12 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...

CPMU17_EMIL - Hard x-ray EMIL Beamline

The CPMU17_EMIL - Hard x-ray EMIL Beamline uses a planar cryogenic in-vacuum undulator to cover the photon energy range from 700-10000eV. A toroidal mirror M1 collimates (vertically) and focusses (horizontally) the U17 beam, which is then diffracted either by a double crystal monochromator (DCM, with crystal pairs Si 111, Si 311, Si 422 selectable) or passed to a plane grating monochromator (PGM) equipped with two blazed gratings (400 and 800 l/mm). A switching mirror unit...

OAESE - Operando Absorption and Emission Spectroscopy at EMIL

In the Energy Materials In-situ Laboratory Berlin (EMIL) at the BESSY II synchrotron facility, we have set up an infrastructure that allows x-ray absorption spectroscopic (NEXAFS) studies of energy materials under operating conditions. This setup is based on a three-electrode electrochemical liquid flow-cell attached to an ultra-high vacuum chamber (UHV) dedicated for in-situ/operando studies. To isolate the cell environment containing liquid electrolyte from the UHV of the analysis chamber, a very thin (about 100 nm)...

PEAXIS - Combined RIXS and XPS

The station PEAXIS (PhotoElectron Analysis and X-ray Inelastic Spectroscopy) is a fixed station installed at the U41-PEAXIS beamline. It is dedicated to studies of angle-resolved RIXS (Resonant Inelastic X-ray Scattering) and PES (PhotoElectron Spectroscopy) on solids. The station is equipped with an electron energy analyzer and a RIXS spectrometer. Various sample manipulators can be installed in the sample chamber. The RIXS arm is continuously rotatable on a supporting rail in a range of 106 degrees.

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...

UE48_EMIL - Soft x-ray EMIL Beamline

The UE48_EMIL soft x-ray EMIL Beamline uses an APPLE II undulator with full polarization control to cover the photon energy range ~80eV-1800eV. A toroidal mirror M1 collimates (vertically) and focusses (horizontally) the UE48 beam onto the exit slit. The radiation is dispersed by a plane grating monochromator equipped with two blazed gratings (400 and 800 l/mm). A switching mirror unit M3 with two cylindrical mirrors deflects the beam to the SISSY-I endstation and SISSY-II open...

SISSY I@EMIL

The EMIL x-ray beamline has two branches – UE48_EMIL - Soft x-ray EMIL Beamline (80 eV – 1800 eV) and CPMU17_EMIL - Hard x-ray EMIL Beamline (1800 eV – 10 keV) – that converge at the SISSY I endstation. The endstation features an angle-resolved photoelectron analyzer for PES/HAXPES and fluorescence detectors for XAS. A motorized 5-axis manipulator handle samples ranging from <1cm^2 to 6″ round and allows heating to ~1200°C as well as liquid N2...

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....

U41-PEAXIS - PEAXIS - Combined RIXS and XPS

U41-PEAXIS beamline is one of the highest flux beamlines at BESSY II. It provides highly focused soft X-rays, thanks to the ellipsoidal refocusing mirror. The beamline is connected to a fixed endstation PEAXIS that is dedicated to studies of angle-resolved RIXS (Resonant Inelastic X-ray Scattering) and PES (PhotoElectron Spectroscopy) on solids.

SISSY-off SR

The off-synchrotron analysis chamber is equipped with a lab-based non-monochromatized twin anode (Mg, Al) x-ray and a gas-discharge UV source for photoemission experiments. A motorized 5-axis manipulator handle samples ranging from <1cm^2 to 6″ round and allows heating to ~1200°C as well as liquid N2 cooling. Multiple electrical contacts can be made to samples for operando measurements. The analysis chamber is attached to an extensive UHV “backbone” containing the SISSY I endstation and large-scale deposition...

Registration Year

  • 2021
    12

Resource Types

  • Other
    7
  • Dataset
    5

Affiliations

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