IEC 60747-5-9:2019

Semiconductor devices - Part 5-9: Optoelectronic devices - Light emitting diodes - Test method of the internal quantum efficiency based on the temperature-dependent electroluminescence

IEC 60747-5-9:2019(E) specifies the measuring method of the internal quantum efficiency (IQE) of single light emitting diode (LED) chips or packages without phosphor. White LEDs for lighting applications are out of the scope of this document. This document utilizes the relative external quantum efficiencies (EQEs) measured at cryogenic temperatures and at an operating temperature, which is called temperature-dependent electroluminescence (TDEL). In order to identify the reference IQE of 100 %, the maximum values of the peak EQE are found by varying the environmental temperature and current.

General Information

• Status: Published
• Publication Date: 10-Dec-2019
• ICS: 31.080.99 - Other semiconductor devices
• Technical Committee: SC 47E - Discrete semiconductor devices
• Drafting Committee: WG 9 - TC 47/SC 47E/WG 9
• Current Stage: PPUB - Publication issued
• Start Date: 11-Dec-2019
• Completion Date: 02-Jan-2020

Overview

IEC 60747-5-9:2019 defines a standardized test method for measuring the internal quantum efficiency (IQE) of single LED chips or packages without phosphor using temperature-dependent electroluminescence (TDEL). The procedure converts measured radiant power into relative external quantum efficiency (EQE) across a range of ambient and cryogenic temperatures to identify the peak EQE (reference IQE = 100 %). White LEDs for lighting applications are out of scope.

Keywords: IEC 60747-5-9, IQE, internal quantum efficiency, TDEL, temperature-dependent electroluminescence, EQE, LED test method, cryogenic measurement

Key topics and technical requirements

• Scope and purpose

  • Measures IQE for single LED chips/packages without phosphor by analyzing relative EQE vs. current and temperature.
  • Uses cryogenic and operating temperature measurements (TDEL) to find peak EQE and establish reference IQE.

• Measurement principles

  • Radiant power versus forward current is measured at multiple temperatures from room temperature down to cryogenic range (< 200 K).
  • Relative EQE curves are derived from radiant power data; maximum peak EQE values across temperature/current identify the IQE reference.

• Environmental and equipment requirements

  • Default ambient measurement condition: (25 ± 3) °C in free air unless otherwise specified.
  • Relative humidity: 45 % to 85 % RH when not specified.
  • Cryostat recommended to reach ≤ 25 K for low-temperature characterization; a critical cryogenic temperature (Tc) is identified where peak EQE is maximal.
  • Instruments and setup reference: measurement equipment per IEC 60747-5-6:2016 (clause 6.1.2).

• Measurement sequence and reporting

  • Defined measurement setup (electrical drive, optical detection, cryostat), sequence to achieve thermal equilibrium, and checks for heat-related drift.
  • Test report content and annexed test examples provided in the standard to assist implementation.

Applications and users

• Who uses it

  • LED manufacturers and process engineers performing device characterization and yield optimization.
  • Semiconductor test laboratories and R&D teams measuring radiative efficiency and recombination performance.
  • Component validation teams assessing non-phosphor LED chips for automotive, display, signaling, and specialty lighting segments.

• Practical value

  • Provides a repeatable, internationally recognized method to quantify IQE and compare LEDs across batches and designs.
  • Useful for performance benchmarking, material and epitaxial process development, and failure analysis.

Related standards

• IEC 60747-5-6:2016 - referenced for measuring instruments and general optoelectronic device test requirements.
• IEC 60747 series - broader context for semiconductor device test and terminology.

For implementation, follow the measurement setup, thermal control, and reporting structure described in IEC 60747-5-9 to ensure consistent, reproducible IQE results using TDEL.

Standards Content (Sample)

IEC 60747-5-9 ®
Edition 1.0 2019-12
INTERNATIONAL
STANDARD
colour
inside
Semiconductor devices –
Part 5-9: Optoelectronic devices – Light emitting diodes – Test method of the
internal quantum efficiency based on the temperature-dependent
electroluminescence
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IEC 60747-5-9 ®
Edition 1.0 2019-12
INTERNATIONAL
STANDARD
colour
inside
Semiconductor devices –
Part 5-9: Optoelectronic devices – Light emitting diodes – Test method of the

internal quantum efficiency based on the temperature-dependent

electroluminescence
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.080.99 ISBN 978-2-8322-7656-3

