Solar cell

  • 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.

  • Rolling out solar cells: German-Danish project researches flexible organic energy technologies

    In the long run, flexible solar cells could be produced on a large scale by roll-to-roll printing presses. Photo/Copyright: NanoSYD

    Solar cells as thin as foil, and so flexible that they can be rolled out over various large surfaces such as house and vehicle roofs or glass fronts – that is one of the long-term goals of a German-Danish research project that is starting now. Those involved in the “RollFlex Innovation Project Centre” include the University of Southern Denmark (SDU), where the project is headquartered, Kiel University (CAU), the CAU-based start-up FUMT R&D Functional Materials GmbH, the Danish company Stensborg A/S, as well as numerous German and Danish network partners. The official kick-off event took place last week (Wednesday 14 December) in Sonderborg.

  • Silicon solar cell of ISFH yields 25% efficiency with passivating POLO contacts

    Monocrystalline 25%-silicon solar cell with POLO-contacts for both polarities on the rear side of the solar cell. ISFH

    The Lower Saxon‘ Institute for Solar Energy Research Hamelin (ISFH) achieved a solar cell efficiency of 25 % in collaboration with the Institute of Electronic Materials and Devices (MBE) of the Leibniz Universität Hannover. This high efficiency was accomplished with passivating "poly-Si on oxide" contacts (POLO) for both polarities, which avoid the otherwise high recombination beneath the metal contacts. The Lower Saxon‘ Institute for Solar Energy Research Hamelin (ISFH), an affiliated institute of the “Leibniz Universität Hannover” in collaboration with the Institute of Electronic Materials and Devices (MBE) of the “Leibniz Universität Hannover” achieved a solar cell efficiency of 25 %. This result was confirmed by DAkkS-accredited independent calibration laboratory ISFH CalTeC and presented at the Asian conference PVSEC-26 in Singapore.