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GB/T 24370-2021 English PDF (GBT24370-2021)
GB/T 24370-2021 English PDF (GBT24370-2021)
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GB/T 24370-2021: Nanotechnologies -- Characterization of cadmium chalcogenide colloidal quantum dot -- UV-Vis absorption spectroscopy
GB/T 24370-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.040.50
CCS G 30
Replacing GB/T 24370-2009
Nanotechnologies - Characterization of Cadmium
Chalcogenide Colloidal Quantum Dot - UV-Vis Absorption
Spectroscopy
(ISO/TS 17466.2015, Use of UV-Vis absorption spectroscopy in the characterization
of cadmium chalcogenide colloidal quantum dots, MOD)
ISSUED ON. DECEMBER 31, 2021
IMPLEMENTED ON. JULY 1, 2022
Issued by. State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword... 3
Introduction... 6
1 Scope... 7
2 Normative References... 7
3 Terms and Definitions... 7
4 Abbreviations and Symbols... 8
5 Principle... 9
6 Sample Preparation... 12
7 Test Procedures... 12
8 Data Analysis and Result Expression... 13
9 Measurement Uncertainty... 13
10 Test Report... 14
Appendix A (informative) Example of Determining the Diameter of CdSe Quantum
Dots using UV-Vis Absorption Spectrum... 15
Appendix B (informative) Example of Determining Particle Concentration of CdSe
Quantum Dots in Dispersion Liquid... 23
Bibliography... 27
Nanotechnologies - Characterization of Cadmium
Chalcogenide Colloidal Quantum Dot - UV-Vis Absorption
Spectroscopy
1 Scope
This Standard provides a method for evaluating the diameter and particle concentration of
monodisperse cadmium chalcogenide (CdTe, CdSe and CdS) colloidal quantum dots using UV-
Vis absorption spectroscopy.
This document is applicable to the analysis of monodisperse spheroidal quantum dots. CdTe
with a diameter of 3.5 nm ~ 9 nm, CdSe with a diameter of 1 nm ~ 8 nm and CdS with a
diameter of 1 nm ~ 5.5 nm.
2 Normative References
This document does not have normative references.
3 Terms and Definitions
The following terms and definitions are applicable to this Standard.
3.1 quantum dot; QD
Crystalline nanoparticles that exbibit size-dependent properties due to the quantum
confinement effect of electronic states.
[source. GB/T 32269-2015, 4.7]
3.2 quantum confinement
When the size of the system is equivalent to the de Broglie wavelength of the particle, the
movement of the particle in one, two or three dimensions is restricted.
NOTE 1.the main characteristic dimensions that lead to quantum confinement are the de Broglie
wavelength, Fermi wavelength, mean free path, (exciton) Bohr radius or (exciton)
coherence length of the particle.
NOTE 2.the main manifestation of quantum confinement is that the electronic energy level is split
from the continuous state into discrete energy levels.
[source. ISO/TS 80004-12.2016, 2.5, modified]
3.3 first excitonic absorption
Light absorption generated when electrons in quantum dots transition from the ground state to
the first excitonic excited state.
4 Abbreviations and Symbols
4.1 Abbreviations
The following abbreviations are applicable to this document.
HDA. hexadecylamine
HRTEM. high resolution transmission electron microscopy
HWHM. half width at half maximum
OPA. n-octylphosphonate
PPA. P-P-(di-n-octyl) pyrophosphonate
QD. quantum dot
TEM. transmission electron microscopy
TOPO. trioctylphosphine oxide
UV-Vis. ultraviolet-visible
4.2 Symbols
The following symbols are applicable to this document.
A absorbance
c particle concentration
d particle diameter
E1s first exciton transition energy
I transmitted light intensity
I0 incident light intensity
l optical path
wavelength
E1s---the first exciton transition energy, expressed in (eV).
Formula (6) and Formula (8) come from Bibliography [5], and Formula (7) comes from
Bibliography [6]. The wavelength (unit. nm) and transition energy E (unit. eV) can be
converted through = 1,240/E.
6 Sample Preparation
The sample for the determination of the absorption spectrum shall be a uniform and stable
quantum dot dispersion liquid. Commercial quantum dots are usually synthesized through
organometallic chemical reaction solution method, and the surface of the quantum dots is coated
with organic molecules, such as. TOPO, OPA, PPA and HAD [7]. These organic molecules
prevent the quantum dots from agglomerating and maintain their dispersion. Typically, quantum
dots are small and can be well dispersed in a suitable solvent. It shall be ensured that the
prepared dispersion liquid is clear and transparent, and the solvent must be compatible with the
surface chemistry of the quantum dots and not interfere with the absorption spectrum of the
quantum dots. If the quantum dots are hydrophobic, then, non-polar solvents, such as. hexane
and chloroform shall be used. If the quantum dot surface becomes hydrophilic through ligand
exchange, then, polar solvents, for example, water, may be used.
