GB/Z 37664.2-2025Nanomanufacturing - Key control characteristics - Luminescent nanoparticles - Part 2: Determination of mass of quantum dot in dispersion (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document is Part 2 of "Key Control Properties of Luminescent Nanomaterials in Nanofabrication," specifically the section on "Key Control Properties of Luminescent Nanomaterials in Nanofabrication." The journal *Nanomaterials* has published the following sections.

---Part 1: Quantum Efficiency (GB/T 37664.1-2019);

---Part 3: Measurement of fluorescence lifetime of semiconductor quantum dots using time-correlated single-photon counting techniques (GB /Z 37664.3-2025).

This document is equivalent to IEC TS62607-3-2:2017 "Key control characteristics of nanofabrication - Part 3-2.Luminescent nanomaterials".

"Quantum Dot Mass Measurement in Dispersions". The document type has been changed from an IEC technical specification to a national standardization guidance document in my country.

document.

The following minimal editorial changes have been made to this document.

---The standard title has been changed to "Key Control Properties of Nanofabrication. Luminescent Nanomaterials Part 2: Quantum Dot Mass in Dispersions".

Measurement";

---The word "pan" (pallet) is translated as "crucible" according to domestic usage;

---The units of MCn and MCI in the mass concentrations measured by the relative absorption method in section 7.2 have been corrected;

---Added a note to section 6.1 General Requirements. Ultrapure N2 refers to N2 with a purity of 99.9999%.

---An errata has been made regarding the mass calculation data of quantum dots in the dispersion in Appendix A;

---Added examples (absorbance range 0.2~0.8) and figures in Appendix B.

Introduction

Quantum dots are nanoscale crystals of semiconductor materials, typically ranging from 2 nm to 15 nm in size, but not limited to this range.

The quantum confinement effect gives quantum dots specific light absorption and emission properties. There are various methods for synthesizing quantum dots; colloidal synthesis is one of the most common methods.

The most common method is to synthesize quantum dots in the presence of stable ligands to maintain the stability of the quantum dot crystal.

The ligands remain after purification and are an important component in maintaining the dispersion and stability of quantum dots, and can also affect their optical properties.

Typically, quantum dot samples are provided in the form of a stable dispersion rather than a dry powder. This document specifies a method for measuring quantum dots in a dispersion.

Quality methods.

In addition to semiconductor materials and their tightly bound stable ligands, quantum dot dispersions may also contain unreacted precursors, precursors, and other precursors.

Byproducts and free ligands of the substance. Because impurities are difficult to remove and their content is difficult to measure, the mass of dried samples is unsuitable for measurement purposes.

Sub-dot quality. Instead, a method is chosen to remove impurities while keeping the semiconductor material intact.

break down.

One method to volatilize or decompose impurities and surfactant ligands is to heat the quantum dot sample to a high temperature (650°C). This process involves heating the quantum dot sample to a high temperature (650°C).

Heating samples to such high temperatures typically destroys quantum dot samples; therefore, this analytical method requires a small portion that is representative of the entire sample.

Execution is carried out on a case-by-case basis.

Thermogravimetric analysis (TGA) is a convenient method that can accurately measure the temperature of small samples (10 mg to 50 mg) heated to high temperatures in a N2 or O2 atmosphere.

Mass loss at temperature. The general procedure involves adding a certain amount of dispersion to the thermogravimetric analysis (TGA) crucible, removing the dispersing solvent, and then heating the TGA crucible to [temperature missing].

650°C. The remaining mass mainly consists of inorganic content from the quantum dot material. Compared to instruments such as inductively coupled plasma mass spectrometry, thermogravimetric analysis...

It is convenient and universal, and can directly measure the inorganic mass of quantum dot mixtures.

The following are the sources of error based on thermogravimetric analysis.

---In a nitrogen atmosphere, impurities may not volatilize but instead decompose and transform into graphite or other non-volatile products. This will lead to The measured mass is greater than the mass of the semiconductor material, while heating the organic precursor to 650°C typically yields only a small amount of residue.

Mass (< 2% of the initial mass).

---Under an O2 atmosphere, heating the sample may lead to a mass increase due to the oxidation of metals and chalcogenides. To avoid this...

In case of complications, the sample is usually heated under a N2 atmosphere.

---Residue may remain when inorganic impurities are heated. These impurities (such as carboxylates and phosphates) are generally insoluble in commonly used dispersible solutions.

Agents (such as hexane, toluene), if a suitable solvent is used, the concentration of these impurities in the dispersion is expected to be low, unless they are...

Dissolution of quantum dot materials. If a solvent capable of dispersing potential impurities is used, additional analysis may be required to measure inorganic impurities.

The content. For safety reasons, this method is not suitable for testing substances containing perchlorate, as this could cause an explosion.

---Closely bound surface ligands may not completely decompose under the test conditions. Surface ligands may transform into carbides (such as silica).

(Ink) rather than volatiles. In this case, the remaining ligand mass will be included in the mass calculation.

Depending on the chemical composition and heating conditions, certain metals or main group elements may volatilize from quantum dots. In this case, then...

The maximum heating temperature was varied. These methods were applied to quantum dot samples containing CdSe, CdS, ZnS, InP, InAs, PbS, and mixtures thereof.

Effective application in powders.

This document provides a method for measuring the mass of colloidal quantum dot dispersions after removing or decomposing impurities. This method can minimize the reduction of impurities.

Less frequently encountered potential errors.

The national standard "Key Control Properties of Luminescent Nanomaterials in Nanomanufacturing" aims to regulate and standardize luminescent nanomaterials.

It consists of three parts.

---Part 1: Quantum Efficiency. The purpose is to outline the steps and precautions to be taken when reproducibly measuring the quantum efficiency of luminescent nanomaterials.

Standardization of items.

---Part 2: Measurement of quantum dot mass in dispersions. The purpose is to define the methods and phases for measuring the mass of quantum dots in quantum dot dispersions.

The corresponding operating procedures.

---Part 3: Measurement of fluorescence lifetime of semiconductor quantum dots using time-correlated single-photon counting techniques. The aim is to provide a method for...

A method for measuring the fluorescence lifetime of semiconductor quantum dots using time-correlated single-photon counting technology.

Key Control Properties of Nanomaterials in Nanofabrication Part 2: Measurement of quantum dot mass in dispersion

1 Scope

This document describes a method for measuring the mass of quantum dots in a quantum dot dispersion after removing impurities and surfactant ligands through high-temperature heating.

Methods for determining mass concentration.

2 Normative references

This document has no normative references.

Note: The documents listed in the references are helpful for the application of this document.

3 Terms and Definitions

The following terms and definitions apply to this document.

4 Devices

The main equipment should include the following functions.

---A hot plate, hot air gun, or other heating device used to remove dispersing solvents.

---A vacuum line for removing the dispersion solvent and a chamber for housing the thermogravimetric crucible.

---A gas stream used to remove the dispersing solvent.

---A gas stream of inert gas (such as N2, Ar, He) at a moderate pressure (typically < 3.45 kPa) is used to purge the surface of the dispersing solvent.

The flow rate should be sufficient to allow the solvent to evaporate, but not too high to avoid the sample overflowing from the crucible, which would invalidate the measurement.

---Thermogravimetric analysis was performed using a calibrated thermogravimetric analyzer.

---Thermogravimetric crucible, typically a small container, is designed to match the temperature range and design of the thermogravimetric analysis instrument used.

--- Syringe or calibrated pipette.

5 Sample Preparation

Zero the mass of the thermogravimetric crucible. Accurately measure the quantum dot dispersion using a syringe or pipette, and record the sample volume (VS).