Concentrator Assemblies

R&D Services

Our R&D services comprise:

Integrating and Connecting Different Cell Concepts

Customized Assembly Designs

  • Substrate design (e.g. conductive path, substrate materials, submount, thermal management)
  • Electrical contacting (bonding, welding and soldering processes)

Reliability and Long-Term Stability Testing

Concentrator photovoltaics employs cheap optics to focus sunlight onto small solar cell surfaces, with different systems distinguished by their solar concentration factor. Our work primarily focuses on low and medium concentration (>1 - 50x) and high concentration (300 - 1000x) systems.

The solar cell assembly, comprising a substrate, solar cell and electrical contacts, is a key component in concentrator photovoltaic (CPV), power-by-light or thermophotovoltaic (TPV) systems. Different system designs utilize different solar cell assembly structures, and we produce such assemblies with active and passive cooling systems in various sizes.

High concentration systems employ III-V multi-junction solar cells, and the development of such systems at Fraunhofer ISE is based at the Concentrator Technology Evaluation Center (Con-TEC).

Modified silicon or thin-film solar cells are used in low concentration modules. We develop these in our PV Module Technology Evaluation Center (Module-TEC) and at Con-TEC, thus combining expertise in silicon flat-plate module technology and high concentration photovoltaics.

Research at Con-TEC and the Module-TEC primarily focuses on optimizing design, manufacturing processes and CPV module reliability. Our expertise in the field of thermal, optical and electrical simulation is shared with our clients, and we optimize and develop both manufacturing processes and innovative systems.

A variety of experimental methods are available for characterizing CPV components.

Selcted Research Projects



Development of a Highly Concentrating CPV Module Based on Modern Micro-Production Technology


CPV-T System

CPV-T system combined with desalination systems




Highly efficient concentrator module with GaSb-based four-junction solar cell



CPV Module in Modular Design; Subproject: Module Design and Module Performance


Current publications - Concentrator Assemblies:

