Solar module for building integration

The concept of the mosaic module allows an aesthetic and individual design of photovoltaic building façades.

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The Module Technology Center provides industrial equipment for module prototyping and analytic platforms for device characterization.

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Industrial Module Manufacturing

The IR-stringer allows high-throughput interconnection of 3, 4 and 5 busbar solar cells in half- and full-size formats.

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Colored Modules for Building Integration

The special layer set-up provides a very high color saturation and a very good angular color stability. Compared to an uncoated cover glass, the loss of generated solar power is only 7%.

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Shingle Module

High-efficiency module concept using shingled cell interconnection.

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Module Technology

R&D Services

Cell Interconnection

The interconnection of solar cells causes ohmic and optical losses in a module. We use various soldering technologies and industrial stringing equipment for measuring and optimizing the quality of the joints.


With advanced characterization methods we are able to analyse all aspects of laminate properties. We focus on fast and accurate methods to accelerate product and process development cycles.

Integrated Modules

We develop integrated module designs to meet specific requirements and create tailored product solutions.

Module Efficiency

Solar cells usually suffer from losses when integrated into a module. We analyze the effects down to the material level and assess the potential for optimization.



Module Technology Center with industrial production equipment and analytic characterization tools.

Software Solution



Software for analysis of the cell-to-module ratio and for optimization of module efficiency and power by Fraunhofer ISE.

Fraunhofer ISE offers a comprehensive range of services for module product development and materials testing. We provide support for turning innovative ideas into reliable, efficient and competitive products, as well as for improving quality and efficiency in existing module and interconnection concepts.

Our research covers the integration of high-efficiency solar cells, reliable soldering processes, conductive adhesive technology, laminate-free edge-sealed solar modules and the cell-to-module (CTM) power and efficiency optimization.

We are able to develop, improve and test your products to meet industrial demands. Our excellently equipped Fraunhofer ISE Module Technology Center (Module-TEC) supports development from first ideas to module pilot manufacturing.

On this topic from our research blog »Innovation4E«:

Software Reduces Losses in Solar PV Modules

Blog post by Max Mittag

Max MittagA photovoltaic module consists of many interconnected solar cells. One cannot say, however, that the module power is simply the sum of the individual cells. Power losses due to reflection, absorption or electrical losses come about in the integration process. These cell-to-module, or CTM, losses have a large effect on the subsequent module performance and can vary greatly depending on the type of solar cell, material or module design. We at Fraunhofer ISE have created a model based on different material parameters in order to calculate these variations. With SmartCalc.CTM, we have developed a software program that makes PV modules (even) more efficient.


Latest Press Releases


Press Release - January 9, 2019

Adhesive Process Developed for Shingle Cell Technology

The Fraunhofer Institute for Solar Energy Systems ISE in Freiburg has developed a special adhesive process to interconnect silicon solar cells for the industrial production of shingle modules. The market demand for shingle modules is rising rapidly due to their high efficiency and pleasing aesthetics. The cell stringer at Fraunhofer ISE is unique in Germany. It offers a wide range of possibilities for the prototype production of this highly efficient module.


Press Release - October 24, 2019

Joint Research by Fraunhofer ISE and Heraeus for High-performance Solar Modules

The Fraunhofer ISE and Heraeus are researching and optimizing novel, selectively coated cell connectors in a joint research project. The Selectively Coated Ribbon (SCRTM) cell connector achieves an average gain of 1.9 W in conventional 60-cell solar modules.


News - 25.04.2018

Fraunhofer ISE and teamtechnik Demonstrate Industrial Maturity of Electrically Conductive Adhesives

The Fraunhofer ISE and teamtechnik, an international leader in production technology, report that it is now possible to connect high efficiency solar cells using electrically conductive adhesives in series production.

Selected Research Projects


CTM 100+

Improving Module Performance by Analysis of Cell-to-Module Losses with SmartCalc.CTM



