Crystallology

  • 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.

  • 3D printer inks from the woods

    Rod-like cellulose nanocrystals (CNC) approximately 120 nanometers long and 6.5 nanometers in diameter under the microscope. (Image: Empa)

    Empa researchers have succeeded in developing an environmentally friendly ink for 3D printing based on cellulose nanocrystals. This technology can be used to fabricate microstructures with outstanding mechanical properties, which have promising potential uses in implants and other biomedical applications.

    In order to produce 3D microstructured materials for automobile components, for instance, Empa researchers have been using a 3D printing method called “Direct Ink Writing” for the past year (DIW, see box). During this process, a viscous substance – the printing ink – is squeezed out of the printing nozzles and deposited onto a surface, pretty much like a pasta machine.

  • A Burst of ”Synchronous” Light

    Superlattices under the microscope (white light illumination). Empa

    Excited photo-emitters can cooperate and radiate simultaneously, a phenomenon called superfluorescence. Researchers from Empa and ETH Zurich, together with colleagues from IBM Research Zurich, have recently been able to create this effect with long-range ordered nanocrystal superlattices. This discovery could enable future developments in LED lighting, quantum sensing, quantum communication and future quantum computing. The study has just been published in the renowned journal "Nature".

  • Affordable detectors for gamma radiation

    single crystals made of lead halide perovskites Empa

    A research team at Empa and ETH Zurich has developed single crystals made of lead halide perovskites, which are able to gage radioactive radiation with high precision. Initial experiments have shown that these crystals, which can be manufactured from aqueous solutions or low-priced solvents, work just as well as conventional cadmium telluride semi-conductors, which are considerably more complicated to produce. The discovery could slash the price of many radio-detectors – such as in scanners in the security sector, portable dosimeters in power stations and measuring devices in medical diagnostics.

  • An Unlikely Marriage Among Oxides

    Sebastian Siol showing a sample of heterostructural oxides, which could be a promising coating for smart windows. Empa

    Sebastian Siol is looking for new materials with unusual properties that were so far not accessible in experiments. To do this, he connects partners who don't really fit together: One partner forces the other into a state that would not be possible without the unlikely pairing. Siol also makes sure that the crystal bonds last in everyday life. Only then are they interesting for industrial applications.

  • Chemists of TU Dresden Develop Highly Porous Material, More Precious than Diamonds

    The framework of DUT-60 holds a pore volume of 5.02 cm3g-1 – the highest specific pore volume one has ever measured among all crystalline framework materials so far. Dr. I. Senkovska, TU Dresden

    World Record of Cavities. Porosity is the key to high-performance materials for energy storage systems, environmental technologies or catalysts: The more porous a solid state material is, the more liquids and gases it is able to store. However, a multitude of pores destabilizes the material. In search of the stability limits of such frameworks, researchers of the TU Dresden’s Faculty of Chemistry broke a world record: DUT-60 is a new crystalline framework with the world’s highest specific surface and the highest specific pore volume (5.02 cm3g-1) measured so far among all known crystalline framework materials.

  • Das MPQ päsentiert den Original-Laser

    Prof. Theodore Maiman (Foto: K. Maiman)

    Im Jahr 1960 begann eine neue Ära der Technologiegeschichte. Theodore Maiman stellte den ers-ten funktionierenden Laser der Öffentlichkeit vor. Ein kleines Gerät bestehend aus einer Blitzlampe, einem Rubinkristall und einer Hülse aus Metall. Maimans erster Laser hat die Jahrzehnte überdauert. Jetzt ist das Original im Foyer des Max-Planck Instituts für Quantenoptik (MPQ) in Garching b. München in einer kleinen Ausstellung zu sehen. Zusammen mit dem Laser präsentiert das MPQ das Original-Laborbuch von Theodore Maiman mit seinen bahnbrechenden Skizzen des Geräts. Die Ausstellung ist ab dem 12. Dezember 2016 kostenlos zu besichtigen am Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str.1, 85748 Garching; täglich von 9 bis 17 Uhr. Journalisten sind herzlich zur Ausstellungseröffnung am 12. Dezember 2016 um 15 Uhr im Foyer des MPQ eingeladen.

  • Designing Nanocrystals for More Efficient Optoelectronics

    The luminescent atoms in the image show a nanocrystal which is characterized with atomistic resolution, including its interface chemistry. experimental and theoretical approaches. Published with permission by Nature Publishing Group. Copyright: Peter Allen

     

    New artificial materials for semiconductors used in solar cells or photoelectrochemical cells that are designed from scratch with totally new and tailored properties: this is the latest research topic of Stefan Wippermann, head of the group “Atomistic Modelling“ at the Max-Planck-Institut für Eisenforschung), and his team. They characterized for the first time with atomic resolution a typical material system and are able to set design principles.

  • Diamond Watch Components

    An anchor for a watch component made of single-crystal synthetic diamond. Schweizerischer Nationalfonds SNF

    SNSF-funded researchers have developed a new technique for carving materials to create micromechanical systems. In particular, they have created a miniscule watch component out of synthetic single-crystal diamond.

