Photovoltaics

  • 26.1 % Record Efficiency for p-Type Crystalline Si Solar Cells

    Monocrystalline silicon solar cell with POLO-contacts for both polarities on the solar cell rear side. In the foreground the rear side of seven solar cells processed on one wafer can be seen. ISFH

    The Institute for Solar Energy Research Hameln (ISFH) and Leibniz Universität Hannover have developed a crystalline silicon solar cell with an independently confirmed efficiency of (26.10 +/- 0.31 %) under one sun. This is a world record for p-type Si material, which currently covers ~90% of the world photovoltaic market. The record cell uses a passivating electron-selective n+ type polysilicon on oxide (POLO) junction and a hole-selective p+ type POLO junction. It is the high selectivity of theses junctions that allow these high efficiencies. As an important step towards industrialization, laser ablation is used for the contact opening process.

  • 30.2 Percent Efficiency – New Record for Silicon-based Multi-junction Solar Cell

    Wafer-bonded III-V / Si multi-junction solar cell with 30.2 percent efficiency. ©Fraunhofer ISE/A. Wekkeli

    Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with the Austrian company EV Group (EVG) have successfully manufactured a silicon-based multi-junction solar cell with two contacts and an efficiency exceeding the theoretical limit of silicon solar cells. For this achievement, the researchers used a “direct wafer bonding” process to transfer a few micrometers of III-V semiconductor material to silicon, a well-known process in the microelectronics industry. After plasma activation, the subcell surfaces are bonded together in vacuum by applying pressure. The atoms on the surface of the III-V subcell form bonds with the silicon atoms, creating a monolithic device.

  • CalLab PV Modules Increases Measurement Precision to a Record 1.3 Percent

    Test stand developed at Fraunhofer ISE for measuring bifacial PV modules. Fraunhofer ISE

    The calibration laboratory at the Fraunhofer Institute for Solar Energy Systems ISE has achieved a best value: Photovoltaic modules can now be calibrated with an even higher measurement precision of 1.3 percent. Repeatability lies at 0.4 percent. Measurement precision is a decisive factor for quality assurance in the module production and for investments in PV plants. For a volume of 10 MW, for example, each percentage point increase in measurement precision corresponds to a monetary value of about 60,000 euros. “Maximum measurement precision is not just an academic exercise, rather it greatly helps gain the confidence of investors,” says Dr. Harry Wirth, division director of Photovoltaic Modules, Systems and Reliability. Module manufacturers have to maintain their quality assurance at a high level daily and guarantee their sold output. Power plant operators must know the module power as exact as possible in order to minimize yield uncertainty.

  • Converts One-third of the Sunlight into Electricity: 33.3 % Silicon-based Multi-junction Solar Cell

    Silicon-based multi-junction solar cell consisting of III-V semiconductors and silicon. The record cell converts 33.3. percent of the incident sunlight into electricity. © Fraunhofer ISE/Photo: Dirk Mahler

    Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with the company EV Group (EVG) have developed a new silicon-based multi-junction solar cell, which can convert exactly one-third of the incident sunlight into useful electricity. This newest result is now published in the renowned scientific magazine Nature Energy.

  • High Resolution Laser Structuring of Thin Films at LOPEC 2017

    Laser ablation of ITO on flexible PET substrate. Fraunhofer ILT, Aachen, Germany.

    Fraunhofer Institute for Laser Technology ILT will present laser processes for micro structuring of thin films at LOPEC 2017, trade fair for printed electronics in Munich, Germany. Innovative solutions for application fields like photovoltaics and thin film processing will be shown at COPT.NRW joint stand 405, hall B0, from March 29 to 30.

  • Key Enabling Technologies at HANNOVER MESSE 2017

    Needle with very sharp tip end (

    Within the new focus area MICRO-NANO-AREA, the IVAM Microtechnology Network and Deutsche Messe will pool the “Key Enabling Technologies” Micro- and Nanotechnology, MEMS, Photonics and Advanced Materials. With these technologies, production of structures, components and devices is becoming more precise, more reliable, more flexible and faster. The following exhibitors will present their product innovations on-site.

  • Low haze structures for transparent flexible electrodes by electrospinning processes

    When conductive materials are spun, flexible conductive transparent electrodes could be produced. Source: Bellhäuser

    For flexible electrodes INM - Leibniz Institute for New Materials is working with the process of electrospinning, a technique that produces ultra-fine fibers that are up to 100 times thinner than a human hair. When conductive materials are spun, flexible conductive transparent electrodes could be produced. These FTCEs have transparencies comparable to indium tin oxide with low haze less than two percent.