Efficient and Reliable Wire Connection of Solar Cells


Construct PV

Mosaic Modules as Photovoltaic Design Elements for Solar Facades

Brochure and Flyer: Module Technology

Brochure: Photovoltaic Module Technology

Flyer: SmartCalc.CTM: Precise Cell-to-Module Analysis

Flyer: Colored PV Modules for Building Integration

Flyer: Electrically Conducive Adhesives in PV Modules

Flyer: Increased Efficiency with Bifacial Shingle Modules

Flyer: Device-Integrated Photovoltaics

Flyer: Individual Designs for BIPV Modules

Current publications - Module Technology


YearTitle/AuthorDocument Type
2018Analysis of Grain-Size Distribution and Yield Strength of Interconnector Ribbons and Wires at Different Streching Conditions Using Color Etching
Walter, J.; Stegmaier, J.; Kraft, A.; Eitner, U.
Conference Paper
2018Approach for a Holistic Optimization from Wafer to PV System
Mittag, M.; Reise, C.; Wöhrle, N.; Eberle, R.; Schubert, M.; Heinrich, M.
Conference Paper
2018Comparison of Layouts for Shingled Bifacial PV Modules in Terms of Power Output, Cell-to-Module Ratio and Bifaciality
Mondon, A.; Klasen, N.; Fokuhl, E.; Mittag, M.; Heinrich, M.; Wirth, H.
Conference Paper
2018Decorated Building-Integrated Photovoltaic Modules: Power Loss, Color Appearance and Cost Analysis
Kutter, C.; Bläsi, B.; Wilson, H.R.; Kroyer, T.; Mittag, M.; Höhn, O.; Heinrich, M.
Conference Paper
2018Electrically conductive adhesives for photovoltaic modules
Geipel, Torsten; Rissing, Lutz (Referent); Maier, Hans Jürgen (Referent)
2018Light Attenuation Model to Predict Nominal Power of Modules with Light-Scattering Ceramic Printed Front Glasses
Kutter, C.; Wilson, H.R.; Pfreundt, A.; Heinrich, M.; Wirth, H.
Conference Paper
2018Mechanical and electrical properties of wave-shaped wires for low-stress interconnection of solar cells
Rendler, L.; Walter, J.; Goldenberg, S.; Beinert, A.J.; Wiese, S.; Eitner, U.
Journal Article
2018Mosaic Module Concept for Cost-Efficient and Aesthetic BIPV Modules
Mittag, M.; Ebert, M.; Wilson, H.R.; Fellmeth, T.
Conference Paper
2018A Multidimensional Optimization Approach to Improve Module Efficiency, Power and Costs
Shahid, J.; Mittag, M.; Heinrich, M.
Conference Paper
2018Optimization of electrically conductive adhesive bonds in photovoltaic modules
Geipel, T.; Meinert, M.; Kraft, A.; Eitner, U.
Journal Article
2018Rapid Calculation of the Backsheet Coupling Gain Using Ray Groups
Pfreundt, A.; Mittag, M.; Heinrich, M.; Eitner, U.
Conference Paper
2018Solder joint analysis on coated aluminum for silicon solar cell interconnection
De Rose, A.; Kraft, A.; Eitner, U.; Nowottnick, M.
Conference Paper
2017Abgedeckter PVT-Kollektor mit Low-e-Beschichtung und Belüftung als Überhitzungsschutz
Lämmle, M.; Panzer, C.; Hermann, M.
Conference Paper
2017Analysis of backsheet and rear cover reflection gains for bifacial solar cells
Mittag, M.; Grünzweig, A.; Wiese, M.; Mahmoud, N.; Schmid, A.; Heinrich, M.
Conference Paper
2017Analysis of peel and shear forces after temperature cycle tests for electrical conductive adhesives
Hoffmann, S.; Geipel, T.; Meinert, M.; Kraft, A.
Conference Paper
2017Cell-to-Module (CTM) analysis for photovoltaic modules with shingled solar cells: Paper presented at 44th IEEE Photovoltaic Specialists Conference 2017, Washington, DC, USA, 25.06.2017-30.06.2017
Mittag, M.; Zech, T.; Wiese, M.; Bläsi, D.; Ebert, M.; Wirth, H.
Conference Paper
2017Electrical and thermal modeling of junction boxes
Mittag, M.; Kutter, C.; Hoffmann, S.; Romer, P.; Beinert, A.J.; Zech, T.
Conference Paper
2017FEM-based development of novel back-contact PV modules with ultra-thin solar cells
Beinert, Andreas; Leidl, Roman; Sommeling, Paul; Eitner, Ulrich; Aktaa, Jarir
Conference Paper
2017Intermetallic compounds in solar cell interconnections: Microstructure and growth kinetics
Geipel, T.; Moeller, M.; Walter, J.; Kraft, A.; Eitner, U.
Journal Article
