IEC TS 62607-6-33:2025

IEC TS 62607-6-33 ®
Edition 1.0 2025-10
TECHNICAL
SPECIFICATION
Nanomanufacturing - Key control characteristics -
Part 6-33: Graphene-related products - Defect density of graphene: electron
energy loss spectroscopy
ICS 07.120  ISBN 978-2-8327-0795-1

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either
IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC copyright
or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local
IEC member National Committee for further information.

IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - IEC Products & Services Portal - products.iec.ch
webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the
The advanced search enables to find IEC publications by a
publications previews, graphical symbols and the glossary.
variety of criteria (reference number, text, technical With a subscription you will always have access to up to date
committee, …). It also gives information on projects, content tailored to your needs.
replaced and withdrawn publications.

Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English
details all new publications released. Available online and and French, with equivalent terms in 25 additional languages.
once a month by email. Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer
Service Centre: sales@iec.ch.
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Environmental condition . 10
5 Sample . 11
5.1 General . 11
5.2 Preparation of TEM sample for graphene grown by CVD method . 11
5.3 Sample storage . 12
6 Measurement principle . 12
6.1 General . 12
6.2 Data interpretation . 13
7 Measurement procedure . 14
7.1 General . 14
7.2 Detector . 14
7.3 Description of the measurement procedure . 15
7.3.1 Transmission electron microscope alignment . 15
7.3.2 Measurement . 15
7.4 Defect density determination . 16
7.5 Report of the results . 17
Annex A (informative) Format of the test report . 18
Annex B (informative) Sampling plan . 20
B.1 General . 20
B.2 Sampling plan depending on substrate (product type) geometry . 20
B.2.1 Circular substrates . 20
B.2.2 Square substrates . 21
B.2.3 Irregular shaped substrates . 22
B.3 Sampling plan depending on TEM grid geometry . 23
B.3.1 General . 23
B.3.2 300 mesh TEM grid . 24
Annex C (informative) Determination of boundary for graphene and defects . 25
Annex D (informative) Applications, worked examples: Defect density measurement of
graphene grown on Cu substrate by CVD . 29
Bibliography . 33

Figure 1 – Preparation of TEM sample for graphene grown by CVD method. 12
Figure 2 – Electron energy loss spectra of pristine (top) and defective (bottom) graphene . 13
Figure 3 – Schematic diagram of defect density measurements by EELS . 14
Figure 4 – Schematic diagram of π*/σ* amplitude ratio calculation by spectral image . 16
Figure B.1 – Schematic of sample plan for circular substrates (in accordance with
IEC TS 62607-6-11:2022) . 21
Figure B.2 – Schematic of sample plan for square substrates (in accordance with
IEC TS 62607-6-11:2022) . 22
Figure B.3 – Example sampling plan for irregular sample (in accordance with
IEC TS 62607-6-11:2022) . 23
Figure B.4 – Schematic of sample plan for 300 mesh TEM grid . 24
Figure C.1 – π*/σ* amplitude map defined as a number or image . 27
Figure C.2 – Comparison of spectral backgrounds of graphene, defects, and boundary
values (π*/σ* amplitude) in the high-loss energy region . 28
Figure D.1 – Preparation of TEM specimens of CVD-grown graphene by direct transfer . 29
Figure D.2 – Measurement of defect density of graphene by STEM-EELS . 30

Table A.1 – Product identification (in accordance with the relevant blank detail
specification) . 18
Table A.2 – General material description (in accordance with the relevant blank detail
specification) . 18
Table A.3 – Measurement related information . 19
Table B.1 – Sampling plan for circular substrates (in accordance with
IEC TS 62607-6-11:2022) . 21
Table B.2 – Sampling plan for square sample (in accordance with IEC TS 62607-6-
11:2022) . 22
Table B.3 – Sampling plan for 300 mesh TEM grid . 24
Table D.1 – Product identification . 31
Table D.2 – General material description . 31
Table D.3 – Measurement related information . 31

