9 Works

Supplement to: Machine learning classification for field distributions of photonic modes

Carlo Barth & Christiane Becker
Electromagnetic modes of photonic nanostructures can exhibit increased near-field energy densities which can be applied in many fields such as biosensing, quantum dot solar cells or photon upconversion. Optimizing such systems enforces to systematically analyze large amounts of numerically obtained three-dimensional field distribution data, as in the presented dataset. The simulated system is a silicon photonic crystal slab on glass (subspace) with a hexagonal lattice of cylindrical holes. The holes are filled with a medium...

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...

PanDDA-analyzed data of a crystallographic fragment screening of F2X-Universal Library vs. AR

Tatjana Barthel, Jan Wollenhaupt, Gustavo M. A. Lima, Markus C. Wahl & Manfred S. Weiss
A crystallographic fragment screening (CFS) has been performed on a spliceosomal yeast protein-protein complex of Aar2 and the RNaseH-like domain of Prp8 (AR). The F2X-Universal Library is a fragment library representing the commercially available chemical space of fragments. 917 fragments have been individually screened via crystal soaking. The datasets that could be successfully auto-processed and auto-refined had been subjected to a Pan-Dataset Density Analysis (PanDDA) (Pearce et al., 2017). This analysis allows to find low...

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...

Supplement to: Nano-optical designs for high efficiency monolithic perovskite-silicon tandem solar cells

Philipp Tockhorn, Johannes Sutter, Alexandros Cruz, Philipp Wagner, Klaus Jäger, Danbi Yoo, Felix Lang, Max Grischek, Bor Li, Jinzhao Li, Oleksandra Shargaieva, Eva Unger, Amran Al-Ashouri, Eike Köhnen, Martin Stolterfoht, Dieter Neher, Rutger Schlatmann, Bernd Rech, Bernd Stannowski, Steve Albrecht & Christiane Becker
Perovskite-silicon tandem solar cells allow to overcome the power conversion efficiency limit of conventional silicon solar cells. So far, various textured tandem devices have been presented aiming at improved optical performance, but optimal film growth on surface textured wafers remains challenging. Here we present perovskite-silicon tandem solar cells with periodic nanotextures that offer various advantages without compromising the material quality of solution-processed perovskite layers. We show the reduction of reflection losses in comparison to planar...

Neutron study of the topological flux model of hydrogen ions in water ice

J.-U. Hoffmann, K. Siemensmeyer, S. Isakov, D. J. P. Morris, B. Klemke, I. Glavatskyi, K. Seiffert, D. A. Tennant, S. Sondhi & R. Moessner
The familiarity of water ice means we often overlook its non-trivial character illustrated, for example, by the many snowflake morphologies resulting from disordered combinations of covalent and hydrogen bonds between hydrogen and oxygen atoms in water ice’s most common phase (Ih) that keep the H_2 O molecular character. Using neutron diffraction on the flat-cone diffractometer E2 at BER-II, Helmholtz-Zentrum Berlin, we probe the atomic scale configuration in the Ih phase of water ice to test...

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

  • 2022
  • 2021
  • 2018

Resource Types

  • Dataset


  • 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
  • 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
  • Xavier University, Department of Physics, 3800 Victory Parkway, Cincinnati, OH 45207, USA
  • Dept. of Physics, Princeton University, Washington Road, Princeton, NJ 08544, USA
  • Berliner Hochschule für Technik, 13353 Berlin
  • Google Inc., Brandschenkestrasse 110, 8002 Zürich, Switzerland
  • Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, 01187 Dresden, Germany
  • Institut de Systématique, Évolution, Biodiversité (UMR 7205), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, 75005 Paris, France