2017Low-temperature soldering for the interconnection of silicon heterojunction solar cells
De Rose, A.; Erath, D.; Geipel, T.; Kraft, A.; Eitner, U.
Conference Paper
2017Power loss through decorative elements in the front glazing of BIPV modules
Mittag, M.; Kutter, C.; Ebert, M.; Wilson, H.R.; Eitner, U.
Conference Paper
2017Ribbon interconnection of 6" BC-BJ Solar Cells
Walter, Johann; Rendler, Li Carlos; Halm, Andreas; Mihailetchi, Valentin; Kraft, Achim; Eitner, Ulrich
Journal Article
2017Shingled cell interconnection: A new generation of bifacial PV-modules
Klasen, N.; Mondon, A.; Kraft, A.; Eitner, U.
Conference Paper
2017Solar potential on commercial trucks: Results of an irradiance measurement campaign on 6 trucks in Europe and USA
Eitner, U.; Ebert, M.; Zech, T.; Schmid, C.; Watts, A.; Heinrich, M.
Conference Paper
2017Solder interconnection of aluminum foil rear side metallization for passivated emitter and rear solar cells
De Rose, A.; Kraft, A.; Gledhill, S.; Ali, M.T.; Kroyer, T.; Pscherer, C.; Graf, M.; Nekarda, J.; Eitner, U.
Conference Paper
2017Solder joint stability study of wire-based interconnection compared to ribbon interconnection
Walter, J.; Rendler, L.C.; Ebert, C.; Kraft, A.; Eitner, U.
Journal Article
2017Systematic PV-module optimization with the cell-to-module (CTM) analysis software "SmartCalc.CTM"
Mittag, M.; Ebert, M.
Journal Article
2017Thermomechanical stress analysis of PV module production processes by Raman spectroscopy and FEM simulation
Beinert, A.J.; Romer, P.; Büchler, A.; Haueisen, V.; Aktaa, J.; Eitner, U.
Journal Article
2017TPedge: Progress on cost-efficient and durable edge-sealed PV modules
Mittag, M.; Eitner, U.; Neff, T.
Conference Paper
2017Ultra-soft wires for direct soldering on finger grids of solar cells
Rendler, L.C.; Walter, J.; Kraft, A.; Ebert, C.; Wiese, S.; Eitner, U.
Journal Article
2016A comprehensive study of intermetallic compounds in solar cell interconnections and their growth kinetics
Geipel, T.; Moeller, M.; Kraft, A.; Eitner, U.
Journal Article
2016Comprehensive Study of Intermetallic Compounds in Solar Cell Interconnections Including Lead-Free, Low Melting Point Solders
Geipel, T.; Möller, M.; Kraft, A.; Eitner, U.
Conference Paper
2016The impact of ribbon properties on measured peel forces
Eitner, U.; Rendler, L.C.
Journal Article
2016Influence of Photovoltaic Module Mounting Systems on the Thermo-Mechanical Stresses in Solar Cells by FEM Modelling
Beinert, A.J.; Ebert, M.; Eitner, U.; Aktaa, J.
Conference Paper
2016Investigation of Thermomechanical Stress in Solar Cells with Multi Busbar Interconnection by Finite Element Modeling
Rendler, L.C.; Kraft, A.; Ebert, C.; Wiese, S.; Eitner, U.
Conference Paper
2016Low-temperature interconnection of PVD-aluminium metallization
Geipel, T.; Kumm, J.; Moeller, M.; Kroely, L.; Kraft, A.; Eitner, U.; Wolf, A.; Zhang, Z.; Wolfahrt, P.
Journal Article
2016Mechanical stress in solar cells with multi busbar interconnection - parameter study by FEM simulation
Rendler, L.C.; Kraft, A.; Ebert, C.; Eitner, U.; Wiese, S.
Conference Paper
2016Mosaic modules for improved design options in building integrated photovoltaic modules
Ebert, M.; Mittag, M.; Fellmeth, T.; Spribille, A.; Mindehoud, T.; Gijzen, G.; Fath, K.; Hecker, R.; Eitner, U.
Conference Paper
2016Die parasitäre Kapazität eines PV-Moduls als Ursache für einen erhöhten Ableitstrom und Indikator für den Feuchteeintrag im Verkapselungsmaterial
Berg, H.; Hsian Saw, M.; Philipp, D.
Conference Paper
2016Photovoltaic Modules: Technology and Reliability
Wirth, H.; Weiß, K.-A.; Wiesmeier, C.
2016A PVT collector concept with variable film insulation and low-emissivity coating
Lämmle, M.; Thoma, C.; Hermann, M.
Journal Article
2016TPEDGE: Glass-glass photovoltaic module for BIPV-applications
Mittag, M.; Neff, T.; Hoffmann, S.; Ebert, M.; Eitner, U.; Wirth, H.
Conference Paper
This publication list has been generated from the publication database Fraunhofer-Publica.