is derived from COO− and present in a range of 1400 cm−1 to 1600 cm−1 are detected by Fourier transform infrared spectroscopy analysis.