Jian Shi Research Group engineers material into promising optoelectronic. Optoelectronic materials that are capable of converting the energy of light into electricity, and electricity into light, have promising applications as light-emitting, energy-harvesting, and sensing technologies. However, devices made of these materials are often plagued by inefficiency, losing significant useful energy as heat. To break the current limits of efficiency, new principles of light-electricity conversion are needed. For instance, many materials that exhibit efficient optoelectronic properties are constrained by inversion symmetry,…
‘Every droplet effectively removed from indoor air would eliminate a potential source of transmission’. Although plexiglass barriers are seemingly everywhere these days — between grocery store lanes, around restaurant tables and towering above office cubicles — they are an imperfect solution to blocking virus transmission. Instead of capturing virus-laden respiratory droplets and aerosols, plexiglass dividers merely deflect droplets, causing them to bounce away but remain in the air. To enhance the function of these protective barriers, Northwestern University researchers have…
A new high-performance plastic foam developed from whey proteins can withstand extreme heat better than many common thermoplastics made from petroleum. A research team in Sweden reports that the material, which may be used for example in catalysts for cars, fuel filters or packaging foam, actually improves its mechanical performance after days of exposure to high temperatures. Reporting in Advanced Sustainable Systems, researchers from KTH Royal Institute of Technology in Stockholm say the research opens the door to using protein-based…
Researchers of the 3D matter made to order cluster of excellence use rotons for metamaterials – Nature Communications publishes first results. Acoustic waves in gases, liquids, and solids usually travel at an almost constant speed of sound. So-called rotons are an exception: their speed of sound changes significantly with the wavelength, and it is also possible that the waves travel backwards. Researchers at Karlsruhe Institute of Technology (KIT) are studying the possibilities of using rotons in artificial materials. These computer-designed…
A new technology could dramatically improve the safety of lithium-ion batteries that operate with gas electrolytes at ultra-low temperatures. Nanoengineers at the University of California San Diego developed a separator–the part of the battery that serves as a barrier between the anode and cathode–that keeps the gas-based electrolytes in these batteries from vaporizing. This new separator could, in turn, help prevent the buildup of pressure inside the battery that leads to swelling and explosions. “By trapping gas molecules, this separator…
Imaging technique could enable new pathways for reducing concrete’s hefty carbon footprint, as well as for 3-D printing of concrete. The concrete world that surrounds us owes its shape and durability to chemical reactions that start when ordinary Portland cement is mixed with water. Now, MIT scientists have demonstrated a way to watch these reactions under real-world conditions, an advance that may help researchers find ways to make concrete more sustainable. The study is a “Brothers Lumière moment for concrete…
Biofunctionalized materials… In general, plastics are processed at way over a hundred degrees Celsius. Enzymes, by contrast, cannot usually withstand these high temperatures. Researchers at the Fraunhofer Institute for Applied Polymer Research IAP have managed to reconcile these contradictions: They are able to embed enzymes in plastics without the enzymes losing their activity in the process. The potentials this creates are enormous. Materials that clean themselves, have anti-mold surfaces or are even self-degrading are just a few examples of what…
Developing new ultrathin metal electrodes has allowed researchers to create semitransparent perovskite solar cells that are highly efficient and can be coupled with traditional silicon cells to greatly boost the performance of both devices, said an international team of scientists. The research represents a step toward developing completely transparent solar cells. “Transparent solar cells could someday find a place on windows in homes and office buildings, generating electricity from sunlight that would otherwise be wasted,” said Kai Wang, assistant research…
Anyone who thinks of research laboratories only in terms of protective suits and clean rooms is not quite right: Since April, patterns, seams and mannequins have not been uncommon in the new Textile Prototyping Lab (TPL) at Fraunhofer IZM in Berlin. With the TPL, there is now a place where creative high-tech textiles are produced and which already distinguishes itself from the style of usual research laboratories by its design. As a collaborative project with the Weißensee Kunsthochschule Berlin, textile-integrated…
Using the circular vibration of surface acoustic waves, a collaborative research group have successfully controlled the magnetization of a ferromagnetic thin film. Their research was published in the journal Nature Communications on May 10, 2021. Essentially, acoustic waves are waves of atomic vibrations in a substance. When the waves propagate across the surface of a material, the vibration becomes circular. This circular motion, known as angular momentum, can help measure rotational motion. Surface acoustic waves are utilized in bandpass filters…
Comprehensive electronic-structure methods review featured in Nature Materials. Over the past 20 years, first-principles simulations have become powerful, widely used tools in many, diverse fields of science and engineering. From nanotechnology to planetary science, from metallurgy to quantum materials, they have accelerated the identification, characterization, and optimization of materials enormously. They have led to astonishing predictions–from ultrafast thermal transport to electron-phonon mediated superconductivity in hydrides to the emergence of flat bands in twisted-bilayer graphene– that have gone on to inspire…
McGill University researchers gain new insight into the workings perovskites that could lead to more efficient and cheaper solar cells. Researchers at McGill University have gained new insight into the workings of perovskites, a semiconductor material that shows great promise for making high-efficiency, low-cost solar cells and a range of other optical and electronic devices. Perovskites have drawn attention over the past decade because of their ability to act as semiconductors even when there are defects in the material’s crystal…
With brilliant colors and picturesque shapes, many crystals are wonders of nature. Some crystals are also wonders of science, with transformative applications in electronics and optics. Understanding how best to grow such crystals is key to further advances. Scientists from the U.S. Department of Energy’s (DOE) Argonne National Laboratory, along with three universities, have revealed new insights into the mechanism behind how gallium nitride crystals grow at the atomic scale. Gallium nitride crystals are already in wide use in light-emitting…
A new class of membranes promises highly interesting applications in material separation, whether in biotechnology or water purification. The theoretical understanding of these polymer membranes is, however, still incomplete. Two researchers from Helmholtz-Zentrum Hereon and the University of Göttingen now present a study, published in the renowned science journal Chemical Reviews, that identifies these gaps in knowledge and shows promising approaches toward solving them. Whether in desalination, water purification or CO2 separation, membranes play a central role in technology. The…
Chiral-spin rotation found in non-collinear antiferromagnet. Researchers at Tohoku University and the Japan Atomic Energy Agency (JAEA) have discovered a new spintronic phenomenon – a persistent rotation of chiral-spin structure. Their discovery was published in the journal Nature Materials on May 13, 2021. Tohoku University and JAEA researchers studied the response of chiral-spin structure of a non-collinear antiferromagnet Mn3Sn thin film to electron spin injection and found that the chiral-spin structure shows persistent rotation at zero magnetic field. Moreover, their…
Phase transformation mechanisms and kinetics of a metallic glass defined over a wide temperature range. Metallic glasses are metastable materials characterised by special atomic arrangement and properties. They are generally harder, more corrosion resistant and stronger than ordinary metals. Their amorphous structure is formed when natural crystallisation is prevented. This can be achieved, for example, by rapidly cooling the melt so that the atoms are deprived of mobility before they can adopt the crystal arrangement. The reverse process – rapid…
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