In order to guarantee the applicability of the Beer-Lambert Law, a dilute dispersion liquid with
an absorbance (A) of the first excitonic absorption peak less than 1 shall be used for testing.
During the dilution process, quantum dot agglomeration caused by the shedding of ligand
molecules from the nanoparticle surface shall be avoided.
7 Test Procedures
7.1 UV-Vis Spectrophotometer
Use a calibrated spectrometer to cover UV-Vis wavelength. It is applicable to cadmium
chalcogenide colloidal quantum dots within the size range specified in this document, and the
spectrum range of the first excitonic absorption peak is 250 nm ~ 750 nm, depending on the
respective inorganic core material. Before the test, the UV-Vis spectrophotometer shall be
calibrated for wavelength and absorbance accuracy using standard substances (for example,
standard optical filters [8]).
7.2 Measurement Procedures of UV-Vis Absorption Spectrum
Refer to the instrument’s instruction manual and follow standard procedures for measuring
absorption spectra. Place the sample to be measured in a quartz cuvette, place the pure solvent
of dispersed quantum dots in another identical quartz cuvette as a reference for background
subtraction. At room temperature and normal pressure, carry out the test.
7.3 Recommended Test Parameters
The following test conditions should be used.
a) Wavelength range. 250 nm ~ 750 nm;
b) Step size. 0.5 nm or 1 nm;
c) Slit. 1 nm or 2 nm.
8 Data Analysis and Result Expression
8.1 Quantum Dot Size Estimation
Record the wavelength and absorbance at the maximum absorption point of the first excitonic
absorption peak. Within the applicable size range of the formula, utilize the Formula in 5.4 and
the recorded wavelength at the first excitonic absorption peak to calculate the average diameter
d.
NOTE. the Formula is applicable to quantum dots 3.5 nm ~ 9 nm CdTe, 1 nm ~ 8 nm CdSe and 1
nm ~ 5.5 nm CdS.
8.2 Estimation of Quantum Dot Particle Concentration
The procedures of calculating the particle concentration of quantum dot samples are as follows.
a) In accordance with the steps described in 8.1, measure the average particle diameter
d;
b) In accordance with Formula (6), Formula (7) and Formula (8), calculate the molar
extinction coefficient of the quantum dot dispersion liquid;
c) If necessary, in accordance with Formula (5), normalize the peak absorbance;
d) In accordance with the Beer-Lambert Formula [Formula (4)], calculate the particle
concentration c of t...
Get QUOTATION in 1-minute: Click GB/T 24370-2021
Historical versions: GB/T 24370-2021
Preview True-PDF (Reload/Scroll if blank)
GB/T 24370-2021: Nanotechnologies -- Characterization of cadmium chalcogenide colloidal quantum dot -- UV-Vis absorption spectroscopy
GB/T 24370-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.040.50
CCS G 30
Replacing GB/T 24370-2009
Nanotechnologies - Characterization of Cadmium
Chalcogenide Colloidal Quantum Dot - UV-Vis Absorption
Spectroscopy
(ISO/TS 17466.2015, Use of UV-Vis absorption spectroscopy in the characterization
of cadmium chalcogenide colloidal quantum dots, MOD)
ISSUED ON. DECEMBER 31, 2021
IMPLEMENTED ON. JULY 1, 2022
Issued by. State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword... 3
Introduction... 6
1 Scope... 7
2 Normative References... 7
3 Terms and Definitions... 7
4 Abbreviations and Symbols... 8
5 Principle... 9
6 Sample Preparation... 12
7 Test Procedures... 12
8 Data Analysis and Result Expression... 13
9 Measurement Uncertainty... 13
10 Test Report... 14
Appendix A (informative) Example of Determining the Diameter of CdSe Quantum
Dots using UV-Vis Absorption Spectrum... 15
Appendix B (informative) Example of Determining Particle Concentration of CdSe
Quantum Dots in Dispersion Liquid... 23
Bibliography... 27
Nanotechnologies - Characterization of Cadmium
Chalcogenide Colloidal Quantum Dot - UV-Vis Absorption
Spectroscopy
1 Scope
This Standard provides a method for evaluating the diameter and particle concentration of
monodisperse cadmium chalcogenide (CdTe, CdSe and CdS) colloidal quantum dots using UV-
Vis absorption spectroscopy.
This document is applicable to the analysis of monodisperse spheroidal quantum dots. CdTe
with a diameter of 3.5 nm ~ 9 nm, CdSe with a diameter of 1 nm ~ 8 nm and CdS with a
diameter of 1 nm ~ 5.5 nm.
2 Normative References
This document does not have normative references.
3 Terms and Definitions
The following terms and definitions are applicable to this Standard.
3.1 quantum dot; QD
Crystalline nanoparticles that exbibit size-dependent properties due to the quantum
confinement effect of electronic states.