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Nanomanufacturing - Key control characteristics -
Part 6-33: Graphene-related products - Defect density of graphene: electron
energy loss spectroscopy
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all
national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-
operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition
to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly
Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate
in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also
participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO)
in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all interested
IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services
carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or other
damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising
out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s).
IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof.
As of the date of publication of this document, IEC had not received notice of (a) patent(s), which may be required
to implement this document. However, implementers are cautioned that this may not represent the latest information,
which may be obtained from the patent database available at https://patents.iec.ch. IEC shall not be held responsible
for identifying any or all such patent rights.
IEC TS 62607-6-33 has been prepared by IEC technical committee 113: Nanotechnology for
electrotechnical products and systems. It is a Technical Specification.
The text of this Technical Specification is based on the following documents:
Draft Report on voting
113/913/DTS 113/932/RVDTS
Full information on the voting for its approval can be found in the report on voting indicated in the
above table.
The language used for the development of this Technical Specification is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available at
www.iec.ch/members_experts/refdocs. The main document types developed by IEC are described
in greater detail at www.iec.ch/publications.
A list of all parts of the IEC TS 62607 series, published under the general title Nanomanufacturing
- Key control characteristics, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the specific
document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
INTRODUCTION
Quantitative and qualitative measurement of graphene defect is one of the most important factors
to determine the quality of graphene. This document presents an analytical method for measuring
local defect of graphene or graphene-related materials using scanning transmission electron
microscopy (STEM) with electron energy loss spectroscopy (EELS). The scanning capability used
in this method enables the defect distribution to be analysed, which can be used in determination
of graphene quality. This document will be strengthened and compensated by other methods, such
as Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), optical microscopy, etc., which
have already been standardized in IEC TC 113.
STEM-based EELS uses electron beams with sub-nanometre scale, which allows structural
observations within a highly localized area. Therefore, it is suitable for tracking important defect
information that occurs at the atomic scale. Unlike other macroscopic analytical tools (e.g. Raman
and XPS), the EELS method sets a clear boundary between graphene and defects that are induced
by lattice transformation, doping, and adatoms. Moreover, the method determines the classification
and quantity of defects including the number of holes and amorphous regions. These
characteristics would complement the existing standards for measuring the defect density in
graphene. Particularly, the advancements in STEM-EELS instruments, combined with large-scale
data processing technologies, can significantly enhance their complementarity with other
macroscopic analysis tools.
The electron energy structure of carbon atoms varies according to the irradiation direction of the
electron beam or the sample orientation with respect to electron beam. It can be detected mainly
through the change of π* and σ* peaks at the carbon K-edge. This tendency is apparent in the π*
2 2
peak, which also presents the sp bonding information. Since graphene is a single-layer sp hybrid
structure, the intensity ratio between π* and σ* peaks for an ideal graphene is 1:3, which is the
same for the π/σ bond ratio. Thus, graphene defects show different electron energy structure
compared to pristine graphene. The defect structure of graphene greatly affects the electrical and
chemical properties of graphene. Therefore, measuring the defect density of graphene is the key
to improving and optimizing its quality for the advancing industrial applications.