– 2 – IEC 60747-5-9:2019 © IEC:2019
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviated terms . 5
3.1 Terms and definitions . 5
3.2 Abbreviated terms . 7
4 Measuring methods . 7
4.1 Basic requirements . 7
4.1.1 Measuring conditions . 7
4.1.2 Measuring instruments and equipment . 7
4.2 Purpose . 7
4.3 Measurement . 8
4.3.1 Measurement setup . 8
4.3.2 Measurement principle. 8
4.3.3 Measurement sequence . 11
5 Test report . 12
Annex A (informative) Test examples . 13
A.1 Test example (category 1) . 13
A.2 Test example (category 2) . 16
Bibliography . 19

Figure 1 – Example of the measurement setup with the TDEL . 8
Figure 2 – Schematic diagram of radiant power as a function of forward current at
various temperatures . 9
Figure 3 – Examples of relative EQEs showing whether the IQE is measurable or not . 10
Figure 4 – IQE measurement with TDEL . 10
Figure 5 – Sequence of IQE determination with TDEL . 12
Figure A.1 – Radiant power as a function of forward current at various temperatures
(category 1) . 13
Figure A.2 – Relative EQE as a function of forward current at various temperatures
(category 1) . 14
Figure A.3 – Check T in relative EQE curves (category 1) . 14
c
Figure A.4 – Evaluation of the relative EQE (category 1) . 15
Figure A.5 – IQE as a function of forward current at various temperatures including an
operating temperature (category 1) . 15
Figure A.6 – Radiant power as a function of forward current at various temperatures
(category 2) . 16
Figure A.7 – Relative EQE as a function of forward current at various temperatures
(category 2) . 17
Figure A.8 – Check T in relative EQE curves (category 2) . 17
c
Table A.1 – Summary of test report . 18

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SEMICONDUCTOR DEVICES –
Part 5-9: Optoelectronic devices – Light emitting diodes –
Test method of the internal quantum efficiency based
on the temperature-dependent electroluminescence

FOREWORD
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International Standard IEC 60747-5-9 has been prepared by subcommittee 47E: Discrete
semiconductor devices, of IEC technical committee 47: Semiconductor devices.
The text of this International Standard is based on the following documents:
CDV Report on voting
47E/651/CDV 47E/676/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

– 4 – IEC 60747-5-9:2019 © IEC:2019
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SEMICONDUCTOR DEVICES –
Part 5-9: Optoelectronic devices – Light emitting diodes –
Test method of the internal quantum efficiency based
on the temperature-dependent electroluminescence

1 Scope
This part of IEC 60747 specifies the measuring method of the internal quantum efficiency
(IQE) of single light emitting diode (LED) chips or packages without phosphor. White LEDs for
lighting applications are out of the scope of this document. This document utilizes the relative
external quantum efficiencies (EQEs) measured at cryogenic temperatures and at an
operating temperature, which is called temperature-dependent electroluminescence (TDEL).
In order to identify the reference IQE of 100 %, the maximum values of the peak EQE are
found by varying the environmental temperature and current.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60747-5-6:2016, Semiconductor devices – Part 5-6: Optoelectronic devices – Light
emitting diodes
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
radiant power
Φ
e
power emitted, transmitted or received in the form of radiation
Note 1 to entry: The unit used is: W. Radiant power is also known as the "radiant flux".
[SOURCE: IEC 60747-5-8:2019, 3.1.1]
3.1.2
internal quantum efficiency
η
IQE
ratio of the number of photons emitted from the active region per unit time to the number of
electrons injected into the LED per unit time

– 6 – IEC 60747-5-9:2019 © IEC:2019
Φ hν
e,active
η =
IQE
Iq
F
where
Φ is the radiant power emitted from the active region
e,active
hν is the mean photon energy
I is the forward current
F
q is the elementary charge
Note 1 to entry: It is in general a function of ambient temperature (T ) and forward current (I ).
a F
[SOURCE: IEC 60747-5-8:2019, 3.2.4, modified – The note has been added.]
3.1.3
external quantum efficiency
η
EQE
ratio of the number of photons emitted into the free space per unit time to the number of
electrons injected into the LED per unit time
Φ hν
e
η =
EQE
Iq
F
where
Φ is the radiant power
e
Note 1 to entry: It is in general a function of ambient temperature (T ) and forward current (I ).
a F
[SOURCE: IEC 60747-5-8:2019, 3.2.3, modified – The note has been added.]
3.1.4
injection efficiency
η
IE
ratio of the number of electrons injected into the active region per unit time to the number of
electrons injected into the LED per unit time
I
F,active
η =
IE
I
F
where
I is the portion of the forward current injected into the active region
F,active
[SOURCE: IEC 60747-5-8:2019, 3.2.6]
3.1.5
radiative efficiency
η
RE
ratio of the number of photons emitted from the active region per unit time to the number of
electrons injected into the active region per unit t
...