This unusual electronic energy structure could be harnessed for technologies of interest in quantum information science and electronics. Electrons in a solid occupy distinct energy bands separated by gaps. Energy band gaps are an electronic “no man’s land,” an energy range where no electrons are allowed. Now, scientists studying a compound containing iron, tellurium, and selenium have found that an energy band gap opens at a point where two allowed energy bands intersect on the material’s surface. They observed this…
Superconductivity is a complete loss of electrical resistance. Superconductors are not merely very good metals: it is a fundamentally different electronic state. In normal metals, electrons move individually, and they collide with defects and vibrations in the lattice. In superconductors, electrons are bound together by an attractive force, which allows them to move together in a correlated way and avoid defects. In a very small number of known superconductors, the onset of superconductivity causes spontaneous electrical currents to flow. These…
University of Pittsburgh chemical engineers replicate “swarmalator” behavior in chemical sheets. During the swarming of birds or fish, each entity coordinates its location relative to the others, so that the swarm moves as one larger, coherent unit. Fireflies on the other hand coordinate their temporal behavior: within a group, they eventually all flash on and off at the same time and thus act as synchronized oscillators. Few entities, however, coordinate both their spatial movements and inherent time clocks; the limited…
Piezoelectric wood Ingo Burgert and his team at Empa and ETH Zurich has proven it time and again: Wood is so much more than “just” a building material. Their research aims at extending the existing characteristics of wood in such a way that it is suitable for completely new ranges of application. For instance, they have already developed high-strength, water-repellent and magnetizable wood. Now, together with the Empa research group of Francis Schwarze and Javier Ribera, the team has developed…
Nanomaterials of perovskite dispersed in hexane and irradiated by laser; light emission by these materials is intense thanks to resistance to surface defects. Quantum dots are manmade nanoparticles of semiconducting material comprising only a few thousand atoms. Because of the small number of atoms, a quantum dot’s properties lie between those of single atoms or molecules and bulk material with a huge number of atoms. By changing the nanoparticles’ size and shape, it is possible to fine-tune their electronic and…
Two types of materials are better than one when it comes to solar cells, as revealed by an international team that has tested a new combination of materials and architecture to improve solar-cell efficiency. Silicon has long dominated as the premier material for solar cells, helped by its abundance as a raw material. However, perovskites, a class of hybrid organic-inorganic material, are a viable alternative due to their low-cost and large-scale manufacture and potentially higher performance. While still too unstable…
Efficient materials for future solar cells – New model to determine photoluminescence quantum efficiency. Photovoltaics decisively contributes to sustainable energy supply. The efficiency of solar cells in directly converting light energy into electrical energy depends on the material used. Metal-halide perovskites are considered very promising materials for solar cells of the next generation. With these semiconductors named after their special crystal structure, a considerable increase in efficiency was achieved in the past years. Meanwhile, perovskite solar cells have reached an…
Study shows how century-old design principle can be a pathway to overcoming failure. Catastrophic collapse of materials and structures is the inevitable consequence of a chain reaction of locally confined damage – from solid ceramics that snap after the development of a small crack to metal space trusses that give way after the warping of a single strut. In a study published this week in Advanced Materials, engineers at the University of California, Irvine and the Georgia Institute of Technology…
Fuel cells, which are attracting attention as an eco-friendly energy source, obtain electricity and heat simultaneously through the reverse reaction of water electrolysis. Therefore, the catalyst that enhances the reaction efficiency is directly connected to the performance of the fuel cell. To this, a POSTECH-UNIST joint research team has taken a step closer to developing high-performance catalysts by uncovering the ex-solution and phase transition phenomena at the atomic level for the first time. A joint research team of Professor Jeong…
An international team led by Artem R. Oganov, a Professor at Skoltech and MISIS, and Dr. Ivan Troyan from the Institute of Crystallography of RAS performed theoretical and experimental research on a new high-temperature superconductor, yttrium hydride (YH6). Their findings were published in the journal Advanced Materials. Yttrium hydrides rank among the three highest-temperature superconductors known to date. The leader among the three is a material with an unknown S-C-H composition and superconductivity at 288 K, which is followed by…
“Phase transitions” are a central phenomenon in physical sciences. Despite being technical-sounding, they are actually something we all experience in everyday life: ice melting into liquid water, or hot water evaporating as steam. Solid, liquid, and gas are three well known “phases” and, when one turns into another, that is a phase transition. Rare-earth nickelate oxides, also called nickelates, have attracted a lot of interest from researchers because they display an electronic phase transition, which may be exploited in future…
Until now, hexagonal boron nitride was considered the insulator of choice for miniaturized transistors — new investigations by TU Wien (Vienna) show: This may not be the way to go. For decades, there has been a trend in microelectronics towards ever smaller and more compact transistors. 2D materials such as graphene are seen as a beacon of hope here: they are the thinnest material layers that can possibly exist, consisting of only one or a few atomic layers. Nevertheless, they…
Scientists at the University of Tsukuba and the Institute of High Pressure Physics fabricate a novel molybdenum disulfide transistor and create an image of the spins of the electrons passing through which may open the way for new spintronic computers. Scientists from the University of Tsukuba and a scientist from the Institute of High Pressure Physics detected and mapped the electronic spins moving in a working transistor made of molybdenum disulfide. This research may lead to much faster computers that…
Researchers use sound to shape the future of printing. Researchers in the UK have developed a way to coax microscopic particles and droplets into precise patterns by harnessing the power of sound in air. The implications for printing, especially in the fields of medicine and electronics, are far-reaching. The scientists from the Universities of Bath and Bristol have shown that it’s possible to create precise, pre-determined patterns on surfaces from aerosol droplets or particles, using computer-controlled ultrasound. A paper describing…
Oxidative dispersion has been widely used in the regeneration of sintered metal catalysts as well as the fabrication of single-atom catalysts. The consensus on the oxidative dispersion process includes the formation of mobile metal oxide species from large metal particles and the capture of these species on a support surface. Nevertheless, the mechanism of oxidation-induced dispersion has yet to be confirmed via in situ electron microscopic and/or spectroscopic characterizations. Recently, a research team led by Prof. FU Qiang and Prof….
Columbia researchers engineer first technique to exploit the tunable symmetry of 2D materials for nonlinear optical applications, including laser, optical spectroscopy, imaging, and metrology systems, as well as next-generation optical quantum information processing and computing. Nonlinear optics, a study of how light interacts with matter, is critical to many photonic applications, from the green laser pointers we’re all familiar with to intense broadband (white) light sources for quantum photonics that enable optical quantum computing, super-resolution imaging, optical sensing and ranging,…
Feedback
