5 Works

Optimizing metal grating back reflectors for III-V-on-silicon multijunction solar cells

Peter Tillmann, Benedikt Bläsi, Sven Burger, Martin Hammerschmidt, Oliver Höhn, Christiane Becker & Klaus Jäger
Multi-junction solar cells allow to utilize sunlight more effectively than single junction solar cells. In our work, we present optical simulations of III-V-on-silicon solar cells with a metal grating at the back, which experimentally have reached more than 33% power conversion efficiency. First, we perform simulations with the finite element method and compare them with experimental data to validate our model. We find that accurately modeling the investigated geometrical structure is necessary for best agreement...

Using the photo-induced L_3 resonance shift in Fe and Ni as time reference for ultrafast experiments at low flux soft X-ray sources

Somnath Jana, Shreyas Muralidhar, Johan Åkerman, Christian Schüßler-Langeheine & Niko Pontius
We study the optical-pump induced ultrafast transient change of the X-ray absorption at the L_3 absorption resonances of the transition metals Ni and Fe in Fe_{0.5}Ni_{0.5} alloy. We find the effect for both elements to occur simultaneously on a femtosecond timescale. This effect may hence be used as a handy cross-correlation scheme providing a time-zero reference for ultrafast optical-pump soft X-ray-probe measurement. The method benefits from a relatively simple experimental setup as the sample itself...

Optical simulations of nanotextured perovskite/silicon tandem solar cell

Klaus Jäger, Johannes Sutter, Philipp-Immanuel Schneider, Martin Hammerschmidt & Christiane Becker
Perovskite/silicon tandem solar cells (PSTSC) are amongst the most promising routes to increase the power conversion efficiency (PCE) of silicon-based solar cells. Many of the highly efficiency PSTSC use planar perovskite top cell layer stacks because of the compatibility with solution processing, which is the preferred fabrication process for perovskite solar cells. However, light management can further improve the optical performance of PSTSC. For example, smooth nanotextures can help to reduce reflective losses and increase...

Focused Ion Beam tomography on fossilized osteocytes

Yara Haridy, Markus Osenberg, André Hilger, Ingo Manke, Donald Davesne & Florian Witzmann
Osteocytes play a central role in bone metabolism in extant vertebrates, but their evolutionary history is poorly understood. Therefore osteocyte lacunae microstructure of fossil bone was studied on the nanometer scale by means of focused ion beam tomography (FIB). A osteostracan and a “placoderm” were imaged, the earliest groups with cellular bone, and secondary osteons respectively. To visualize and characterize the early bone composition via the morphology and distribution of osteocyte lacunae, thereby imaging the...

3D Neutron Computed Laminography of Maize Plants

Nicole Rudolph-Mohr, Sarah Bereswill, Christian Tötzke, Nikolay Kardjilov & Sascha E. Oswald
Plant root systems induce biogeochemical patterns in the soil by respiration, water uptake and root exudation that can be measured with in-situ imaging techniques. Slab-shaped rhizoboxes represent the optimum design for 2D optical fluorescence imaging of pH and oxygen dynamics in the rhizosphere as well as measurement of soil water content by neutron radiography. However, quality of standard tomographic (3D) imaging of laterally extended samples suffers from insufficient neutron transmission over a significant angular range....

Registration Year

  • 2021

Resource Types

  • Dataset


  • Optics for Solar Energy, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 16, 12489 Berlin
  • Computational Nano Optics, Zuse Institute Berlin, Takustraße 7, 14195 Berlin
  • Institut de Systématique, Évolution, Biodiversité (UMR 7205), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, 75005 Paris, France
  • Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden
  • Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, 12489 Berlin, Germany
  • Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
  • Institute of Applied Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
  • Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg, Germany
  • Institute of Environmental Science and Geography, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
  • Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, 10115 Berlin, Germany