EN 60904-8:2014

SLOVENSKI STANDARD
01-november-2014
1DGRPHãþD
SIST EN 60904-8:2001
Fotonapetostne naprave - 8. del: Merjenje spektralnega odziva fotonapetostne (PV)
naprave (IEC 60904-8:2014)
Photovoltaic devices - Part 8: Measurement of spectral response of a photovoltaic (PV)
device
Dispositifs photovoltaïques - Partie 8: Mesure de la réponse spectrale d'un dispositif
photovoltaïque (PV)
Ta slovenski standard je istoveten z: EN 60904-8:2014
ICS:
27.160 6RQþQDHQHUJLMD Solar energy engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 60904-8
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2014
ICS 27.160 Supersedes EN 60904-8:1998
English Version
Photovoltaic devices - Part 8: Measurement of spectral
responsivity of a photovoltaic (PV) device
(IEC 60904-8:2014)
Dispositifs photovoltaïques - Partie 8: Mesure de la Photovoltaische Einrichtungen - Teil 8: Messung der
sensibilité spectrale d'un dispositif photovoltaïque (PV) spektralen Empfindlichkeit einer photovoltaischen
(CEI 60904-8:2014) (PV-)Einrichtung
(IEC 60904-8:2014)
This European Standard was approved by CENELEC on 2014-06-12. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 60904-8:2014 E
Foreword
The text of document 82/822/FDIS, future edition 3 of IEC 60904-8, prepared by IEC/TC 82 "Solar
photovoltaic energy systems" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN 60904-8:2014.
The following dates are fixed:
(dop) 2015-03-12
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2017-06-12
standards conflicting with the
document have to be withdrawn
This document supersedes EN 60904-8:1998.

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 60904-8:2014 was approved by CENELEC as a European
Standard without any modification.

- 3 - EN 60904-8:2014
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.

NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu
Publication Year Title EN/HD Year

IEC 60904-3 -  Photovoltaic devices - EN 60904-3 -
Part 3: Measurement principles for
terrestrial photovoltaic (PV) solar devices
with reference spectral irradiance data
IEC 60904-7 -  Photovoltaic devices - EN 60904-7 -
Part 7: Computation of the spectral
mismatch correction for measurements of
photovoltaic devices
IEC 60904-9 -  Photovoltaic devices - EN 60904-9 -
Part 9: Solar simulator performance
requirements
IEC 61215 -  Crystalline silicon terrestrial photovoltaic EN 61215 -
(PV) modules - Design qualification and
type approval
IEC 61646 -  Thin-film terrestrial photovoltaic (PV) EN 61646 -
modules - Design qualification and type
approval
IEC/TS 61836 -  Solar photovoltaic energy systems - CLC/TS 61836 -
Terms, definitions and symbols
ISO/IEC 17025 -  General requirements for the competence EN ISO/IEC 17025 -
of testing and calibration laboratories

IEC 60904-8 ®
Edition 3.0 2014-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Photovoltaic devices –
Part 8: Measurement of spectral responsivity of a photovoltaic (PV) device

Dispositifs photovoltaïques –
Partie 8: Mesure de la sensibilité spectrale d'un dispositif photovoltaïque (PV)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX S
ICS 27.160 ISBN 978-2-8322-1530-2

– 2 – IEC 60904-8:2014 © IEC 2014
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Marking . 6
4 Testing . 7
4.1 General . 7
4.2 Special considerations . 7
4.3 Measurement under white bias light . 7
4.4 Applying a bias voltage to the device under test . 7
5 General description of spectral responsivity measurement . 7
6 Apparatus . 9
6.1 General . 9
6.2 Monochromatic light source . 11
6.3 PV device holder and temperature control . 12
6.4 PV device contacts . 12
6.5 Bias light . 12
6.6 DC measurements . 12
6.7 AC measurements in the presence of bias light . 13
6.8 Reference device . 13
7 Measurement of spectral responsivity using a constant light source . 13
7.1 General method with a grating monochromator or filter wheel . 13
7.2 Measurement of the reference device for setup calibration . 13
7.3 Measurement of the device under test . 14
7.4 Calculation of spectral responsivity . 15
7.5 Simplifications . 16
8 Measurement of spectral responsivity under pulsed light . 16
8.1 Additional apparatus . 16
8.2 Test procedure . 17
9 Measurements of series-connected modules . 17
9.1 General . 17
9.2 Additional apparatus . 17
9.3 Test procedure . 17
9.4 Calculation of spectral responsivity . 20
10 Report . 20

