ISO 20351:2024
(Main)Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for optical properties of ceramic phosphors for white light-emitting diodes using an integrating sphere
Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for optical properties of ceramic phosphors for white light-emitting diodes using an integrating sphere
This document specifies test methods for the use of an integrating sphere to measure the optical properties of ceramic phosphor powders, which are used in white light-emitting diodes (LEDs) and emit visible light when excited by UV or blue light. This document specifies an absolute method to measure internal quantum efficiency and a substitution method to measure external quantum efficiency and absorptance. The substitution method uses reference materials whose external quantum efficiency and absorptance have been obtained in accordance with ISO 23946.
Titre manque
General Information
Relations
Buy Standard
Standards Content (Sample)
International
Standard
ISO 20351
Second edition
Fine ceramics (advanced ceramics,
2024-10
advanced technical ceramics) —
Test method for optical properties
of ceramic phosphors for white
light-emitting diodes using an
integrating sphere
Reference number
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Measurement apparatus . 2
4.1 Apparatus configuration .2
4.2 Light source unit .4
4.3 Sample unit .4
4.3.1 Cell .4
4.3.2 White diffuser or reference cell .4
4.3.3 Integrating sphere .4
4.4 Detection unit .5
4.4.1 Directing optical system .5
4.4.2 Spectrometer and detector .5
4.4.3 Amplifier .5
4.5 Signal and data processing unit .5
5 Calibration, inspection and maintenance of measurement apparatus . 5
5.1 General .5
5.2 Wavelength calibration of light source unit .5
5.3 Cells and cover glasses .5
5.4 Integrating sphere walls and white diffusers .5
5.5 Wavelength calibration of detection unit .5
5.6 Spectral responsivity correction .6
6 Samples . 6
6.1 Reference material .6
6.2 Storage and pre-processing .6
6.3 Filling cells with samples .6
7 Procedure, calculation and report for absolute measurement . 6
7.1 Measurement method .6
7.1.1 Measurement environment .6
7.1.2 Light spectrum without phosphor sample .7
7.1.3 Light spectrum with phosphor sample .7
7.2 Calculations .7
7.2.1 Conversion to photon-number-based spectra .7
7.2.2 Fluorescence spectrum .8
7.2.3 Internal quantum efficiency .8
7.3 Test report .8
8 Procedure, calculation and report for substitution measurement . 9
8.1 Measurement procedures .9
8.1.1 Measurement environment .9
8.1.2 Spectrometer setup for substitution measurement .9
8.1.3 Measurement for reference material .10
8.1.4 Measurement for phosphor material under test .10
8.2 Calculation .10
8.2.1 Spectral responsivity correction .10
8.2.2 Conversion to photon number-based spectral distribution .10
8.2.3 Calculation of scattered light and fluorescence photon numbers .11
8.2.4 External quantum efficiency . 12
8.2.5 Absorptance . 12
8.3 Test report . 12
iii
Bibliography . 14
iv
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO 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, ISO 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
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.
This second edition cancels and replaces the first edition (ISO 20351:2017), which has been technically
revised.
The main changes are as follows:
— scope of the document is expanded by additionally implementing the reference material-based
substitution measurement method to measure external quantum efficiency and absorptance.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
Introduction
White light-emitting diode (LED) based solid-state lighting (SSL) has been widely used for a variety of
applications as alternatives for incandescent and fluorescent lamps. Initially, white LEDs (comprising blue
LEDs and yellow phosphors) became popular as backlight sources for small-size liquid-crystal displays
(LCDs) used in mobile phones and digital cameras. These were followed by white LEDs (consisting of
blue LEDs combined with green and red phosphors) applied to backlight sources for large-area LCDs.
Subsequently, LED lamps were commercialised for general lighting, replacing conventional luminaires and
capitalising on their advantages, such as compactness, high luminous efficiency, high
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.