  • Electron highway inside crystal

    Step edges on topological crystalline insulators may lead to electrically conducting pathways where electrons with opposite spin spin move in converse directions - any U-turn is prohibited. Picture: Thomas Bathon/Paolo Sessi/Matthias Bode

    Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science. Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was highlighted again as the Royal Swedish Academy of Sciences in Stockholm awarded this year's Nobel Prize in Physics to three British scientists for their research of so-called topological phase transitions and topological phases of matter.

  • Faster, More Precise, More Stable: Study Optimizes Graphene Growth

    Visible to the naked eye: A wafer-thin graphene flake obtained via chemical vapor deposition. The red coloration of the copper substrate appears when the sample is heated in air. (Photo: J. Kraus/ TUM)

    Each atomic layer thin, tear-resistant, and stable. Graphene is seen as the material of the future. It is ideal for e.g. producing ultra-light electronics or highly stable mechanical components. But the wafer-thin carbon layers are difficult to produce. At the Technical University of Munich (TUM), Jürgen Kraus has manufactured self-supporting graphene membranes, and at the same time systematically investigated and optimized the growth of the graphene crystals. He was awarded the Evonik Research Prize for his work.

  • Good Vibrations Feel the Force

    Strong-field mid-infrared excitation allows to drive lattice vibrations of a crystal into the highly anharmonic regime which allows to reconstruct the interatomic potential. Joerg Harms, MPSD

    A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

  • How Magnetic Fields Can Fix Crystal Twinning

    Graphical representation of the magnetic interactions relevant to magnetic detwinning in EuFe₂As₂. Essential is the bi-quadratic coupling between Fe and Eu indicated by blue-red arrows. © Universität Augsburg/IfP/EKM

    Special coupling of magnetic moments in high-temperature superconductors allows to reorient crystalline domains leading to “perfect” single crystals. Augsburg/PhG/KPP – In many cases, it is important to be able to take measurements along different directions in the crystal lattice in order to study the physical properties of new materials, such as high-temperature superconductors.

  • How protons move through a fuel cell

    The experiments have been conducted with Barium ceric oxide. The crystal is non conductive in a dry state. When moisture comes in, the protons form OH-bondings and move through the crystal. Empa

    Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

    As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton conductivity is crucial for the latter; protons, i.e. positively charged hydrogen ions, are formed from hydrogen, which is used to power the fuel cell.

  • Imaging How Magnetism Goes Surfing

    Figure. Two examples of imaged strain and resulting magnetization configurations. ill.:/©: Michael Foerster, ALBA

    Using advanced dynamic imaging, researchers have been able to visualise deformation (sound) waves in crystals and measured the effect on nanomagnetic elements. This offers new low power magnetization manipulation for memory or logic applications and the methodology offers a new approach for analysing dynamic strains in other research fields: nanoparticles, chemical reactions, crystallography, etc.

  • Insights into closed enzymes

    Representation of electron density at the disulphide bond (yellow, between C56 and C163) and in its close vicinity. Prof. Michael Kovermann, University of Konstanz

    Scientists at the University of Konstanz and Umeå University in Sweden have arrived at a structural model of the enzyme adenylate kinase in its closed state.

    The adenylate kinase enzyme is crucial to managing the energy budget of cells, accelerating the biochemical process whereby energy is stored or released. The enzyme continuously changes between open and closed states. In its closed form, adenylate kinase is particularly active biochemically and thus able to accelerate the chemical reaction of “docked” molecules that it has encased like a clam. These are called ligands.

  • Kristalluntersuchung mit dreidimensionalen Beugungsmustern

    Kristalluntersuchung mit dreidimensionalen Beugungsmustern | Dreidimensionale Röntgenbeugungsmethode zur Bestimmung der kristallographischen Textur Abbildung: Wiley-VCH

    Trifft Röntgenstrahlung auf einen Kristall wird sie gebeugt und abgelenkt. Die sich daraus ergebenden Beugungsmuster werden auf einer Detektorfläche registriert und sind zweidimensionale Projektionen der Kristallstruktur. Diese Methode wird schon lange zur Strukturaufklärung genutzt. Forschern ist es nun gelungen dieser Projektion eine dritte Dimension hinzuzufügen: die Röntgenphotonenernergie.

  • Kristallzüchtung für komplexe Messaufgaben in der 5G-Technologie

    Kristallzüchtung für komplexe Messaufgaben in der 5G Technologie | Ferrit-Einkristalle für Hochfrequenz-Filterkomponenten gezüchtet aus Hochtemperaturlösungen Photo: INNOVENT e.V.

    Wissenschaftler der Industrieforschungseinrichtung INNOVENT züchten einkristalline Ferritmaterialien für die Mikrowellenmesstechnik. Erstmals werden damit durchgehende Empfangsbereiche von Signal- und Spektrumanalysatoren bis 85 GHz für anspruchsvolle Messaufgaben auf den Gebieten Automotive Radar, 5G und andere drahtlose Kommunikation realisiert.

  • Meteoriteneinschlag im Nano-Format

    Mit energiereichen Ionen lassen sich erstaunliche Nanostrukturen auf Kristalloberflächen erzeugen. Experimente und Berechnungen der TU Wien können diese Effekte nun erklären.

  • 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.