    Flexible, transparent, and conductive electrodes (FTCE) are a key enabling technology for the new generation of flexible, printable and wearable electronics. The touchscreens and displays of the future will be curved and flexible and integrated into cars, phones, or medical technology.

  • Molecules that Self-assemble into Monolayers for Efficient Perovskite Solar Cells

    The molecule organises itself on the electrode surface until a dense, uniform monolayer is formed. HZB/Saule Magomedoviene

    A team at the HZB has discovered a new method for producing efficient contact layers in perovskite solar cells. It is based on molecules that organise themselves into a monolayer. The study was published in Advanced Energy Materials and appeared on the front cover of the journal. In recent years, solar cells based on metal halide perovskites have achieved an exceptional increase in efficiency. These materials promise cost-effective and flexible solar cells, and can be combined with conventional PV materials such as silicon to form particularly efficient tandem solar cells.

  • Multicrystalline Silicon Solar Cell with 21.9 % Efficiency: Fraunhofer ISE Again Holds World Record

    The multicrystalline world record solar cell made of n-type HPM silicon with an area of 2 cm x 2 cm. ©Fraunhofer ISE

    The potential of photovoltaics (PV) has not yet been exhausted. Both industry and research continue to work intensively on increasing the efficiency and reducing the costs of solar cells, the basic component of every PV power plant. Now researchers at Fraunhofer ISE have produced a multicrystalline silicon solar cell with 21.9 percent efficiency, successfully bringing the world record back to Freiburg. Higher efficiencies and optimized processing steps are decisive for decreasing the cost of solar electricity even further. Both of these are an integral part of the photovoltaic research at the Fraunhofer Institute for Solar Energy Systems.

  • Nanotechnology for energy materials: Electrodes like leaf veins

    SEM – model of a metallic nano-network with periodic arrangement ( left) and visual representation of a fractal pattern (right). Credit: M. Giersig/HZB

    Nano-sized metallic wires are attracting increasing attention as conductive elements for manufacturing transparent electrodes, which are employed in solar cells and touch screen panels. In addition to high electric conductivity, excellent optical transmittance is one of the important parameters for an electrode in photovoltaic applications.

  • New Materials – New Test Requirements

    The workshop “PV Module Reliability“ at Frauhofer ISE focuses on the durability of different PV technologies, for example, bifacial modules. Fraunhofer ISE

    7th PV Module Reliability Workshop Sets on the Future of the Solar Energy Market

    On July 6-7, 2017 the Fraunhofer Institute for Solar Energy Systems ISE is hosting the 7th PV Module Reliability workshop. This year the workshop will be held at the Solar Info Center, which is in close proximity to the laboratories of Fraunhofer ISE in Freiburg. The location provides an ideal setting for technical tours and discussions. This year the workshop focuses on the reliability of PV modules and systems, and speakers from throughout the world will be presenting talks related to this theme.

  • Photovoltaics and Photosynthesis

    The agrophotovoltaics (APV) pilot plant located in Heggelbach near Lake Constance couples the production of electricity and food crops ©Fraunhofer ISE

    Pilot Plant at Lake Constance Combines Electricity and Crop Production

    In 1981, an article by Prof. Adolf Goetzberger titled "Potatoes under the Collector" was published in the German magazine “Sonnenenergie”. The article proposed a particularly favorable setup for solar energy systems in combination with agricultural land use. After smoldering on the backburner for a couple of years, the concept of agrophotovoltaics (APV), that is, the dual usage of land for crop and electricity production, was again taken up by researchers at Fraunhofer ISE in 2011.

  • Photovoltaics: Easy Implementation Thanks to Modern Printing Techniques

    The printed stripes make all the difference. By series connection, each square of ten stripes is capable of producing a voltage of about 8 Volt. © Fraunhofer IAP

    Imagine a jacket that produces enough electricity to charge your mobile phone. Imagine a jacket that does not only reflect, but light up itself when you ride your bike in the dark. Innovative printing solutions make future happen today. The Fraunhofer Institute for Applied Polymer Research IAP presents different prototypes from photovoltaics research projects at the international exhibition and conference for the printed electronics industry LOPEC 2018 in Munich, March 13 to 15. First projects resulting from the German OLED Technology Alliance (GOTA) are being presented as well.

    Fraunhofer IAP at LOPEC: Hall B0 Booth 207

  • Printed in-situ Perovskite Solar Cells Save Resources and Can Be Produced Locally

    In-situ filling of a printed perovskite solar cell at Fraunhofer ISE. © Fraunhofer ISE

    Photovoltaics (PV) is one of the key technologies of a sustainable energy supply based on renewable energy. Besides silicon-based photovoltaics, which presently dominates the market, there are other materials, such as perovskite, that also show great potential. Scientists are testing the proof of concept of these new types of solar cells.

