Class AAA LED-based solar simulator
for steady-state measurements and light soaking
M.
1
Stuckelberger ,
B.
1
Perruche ,
M.
2
Bonnet-Eymard ,
Y.
1
Riesen ,
M.
2
Despeisse ,
F.-J.
1
Haug ,
C.
1
Ballif
1Ecole
Polytechnique Fédérale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and Thin Film Electronics Laboratory,
Rue de la Maladière, 2000 Neuchâtel, Switzerland, 2CSEM SA, CSEM PV-Center, Rue Jaquet-Droz 1, 2002 Neuchâtel, Switzerland
Email: michael.stuckelberger@epfl.ch
Motivation
Design
1) LEDs mounted on a cooling block
2) Temperature-controlled substrate holder
3) Mirrors around the LED cooling block
and light path
4) Power supplies for the LEDs
5) Electronics for LED control
6) Chiller for the LED cooling circuit
7) Chiller for temperature control
of the substrate holder
8) Computer to control the solar simulator
9-11) Setup for I(V) kinetics measurements
(30 x 4 channels)
Light-induced changes are observed for many PV technologies
like CIGS or organic solar cells.
Here, we study the Staebler-Wronski effect of a-Si:H solar cells.
No solar simulator existed so far providing:
• Full spectral flexibility
• Temperature control
• Intensity up to 5 sun equivalents
• Multichannel kinetics measurements
Such a simulator would allow:
• Light-soaking under variable conditions
• Automated variable-illumination measurements (VIM)
• Automated temperature-coefficient measurements
Electronics
Low-cost power supply to power
5 V and 12 V LED channels
via in-house designed electronic circuits
High light intensity
Maximum 5 sun
equivalent
16 Modules
12 LED channels
per module
Up to 4 sun
equivalent AM1.5g
btw. 400 and 750 nm
Better than class AAA
Application
LED-modules parallel and of same size as
sample holder ⇒ good intrinsic homogeneity
Individual power regulation ⇒ homogeneity
adjustable to any precision required
Study of light-induced-degradation kinetics
(3 cells for each type)
Conclusions
11 types of LEDs for full spectral flexibility
between 400 and 750 nm.
For enhanced spectral range:
LEDs in UV or IR can be added.
LEDs provide high intrinsic stability and long life time
Work published in Stuckelberger, et al., IEEE J-PV 4 (5), 2014
Work supported by:
• The Swiss Federal Office of Energy (Grant SI/500750-01)
• The Competence Center Energy and Mobility, and Swisselectric Research
(DURSOL project, www.dursol.ch)
• The FP7 Project Fast Track (www.fast-track.eu)
funded by the European Commission (Grant 283501)
Class AAA solar simulator demonstrated,
fully based on LEDs:
• Spectral flexibility from 400 to 750 nm
(11 types of LEDs)
• High intrinsic temporal stability
• Uniformity adjustable (each LED module
controlled individually)
• Low-cost thanks to compact printed electronic
circuit and standard power supply
• Modular design for easy up- and downscalability
• Up to 5 sun light intensity without concentrator
optics
Results obtained with this solar simulator published in:
• Stuckelberger, et al., JAP 116, 2014
• Moulin, et al., IEEE J-PV 4 (5), 2014
• Stuckelberger, et al., accepted for PIP, 2014
• Stuckelberger, et al., pres. A1.02, MRS spring, 2014
• Stuckelberger, et al., pres. 3CO.6.6, EU-PVSEC, 2014
• Stuckelberger, PhD thesis, 2014