1 Scope
This part of IEC TS 62607 establishes a standardized method to determine the key control
characteristic
– defect density (%, nm )
of single layer graphene films by
– electron energy loss spectroscopy (EELS in transmission electron microscopy (TEM)).
This document outlines a method for quantitative measurement of defects in graphene at the
nanoscale.
The method specified in this document is applicable to single layer graphene acquired via chemical
vapour deposition (CVD), roll-to-roll production and exfoliated graphene flakes to estimate the
defect density.
In order to obtain reliable data, it is essential that the procedure is consistent for each specified
condition from the preparation of the TEM specimen to its observation. It is essential to maintain
the spatial resolution below 1 nm by alignment of the beam. The dispersion value, which covers
the entire energy loss near edge structure (ELNES) region of the carbon-K edge and maintains
the highest energy resolution corresponds to 0,1 eV/ch. Defects in graphene are determined by
2 2 3
measuring the spectral differences between sp hybridized and sp /sp hybridized atoms, which
are obtained by calculating the amplitude ratio of the π* and σ* orbital spectra.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
3.1
transmission electron microscopy
TEM
method that produces magnified images or diffraction patterns of the sample by an electron beam
which passes through the sample and interacts with it
[SOURCE: ISO/TS 80004-6:2021 [1], 4.5.6]
3.2
scanning transmission electron microscopy
STEM
method that produces magnified images or diffraction patterns of the sample by a finely focused
electron beam, scanned over the surface and which passes through the sample and interacts with
it
Note 1 to entry: Typically uses an electron beam with a diameter of less than 1 nm.
Note 2 to entry: Provides high-resolution imaging of the inner microstructure and the surface of a thin sample (or small
particles), as well as the possibility of chemical and structural characterization of micrometre and submicrometre domains
through evaluation of the electron energy loss spectra and the X-ray spectra, electron diffraction pattern.
[SOURCE: ISO/TS 80004-6:2021 [1], 4.5.7, modified - In Note 2 to entry, "the X-ray spectra and
the electron diffraction pattern" has been replaced with "the electron energy loss spectra and the
X-ray spectra, electron diffraction pattern".]
3.3
electron energy loss spectroscopy
EELS
method in which an electron spectrometer measures the energy spectrum of electrons from a
nominally monoenergetic source emitted after inelastic interactions with the sample, often
exhibiting peaks due to specific inelastic loss processes
[SOURCE: ISO/TS 80004-6:2021 [1], 5.14, modified - The notes to entry have been deleted.]
3.4
electron energy loss spectrum
energy spectrum of electrons from a nominally mono-energetic source emitted after inelastic
interactions with the sample, often exhibiting peaks due to specific inelastic loss processes
[SOURCE: ISO/TS 10797:2012 [2], 3.5, modified - Note 1 to entry has been deleted.]
3.5
energy loss near edge structure
ELNES
fine energy structure caused by electric dipole transitions from core-orbitals to unoccupied states
in the high-energy loss region of the selected elements in the sample