  • Reliability of TPedge PV Modules Successfully Tested

    TPedge module with 2 mm thick glass undergoing distributed load test.  ©Fraunhofer ISE

    The TPedge concept reduces the material and production costs of PV modules, since encapsulation foils and the lamination process are no longer needed. At the same time, the aging stability of the PV module increases appreciably. In the project “TPedge,” researchers at Fraunhofer ISE together with their partners have developed processes so that the innovative PV modules can be manufactured on an industrial scale.

  • Research at Fraunhofer ISE Investigates Integrated Photovoltaic Modules for Commercial Vehicles

    Principle of the vehicle-integrated PV modules for refrigerated semitrailers developped by Fraunhofer ISE. ©Fraunhofer ISE

    Thanks to considerable cost reductions in photovoltaic modules, solar energy holds increasing appeal for use in the mobility sector. Depending on the type of application, even diesel fuel for trucks can be replaced by photovoltaics to some extent. Fraunhofer ISE has carried out and evaluated yield analyses of PV power supply for commercial vehicles, such as refrigerated transport vehicles, using real-life solar irradiance data. Based on its findings, the institute sees great potential in this field and is working together with partners from the logistics and automotive sectors to conduct research into special PV modules for use in commercial vehicles.

  • Shedding light on light absorption: titanium dioxide unveiled

    Lattice structure of anatase TiO2 with a graphical representation of the 2D exciton that is generated by the absorption of light. This 2D exciton is the lowest energy excitation of the material.

    MPSD scientists have uncovered the hidden properties of titanium dioxide, one of the most promising materials for light-conversion technology. The anatase crystal form of Titanium dioxide (TiO₂) is one of the most promising materials for photovoltaic and photocatalytic applications nowadays. Despite years of studies on the conversion of light absorbed by anatase TiO₂, into electrical charges, the very nature of its fundamental electronic and optical properties remained still unknown. Scientists from the MPSD (Max Planck Institute for the Structure and Dynamics of Matter) at CFEL (Center for Free-Electron Laser Science) in Hamburg, together with their international partners at EPFL, Lausanne used a combination of cutting-edge steady-state and ultrafast spectroscopic techniques, as well as theoretical simulation tools to elucidate these fundamental properties of anatase TiO₂. Their work is published in Nature Communications.

  • Solar cells: Optimised growth and sawing of crystals

    The produced wafers are ready for the next steps on the path to the module.  © SolarWorld GmbH

    The market for photovoltaic systems is highly competitive. In order to achieve higher efficiency and reduce costs, manufacturers are continuously optimising the production processes. The new BINE-Projektinfo brochure "Cheaper production of solar cells" (02/2017) presents two improved production processes. The first makes it possible to produce quasi-monocrystalline silicon with a significantly lower energy requirement and at the same time obtain a very pure, high-quality silicon. The second reduces the material losses when the silicon ingots are sawn into many thin slices (wafers). The new sawing technology will enable more wafers to be obtained from the same amount of silicon.

  • The Role of Sodium for the Enhancement of Solar Cells

    Dr. Torsten Schwarz, postdoctoral researcher at the MPIE, analyzed the local clustering and gradients of sodium with the atom probe (seen in the image). Max-Planck-Institut für Eisenforschung GmbH

     

    Green energy gained by photovoltaic amounts ca. 6% of Germany’s gross power production . The most common solar cells currently used are made out of silicon. So-called CIGS, solar cells out of copper, indium, gallium and selen (Cu(In,Ga)(S,Se)2, are a promising alternative with an efficiency of ca. 23%, which is the conversion rate of light to electricity. In comparison to conventional silicon solar cells, CIGS consumes less material and production energy and are thus cheaper in production and environmentally friendly.

  • Transporting more electricity through new lines

    Both the wires in the core and the aluminium zirconium wires in the jacket contribute to the tensile strength.  © 3M Deutschland GmbH

    The volume of electricity generated by wind energy and photovoltaic systems is increasing in the German power grid. This electricity has to be transported over long distances to urban areas and industrial centres. Newly developed high-temperature conductors now offer a way of increasing the maximum power capacity that can be transmitted through existing power lines. The BINE Projektinfo brochure entitled "The hotline in the grid" (13/2016) presents the new transmission lines. With a comparable conductor cross-section, these can almost double the transport capability of existing transmission lines.