YearTitle/AuthorDocument Type
2021Technical Boundaries of Micro-CPV Module Components: How Small is Enough: Presentation held at 17th International Conference on Concentrating Photovoltaic Systems (CPV), Online Conference, Germany, 12.-14. April 2021
Wiesenfarth, M.; Martínez, J.F.; Steiner, M.; Iankov, D.; Nitz, P.; Dimroth, F.; Helmers, H.
2021Technical Boundaries of Micro-CPV Module Components: How Small is Enough?: Paper presented at 17th International Conference on Concentrating Photovoltaic Systems, CPV 2021, Online, Germany, 12.-14.04.2021
Wiesenfarth, M.; Iankov, D.; Martínez, J.F.; Nitz, P.; Steiner, M.; Dimroth, F.; Helmers, H.
2020Development and Outdoor Characterization of a Hybrid Bifacial HCPV Module
Martinez, J.; Steiner, M.; Wiesenfarth, M.; Fellmeth, T.; Dörsam, T.; Wiese, M.; Glunz, S.W.; Dimroth, F.
Journal Article
2019FLATCON® CPV Module Technology: A New Design based on the Evaluation of 10 Years of Outdoor Measurement Data
Wiesenfarth, M.; Steiner, M.; Dörsam, T.; Siefer, G.; Dimroth, F.; Nitz, P.; Bett, A.W.
Conference Paper
2019Outdoor Experimental Characterization of Novel High-Efficiency High-Concentrator Photovoltaic (HCPV) modules Using Achromatic Doublet on Glass (ADG) Fresnel Lenses as Primary Optics
Vallerotto, G.; Wiesenfarth, M.; Victoria, M.; Steiner, M.; Anton, I.; Jost, N.; Askins, S.; Sala, G.
Conference Paper
2019Pushing Energy Yield with Concentrating Photovoltaics
Steiner, Marc; Wiesenfarth, Maike; Martínez Sánchez, Juan Francisco; Siefer, Gerald; Dimroth, Frank
Conference Paper
2019Terawatt-Scale Photovoltaics: Transform Global Energy
Bett, A.W.; Haegel, N.M.; Atwater, H.; Barnes, T.; Breyer, C.; Burrell, A.; Chiang, Y.-M.; Wolf, S. de; Dimmler, B.; Feldmann, D.; Glunz, S.; Goldschmidt, J.C.; Hochschild, D.; Inzunza, R.; Kaizuka, I.; Kroposki, B.; Kurtz, S.; Margolis, R.; Leu, S.; Matsubara, K.; Metz, A.; Metzger, W.K.; et al.
Journal Article
2019Validierung von Methoden für den Zuverlässigkeitsnachweis von Konzentratorsolarzellen
Eltermann, Fabian; Wilde, Jürgen (Referent); Glunz, Stefan W.; Bett, Andreas W. (Betreuer)
20184-terminal CPV module capable of converting global normal irradiance into electricity
Martínez, Juan F.; Steiner, Marc; Wiesenfarth, Maike; Dimroth, Frank
Conference Paper
2018Analysis of the performance of an on-axis mirror module design compared to a FLATCON module
Wiesenfarth, Maike; Gamisch, Sebastian; Jakob, Peter; Steiner, Marc; Bett, Andreas
Conference Paper
2018Challenges in the Design of Concentrator Photovoltaic (CPV) Modules to Achieve Highest Efficiencies
Wiesenfarth, M.; Anton, I.; Bett, A.W.
Journal Article
2018Component cell-based restriction of spectral conditions and the impact on CPV module power rating
Steiner, Marc; Muller, Matt; Siefer, Gerald; Bett, Andreas W.
Journal Article
2018Operation & maintenance - the key for reliable performance in a CPV power plant
Wüllner, Johannes; Steiner, Marc; Wiesenfarth, Maike; Bett, Andreas
Conference Paper
2018Systematic design evaluation on the example of a concentrator photovoltaic module with mirror optics and passive heat dissipation
Wiesenfarth, Maike; Gamisch, Sebastian; Jakob, Peter; Steiner, Marc; Bett, Andreas
Journal Article
2018Trends in Solar Electricity: Presentation held at EuroSun, 12th International Conference on Solar Energy for Buildings and Industry 2018, Rapperswil, Switzerland, September 11th, 2018
Bett, A.W.
2017An end of service life assessment of PMMA lenses from veteran concentrator photovoltaic systems
Miller, D.C.; Khonkar, H.I.; Herrero, R.; Anton, I.; Johnson, D.K.; Hornung, T.; Schmid-Schirling, T.; Vinzant, T.B.; Deutch, S.; To, B.; Sala, G.; Kurtz, S.R.
Journal Article
2017Performance and failure analysis of concentrator solar cells after intensive stressing with thermal, electrical, and combined load
Eltermann, F.; Ziegler, L.; Wiesenfarth, M.; Wilde, J.; Bett, A.W.
Conference Paper
2017Progress in R&D on CPV cells and modules for highest efficiencies within the EU-funded project CPVMatch: Presentation held at CPV 2017, 13th International Conference on Concentrator Photovoltaic Systems, Ottawa, Canada, May 01 - 03, 2017
Philipps, S.; Baudrit, M.; Grange, F.; Hillerich, K.; Parmesani, R.; Román, E.
2017Research on multi-junction solar cells at Fraunhofer ISE: Presentation held at CPV 2017, 13th International Conference on Concentrator Photovoltaic Systems, Ottawa, Canada, May 01 - 03, 2017