Figure 1 – Example block diagram of a differential spectral responsivity measuring
instrument using a continuous light source and a grating monochromator . 10
Figure 2 – Example block diagram of a differential spectral responsivity measuring
instrument using a continuous light source and bandpass filters . 11
Figure 3 – Example block diagram of a spectral responsivity measuring instrument
using a pulsed light source and bandpass filters . 17
Figure 4 – Example of the measurement setup for the differential spectral responsivity
measurement of a target cell in a PV module, where the supplemental bias light is
applied on all the cells in the module other than the target cell . 18

IEC 60904-8:2014 © IEC 2014 – 3 –
Figure 5 – Example of the measurement setup for the differential spectral responsivity
measurement of a target cell in a PV module, where the supplemental bias light is
applied on all the cells in a string of the module other than the target cell . 19
Figure 6 – Determination of the bias voltage V to set the voltage across the target
b
cell to the short-circuit condition (see 9.3) . 19

– 4 – IEC 60904-8:2014 © IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PHOTOVOLTAIC DEVICES –
Part 8: Measurement of spectral responsivity
of a photovoltaic (PV) device
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) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60904-8 has been prepared by IEC technical committee 82: Solar
photovoltaic energy systems.
This third edition cancels and replaces the second edition published in 1998 and constitutes a
technical revision.
The main technical changes with respect to the previous edition are listed below:
• Re-writing of the clause on testing
• Addition of a new clause for the measurement of series-connected modules
• Addition of the requirements of ISO/IEC 17025
• Additional figures
IEC 60904-8:2014 © IEC 2014 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
82/822/FDIS 82/843/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
A list of all parts in the IEC 60904 series, published under the general title Photovoltaic
devices, can be found on the IEC website.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 60904-8:2014 © IEC 2014
PHOTOVOLTAIC DEVICES –
Part 8: Measurement of spectral responsivity
of a photovoltaic (PV) device
1 Scope
This International Standard specifies the requirements for the measurement of the spectral
responsivity of both linear and non-linear photovoltaic devices. It is only applicable to single-
junction devices. The spectral responsivity of a photovoltaic device is used in cell
development and cell analysis, as it provides a measure of recombination and other
processes occurring inside the semiconductor or cell material system.
The spectral responsivity of a photovoltaic device is used for the correction of the spectral
mismatch if a PV device is calibrated in a setup where the measurement spectrum is different
from the reference spectral irradiance data given in IEC 60904-3 and a reference device with
a different spectral responsivity to the device under test is used. This procedure is given in
IEC 60904-7.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60904-3, Photovoltaic devices – Part 3: Measurement principles for terrestrial
photovoltaic (PV) solar devices with reference spectral irradiance data
IEC 60904-7, Photovoltaic devices – Part 7: Computation of the spectral mismatch correction
for measurements of photovoltaic devices
IEC 60904-9, Photovoltaic devices – Part 9: Solar simulator performance requirements
IEC 61215, Crystalline silicon terrestrial photovoltaic (PV) modules – Design qualification and
type approval
IEC 61646, Thin-film terrestrial photovoltaic (PV) modules – Design qualification and type
approval
IEC/TS 61836, Solar photovoltaic energy systems – Terms, definitions and symbols
ISO/IEC 17025, General requirements for the competence of testing and calibration
laboratories
3 Marking
Each photovoltaic device should carry a clear and indelible marking. This marking should be
cross-referenced against:
– name, monogram or symbol of the manufacturer;
– base material and type of photovoltaic device;

IEC 60904-8:2014 © IEC 2014 – 7 –
– type number or identification, if available;
– serial number, if applicable.
When the photovoltaic devices to be tested are prototypes of a new design and not from
production, this fact shall be noted in the test report (see Clause 10).
4 Testing
4.1 General
The photovoltaic device shall be subjected to one of the procedures for spectral responsivity
measurements defined in Clauses 7 to 9.
4.2 Special considerations
Preconditioning – Before beginning the measurements, the device under test shall be
stabilized (if necessary) by an appropriate light soaking test procedure, as specified in
IEC 61215 or IEC 61646. Different photovoltaic technologies may require different pre-
conditioning procedures.
4.3 Measurement under white bias light
The procedures in Clause 7 and 9 require a white bias light being applied to the device under
test during the determination of spectral responsivity. Under bias light conditions, not the
spectral responsivity but rather the differential spectral responsivity is measured. The spectral
responsivity can be determined from the differential spectral responsivity by taking the non-
linearity into account based on a series of differential spectral responsivity measurements at
bias light levels generating short-circuit currents in the device ranging from 5 % to 110 % of
that at standard test conditions (see Clause 5). Most crystalline silicon solar cells have a
differential spectral responsivity at a bias light generating 30 % to 40 % of their short-circuit
current at standard test conditions that is identical to the spectral responsivity at standard test
conditions. Therefore, the measurement should be performed with such bias light levels if the
non-linearity of a crystalline silicon PV device is not determined. If the non-linearity is
confirmed to be negligible, i.e. the differential spectral responsivity is constant within the
irradiance range of interest, the differential spectral responsivity at a specific bias light level
may be used. For details see Clause 5.
4.4 Applying a bias voltage to the device under test
Generally, the spectral responsivity of a photovoltaic device is measured at short-circuit
conditions (zero bias voltage) of the photovoltaic device and used for the purposes of cell
analysis and calculating the spectral mismatch.
In order to measure the spectral responsivity of the specimen under a specific voltage, a bias
voltage may need to be applied. The bias voltage of the device shall be controlled by an
external voltage source. If a bias voltage is applied it shall be specified in the report.
5 General description of spectral responsivity measurement
The spectral responsivity of a photovoltaic (PV) device is measured by irradiating it by means
of a narrow-bandwidth light source at a series of different wavelengths covering its
responsivity range, and measuring the short-circuit current and monochromatic irradiance at
each of these wavelengths (formula 1), or short-circuit current and monochromatic light beam
power (formula 2). The first type of measurement results in the spectral irradiance
–2
responsivity with the unit A/W∙m . In order to determine the spectral responsivity as defined
in IEC/TS 61836 this needs to be divided by the area of the device under test whereas the
second type results directly in the spectral responsivity in the unit A/W.