[source. GB/T 32269-2015, 4.7]
3.2 quantum confinement
When the size of the system is equivalent to the de Broglie wavelength of the particle, the
movement of the particle in one, two or three dimensions is restricted.
NOTE 1.the main characteristic dimensions that lead to quantum confinement are the de Broglie
wavelength, Fermi wavelength, mean free path, (exciton) Bohr radius or (exciton)
coherence length of the particle.
NOTE 2.the main manifestation of quantum confinement is that the electronic energy level is split
from the continuous state into discrete energy levels.
[source. ISO/TS 80004-12.2016, 2.5, modified]
3.3 first excitonic absorption
Light absorption generated when electrons in quantum dots transition from the ground state to
the first excitonic excited state.
4 Abbreviations and Symbols
4.1 Abbreviations
The following abbreviations are applicable to this document.
HDA. hexadecylamine
HRTEM. high resolution transmission electron microscopy
HWHM. half width at half maximum
OPA. n-octylphosphonate
PPA. P-P-(di-n-octyl) pyrophosphonate
QD. quantum dot
TEM. transmission electron microscopy
TOPO. trioctylphosphine oxide
UV-Vis. ultraviolet-visible
4.2 Symbols
The following symbols are applicable to this document.
A absorbance
c particle concentration
d particle diameter
E1s first exciton transition energy
I transmitted light intensity
I0 incident light intensity
l optical path
wavelength
E1s---the first exciton transition energy, expressed in (eV).
Formula (6) and Formula (8) come from Bibliography [5], and Formula (7) comes from
Bibliography [6]. The wavelength (unit. nm) and transition energy E (unit. eV) can be
converted through = 1,240/E.
6 Sample Preparation
The sample for the determination of the absorption spectrum shall be a uniform and stable
quantum dot dispersion liquid. Commercial quantum dots are usually synthesized through
organometallic chemical reaction solution method, and the surface of the quantum dots is coated
with organic molecules, such as. TOPO, OPA, PPA and HAD [7]. These organic molecules
prevent the quantum dots from agglomerating and maintain their dispersion. Typically, quantum
dots are small and can be well dispersed in a suitable solvent. It shall be ensured that the
prepared dispersion liquid is clear and transparent, and the solvent must be compatible with the
surface chemistry of the quantum dots and not interfere with the absorption spectrum of the
quantum dots. If the quantum dots are hydrophobic, then, non-polar solvents, such as. hexane
and chloroform shall be used. If the quantum dot surface becomes hydrophilic through ligand
exchange, then, polar solvents, for example, water, may be used.
In order to guarantee the applicability of the Beer-Lambert Law, a dilute dispersion liquid with
an absorbance (A) of the first excitonic absorption peak less than 1 shall be used for testing.
During the dilution process, quantum dot agglomeration caused by the shedding of ligand
molecules from the nanoparticle surface shall be avoided.
7 Test Procedures
7.1 UV-Vis Spectrophotometer
Use a calibrated spectrometer to cover UV-Vis wavelength. It is applicable to cadmium
chalcogenide colloidal quantum dots within the size range specified in this document, and the
spectrum range of the first excitonic absorption peak is 250 nm ~ 750 nm, depending on the
respective inorganic core material. Before the test, the UV-Vis spectrophotometer shall be
calibrated for wavelength and absorbance accuracy using standard substances (for example,
standard optical filters [8]).
7.2 Measurement Procedures of UV-Vis Absorption Spectrum
Refer to the instrument’s instruction manual and follow standard procedures for measuring
absorption spectra. Place the sample to be measured in a quartz cuvette, place the pure solvent
of dispersed quantum dots in another identical quartz cuvette as a reference for background
subtraction. At room temperature and normal pressure, carry out the test.
7.3 Recommended Test Parameters
The following test conditions should be used.
a) Wavelength range. 250 nm ~ 750 nm;
b) Step size. 0.5 nm or 1 nm;
c) Slit. 1 nm or 2 nm.
8 Data Analysis and Result Expression
8.1 Quantum Dot Size Estimation
Record the wavelength and absorbance at the maximum absorption point of the first excitonic
absorption peak. Within the applicable size range of the formula, utilize the Formula in 5.4 and
the recorded wavelength at the first excitonic absorption peak to calculate the average diameter
d.
NOTE. the Formula is applicable to quantum dots 3.5 nm ~ 9 nm CdTe, 1 nm ~ 8 nm CdSe and 1
nm ~ 5.5 nm CdS.
8.2 Estimation of Quantum Dot Particle Concentration
The procedures of calculating the particle concentration of quantum dot samples are as follows.
a) In accordance with the steps described in 8.1, measure the average particle diameter
d;
b) In accordance with Formula (6), Formula (7) and Formula (8), calculate the molar
extinction coefficient of the quantum dot dispersion liquid;
c) If necessary, in accordance with Formula (5), normalize the peak absorbance;
d) In accordance with the Beer-Lambert Formula [Formula (4)], calculate the particle
concentration c of t...
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