Bett, A.W.; Beutel, P.; Cariou, R.; Feifel, M.; Heckelmann, S.; Hoehn, O.; Klinger, V.; Lackner, D.; Niemeyer, M.; Ohlmann, J.; Oliva, E.; Predan, F.; Siefer, G.; Dimroth, F.
2017The role of draft facets in temperature effects in silicone-on-glass Fresnel lens applications
Jakob, P.; Nitz, P.
Conference Paper
2016CPV-T Mirror Dish System Combined with Water Desalination Systems
Wiesenfarth, M.; Went, J.; Bösch, A.; Dilger, A.; Kec, T.; Kroll, A.; Koschikowsi, J.; Bett, A.W.
Conference Paper
2016High Efficiency GaInP/GaAs Tandem Wafer Bonded Solar Cell on Silicon: Presentation held at 3rd EU PV General Assembly 2016, University of Barcelona - Faculty of Physics Av. Diagonal, 647, Spain, 25.05.2016-26.05.2016
Cariou, R.; Benick, J.; Dimroth, F.
2016Improved in situ performance testing of line-concentrating solar collectors: Comprehensive uncertainty analysis for the selection of measurement instrumentation
Zirkel-Hofer, A.; Perry, S.; Fahr, S.; Kramer, K.; Heimsath, A.; Scholl, S.; Platzer, W.
Journal Article
2016Recent Development in Direct Generation of Hydrogen Using Multi-Junction Solar Cells
Ohlmann, J.; Martínez, Juan F.; Lackner, D.; Förster, P.; Steiner, M.; Fallisch, A.; Dimroth, F.
Conference Paper
2015CPV module with fresnel lens primary optics and homogenizing secondary optics
Wiesenfarth, M.; Dörsam, T.; Eltermann, F.; Hornung, T.; Siefer, G.; Steiner, M.; Riesen, S. van; Neubauer, M.; Boos, A.; Wanka, S.; Gombert, A.; Bett, A.W.
Conference Paper
2015NGCPV: A new generation of concentrator photovoltaic cells, modules and systems (a final review)
Datas, A.; Cristóbal, A.B.; Sala, G.; Anton Hernandez, I.; Minano, J.C.; Benítez, P.; Algora, C.; Bett, A.W.; Lackner, D.; Niemeyer, M.; Philipps, S.P.; Siefer, G.; Ekins-Daukes, N.J.; Roca, F.; Cancro, C.; Luque-Heredia, L.; Warmuth, W.; Baudrit, M.; Okada, Y.; Sugiyama, M.; Hishikawa, Y.; Takamoto, T.; Araki, K.; Fukuyama, A.; Nishioka, K.; Suzuki, H.; Kuze, N.; Moriyasu, Y.; Kita, T.; Kotagiri, A.; Kojima, N.; Martí Vega, A.; Yamaguchi, M.; Luque, A.
Conference Paper
2015Photoluminescence-based current-voltage characterisation of individual subcells in multi-junction devices
Alsonso-Álvarez, D.; Lackner, D.; Philipps, S.P.; Bett, A.W.; Ekins-Daukes, N.J.
Conference Paper
2015Solarenergie zur Stromerzeugung
Kiefer, K.
Book Article
2014High-Efficiency - A Key for CPV: Presentation held at CPV-10, 10th International Conference on Concentrator Photovoltaic Systems 2014, Albuquerque, USA, 08.04.2014
Bett, A.W.
2014III-V multi-junction solar cells
Philipps, S.P.; Bett, A.W.
Book Article
2014A Low Concentration Receiver Concept for Cost Effective Crystalline Back Contact Cells
Ebert, M.; Dörsam, T.; Fellmeth, T.; Hädrich, I.; Eitner, U.; Biro, D.; Wiesenfarth, M.; Noriega, P.; Caparros, S.; Castano, F.
Conference Paper
2014Modeling of concentrating photovoltaic and thermal systems
Helmers, H.; Bett, A.W.; Parisi, J.; Agert, C.
Journal Article
2014SOPHIA CPV module round robin: Power rating at CSOC
Steiner, M.; Siefer, G.; Baudrit, M.; Dominguez, C.; Anton, I.; Roca, F.; Fucci, R.; Pugliatti, P.M.; Stefano, A. di; Kenny, R.; Morabito, P.; Muller, M.
Conference Paper
2014SOPHIA CPV Module Round Robin: Power Rating at CSOC
Siefer, G.; Steiner, M.; Baudrit, M.; Dominguez, C.; Antón, , I.; Roca, F.; Fucci, F.; Pugliatti, P.; Stefano, A. di; Kenny, R.; Morabito, P.
Conference Paper
2014Strategic Vision on PV Research Infrastructure in Europe
Kroon, J.; Bruijne, M. de; Bennett, I.; Arrowsmith, G.; Malbranche, P.; Merten, J.; Assoa, Y.B.; Taylor, N.; Georgyvan, S.; Lauermann, I.; Hüpkes, J.; Siefer, G.; Köhl, M.; Warta, W.; Roca, F.; Theologitis, I.
Conference Paper
2013Advanced liquid cooling in HCPVT systems to achieve higher energy efficiencies
Zimmermann, S.; Helmers, H.; Tiwari, M.K.; Escher, W.; Paredes, S.; Neves, P.; Poulikakos, D.; Wiesenfarth, M.; Bett, A.W.; Michel, B.
Conference Paper
2013Analysis of high concentration passively cooled CPV module designs using mirror optics
Dreger, M.; Wiesenfarth, M.; Schmid, T.; Bett, A.W.
Conference Paper
2013Modeling the thermal runaway effect in CPV modules
Steiner, M.; Siefer, G.; Bett, A.W.
Conference Paper
2013Temperature dependent electroluminescence and voltages of multi-junction solar cells
Karcher, C.; Helmers, H.; Schachtner, M.; Dimroth, F.; Bett, A.W.
Conference Paper
This publication list has been generated from the publication database Fraunhofer-Publica.