– 8 – IEC 60904-8:2014 © IEC 2014
In order to determine the output current of the device, the bias light as well as the
monochromatic light should irradiate the entire area of the device uniformly. It is important to
illuminate effectively the entire area of the device, as light not directly falling onto the active
area may also contribute to the measured signal. If the spectral responsivity is used for the
calculation of the spectral mismatch correction according to IEC 60904-7 the illuminated area
during the measurement of the spectral responsivity should be identical to that during the
measurement of the current-voltage characteristics. This is normally the entire device area. If
not it should be suitably delimitated by an aperture.
In case the area of the device is larger than the respective beam sizes the latter should be
scanned appropriately across the entire device area to provide a uniform illumination. If both
beams are scanned, the scanning should be synchronous with the bias light always
illuminating a spot larger than the monochromatic light.
The temperature of the device should be controlled.
The current density of the device under test at each wavelength is divided by the respective
irradiances to give spectral responsivity.
s(λ) = I (λ)/E(λ)/A (1)
sc
where:
s(λ) is the spectral responsivity of the device under test at the wavelength λ;
I (λ) is the short-circuit current of the device under test at the wavelength λ;
sc
E(λ) is the irradiance of the light source at the wavelength λ;
A is the area of the device under test.
The area of the device under test shall be noted in the test report.
Alternatively, the short-circuit current I (λ) and the radiant power incident on the device P(λ)
sc
may be measured. The spectral responsivity is then determined as:
s(λ) = I (λ)/P(λ) (2)
sc
where:
I (λ) is the short-circuit current of the device under test at the wavelength λ;
sc
P(λ) is the radiant power incident on the device at the wavelength λ.
The determination of P(λ) requires the measurement of the area of the device under test. This
area shall be noted in the test report.
In practice (see Clauses 7 and 9) a small modulated signal originating from the
monochromatic light is superimposed on a large bias signal originating from the white bias
light. In such cases the evaluated quantities need to be treated as differential and a
wavelength dependent differential spectral responsivity (DSR) 𝑠̃(𝜆,𝐸) is determined for a
specific bias light irradiance 𝐸. The spectral responsivity at standard test conditions 𝑠(𝜆)|
STC
will equal the differential spectral responsivity only if the device is strictly linear. If the non-
linearity is confirmed to be negligible, the differential spectral response at a specific bias light
level may be used. For example, if the differential spectral response or the resultant spectral
mismatch factor is constant within the bias light levels to generate the I between 5 % and
sc
110 % of standard test conditions, the differential spectral response at a bias level of 100 %
of standard test conditions may be used. In all other cases the DSR shall be measured at a
sufficient number of bias irradiances and the resultant spectral responsivity can be calculated
or a specific bias light irradiance 𝐸 shall be found with 𝑠̃(𝜆,𝐸 )≈𝑠(𝜆)| .
0 0 STC
IEC 60904-8:2014 © IEC 2014 – 9 –
6 Apparatus
6.1 General
A spectral responsivity measurement system consists of a continuous (chopped or unchopped)
or pulsed monochromatic light source, an optional beam splitting assembly with a monitor
detector, a device stage able to hold the device under test, a reference device, an optional
bias light assembly and electrical instrumentation. Figures 1(a, b) and 2(a, b) show examples
of test arrangements for the measurement of the DSR of a solar cell.
If an optical chopper is used (Figures 1 and 2) care needs to be taken that no bias light
reflected of the optical chopper reaches the test plane.

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