Note 1 to entry: In general, it is an electron energy structure within 50 eV of the conduction band.
3.6
spectrum image
image produced in scanning transmission electron microscope mode in which each pixel of the
image contains a spectrum
3.7
chemical vapour deposition
CVD
deposition of a solid material by chemical reaction of a gaseous precursor or mixture of precursors,
commonly initiated by heat on a substrate
[SOURCE: ISO/TS 80004-8:2013 [3], 7.2.3]
3.8
roll-to-roll production
R2R production
<2D material> CVD growth of 2D material(s) upon a continuous substrate that is processed as a
rolled sheet, often including transfer of 2D material(s) to a separate substrate
[SOURCE: ISO/TS 80004-13:2024[4], 3.2.1.6]
3.9
graphene
graphene layer
single-layer graphene
monolayer graphene
1LG
single layer of carbon atoms with each atom bound to three neighbours in a honeycomb structure
Note 1 to entry: It is an important building block of many carbon nano-objects.
Note 2 to entry: As graphene is a single layer, it is also sometimes called monolayer graphene or single-layer graphene
and abbreviated as 1LG to distinguish it from bilayer graphene (2LG) and few-layered graphene (FLG).
Note 3 to entry: Graphene has edges and can have defects and grain boundaries where the bonding is disrupted.
[SOURCE: ISO/TS 80004-13:2024 [4], 3.1.2.1, modified - Note 4 to entry has been deleted.]
3.10
defect
<2D material> local deviation from the crystal lattice of a 2D material
[SOURCE: ISO/TS 80004-13:2024 [4], 3.4.1.1, modified - In the definition, "regularity in" has been
deleted.]
3.11
Stone-Wales defect
<2D material> crystallographic defect that involves the change of connectivity of two π-bonded
carbon atoms, leading to their rotation by 90° with respect to the midpoint of their bond, hence four
adjacent six-membered carbon rings are changed into two five-membered rings and two seven-
membered rings
[SOURCE: ISO/TS 80004-13:2024 [4], 3.4.1.20]
3.12
vacancy defect
<2D material> defect due to the absence of one or more atoms from a site normally occupied in
the lattice of a layer of 2D material
3.13
ad-atom defect
defect due to additional atoms present in the graphene surface layer, sp hybridized
amorphous structure of carbon atom or atoms
Note 1 to entry: Pristine graphene is ideally composed of a fully sp hybridized carbon lattice.
3.14
grain boundary
interface separating two or more grains with different crystallographic orientations
[SOURCE: ISO 4885:2018 [5], 3.95, modified - In the definition, "or more" has been added.]
3.15
planar defect
<2D material> defect occurring in the stacking sequence of the layers of a 2D material
Note 1 to entry: Includes both amorphous and multi-layered planes.
[SOURCE: ISO/TS 80004-13:2024 [4], 3.4.1.6, modified - Note 1 to entry has been added.]
3.16
defect density
number of defects per unit of product size
[SOURCE: ISO/IEC/IEEE 24765:2017 [6], 3.1082, modified - The example has been deleted.]
3.17
π* peak
peak exhibited by the 1 s → π* transitions and which has information about
the change and direction of the sp bonding structure.
Note 1 to entry: Since the π antibonding state corresponds to the out-of-plane bonding of sp bonding, it is paradoxically
more sensitive to changes in the sp bonding configurations.
Note 2 to entry: The π* peak is located at 285,2 eV.
3.18
σ* peak
peak exhibited by 1 s → σ* transitions and which is affected by the formation
of amorphous or nano-crystalline materials
Note 1 to entry: The σ* peak is located at 292,2 eV.
4 Environmental condition
The sample measurement in a transmission electron microscope is performed by detecting and
interpreting various signals generated by electron beam passing through a sample. In order for an
electron beam to be visualized as an interpretable image through an image medium such as a
screen, charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS)
detectors, the thickness of the sample should be thin enough to allow a sufficient number of
electrons passing through the sample. Graphene is a material with a thickness of a single layer of
atoms and has a thickness of 0,3 nm. Even with defects, graphene is intrinsically thin, so the
thickness of a single layer does not exceed the nanoscale.
As described, graphene itself is so thin that it is easily damaged under strong electron beam.
Hence, the acceleration voltage of TEM should be maintained below 80 kV, which is the threshold
for knock-on damage of graphene.
−4
Conventionally, a low pressure of 10 Pa or less is recommended to ensure that a mean free path
of electrons is maintained in the TEM column. Additionally, a pressure near a gun where the
−7 −9
electron beam oscillates should maintain an ultra-high vacuum of 10 to 10 Pa to prevent arc
discharge in the cathode. The vibration tolerance limit of the TEM chamber is 2 μm/s (10 Hz) or
less; also, the measurement interference due to vibration should be excluded.
5 Sample
5.1 General
The test sample is based on graphene synthesized by the CVD method or R2R production. The
TEM sampling locations for collecting information on the distribution of structural defects in
graphene across the test sample should follow one of the sampling plans provided in Annex B. If
plasma.
graphene is synthesized on both sides of the substrate, one side shall be removed using O
At this stage, place the side to be protected in contact with the PET film and secure the edges with
tape. By exposing only the backside to plasma in this manner, it is possible to effectively remove
graphene from one side of the substrate. The total size of the sample is 3 mm or more in diameter,
which is transferred to a 3 mm diameter TEM grid. In order to avoid the folding effect during the
transmission process, parts exceeding the TEM grid size should be separated.
5.2 Preparation of TEM sample for graphene grown by CVD method
In order to perform the TEM analysis of graphene grown by the CVD method, the transcription
process to the TEM grid is essential. The transferring process of TEM specimen shall be prepared
using the direct transfer (polymer-free) method [7] to minimize contamination and mechanical
damage to graphene.
The TEM preparation of graphene sample grown on a metal substrate by the CVD method is
presented below and illustrated in Figure 1.
a) Place the TEM grid with the amorphous-carbon layer side over the sample (the TEM grid uses
an Au grid to prevent it from reacting with acid).
b) Drop isopropyl alcohol (IPA) solution so that the surface of the TEM grid is completely covered.
c) After the IPA solution is completely evaporated, use an optical microscope to confirm adhesion
between the graphene and the TEM grid.
d) Leave the sample on the surface of an acid solution to etch the metal substrate.
e) After the metal is completely etched, remove any graphene that exceeds the TEM grid radius
and transfer the sample onto deionized (DI) water.
f) Rinse with DI water and, after six hours, transfer to an oven to dry.
g) Carry out heat treatment at 300 °C.
___________
Numbers in square brackets refer to the Bibliography.
Key
DI deionized
IPA isopropyl alcohol
Figure 1 – Preparation of TEM sample for graphene grown by CVD method
5.3 Sample storage
Any commercialized graphene includes some form of defects. Since the constant temperature and
humidity conditions of the graphene and the graphene defect structure are not the same, the
following general experimental and storage environmental conditions should be met.
a) Temperature: Target temperature ± 2 °C, r
...