Category Technology/Electronics

Image of photonic hypercrystals courtesy of Tal Galfsky

Control of light-matter interaction is central to fundamental phenomena and technologies such as photosynthesis, lasers, LEDs and solar cells. City College of New York researchers have now demonstrated a new class of artificial media called photonic hypercrystals that can control light-matter interaction in unprecedented ways. This could lead to such benefits as ultrafast LEDs for Li-Fi (a wireless technology that transmits high-speed data using visible light communication), enhanced absorption in solar cells and the development of single photon emitters for quantum information processing, said Vinod M. Menon, professor of physics in City College’s Division of Science.

Photonic crystals and metamaterials are two of the most well-known...

1. View into the 2.1-kilometre long accelerator tunnel of European XFEL with the yellow superconducting accelerator modules hanging from the ceiling (photo: DESY/D. Nölle) 2. First Laser Light at the European XFEL, recorded by an X-ray detector at the end of the tunnel. Credit: DESY 3. The undulators gerenate the bright X-ray light. Credit: European XFEL/Heiner Müller-Elsner

European XFEL reaches the last big milestone before the official opening. The 3.4 km long facility, most of which is located in underground tunnels, has generated its first X-ray laser light. The X-ray light has a wavelength of 0.8 nm – about 500 times shorter than that of visible light. At first lasing, the laser had a repetition rate of one pulse per second, which will later increase to 2

7,000 per second.

Europe...

Schematic of the pathway describing the evolution of adsorbed ethene (top left) to graphene (bottom left). The sequence of intermediates identified in the study and their respective appearance temperatures are indicated. Credit: F. Esch, R. Schaub, U. Landman

An international has developed a new way to produce single-layer graphene from a simple precursor: ethene aka ethylene – the smallest alkene molecule, which contains just two atoms of carbon. By heating the ethene in stages to a temperature of slightly >700C – hotter than had been attempted before – the researchers produced pure layers of graphene on a rhodium catalyst substrate. The stepwise heating and higher temperature overcame challenges in earlier efforts to produce graphene directly from hydrocarbon precursors.

Because of its l...

Scientists have developed a new molybdenum-coated catalyst that prevents an unwanted back reaction in certain chemical systems that split water into hydrogen and oxygen. (Andy Freeberg/SLAC National Accelerator Laboratory)

Hydrogen is one of the most promising clean fuels for use in cars, houses and portable generators. But water-splitting systems require a very efficient catalyst. Now an international research team, including scientists at DOE SLAC National Accelerator Laboratory, has developed a new catalyst with a molybdenum coating that prevents this problematic back reaction and works well in realistic operating conditions...