A research group at Japan’s National Institute for Materials Science has developed a method for creating a bandgap in graphene oxide by changing the bonding state of carbon atoms that compose graphene through reversible absorption and desorption of oxygen atoms on the graphene. This allows in situ bandgap tuning, which could help develop high-performance nanoscale devices using graphene oxide membranes.
Life science researchers regularly use transmission electron microscopy to study wet environments. Now, scientists at Pacific Northwest National Laboratory who are studying batteries have used the method to have applied it successfully to microscopically view electrodes while they are bathed in wet electrolytes, mimicking realistic conditions inside actual batteries.
According to new research at the Massachusetts Institute of Technology, graphene, under an extremely powerful magnetic field and at extremely low temperature, can effectively filter electrons according to the direction of their spin. This is something that cannot be done by any conventional electronic system and could render graphene suitable for exotic uses such as quantum computing.
The Ulsan National Institute of Science and Technology in Korea has developed a new method for the mass production of boron/nitrogen co-doped graphene nanoplatelets, which could lead to the fabrication of a graphene-based field-effect transistor with semiconducting nature. This opens up opportunities for practical use in electronic devices.
Lithium-ion batteries could have significantly higher energy density if their graphite anodes were to be replaced by lithium metal anodes. Hampering this change, however, has been the persistent growth of dendrites that eventually short-circuit the battery. Researchers have recently discovered that the bulk of dendrite material lies below the surface of the lithium electrode, underneath the electrode/electrolyte interface.
Stanene is the name given by researchers to 2-D sheets of tin that are only one atom thick. A Stanford Univ. team predicts stanene would be the first topological insulator to demonstrate zero heat dissipation properties at room temperature, conducting charges around its edges without any loss. Experiments are underway to create the material in the laboratory. If successful, stanene will enhance devices being built under a DARPA program.
With the help of the x-ray light source PETRA III, researchers in Germany have, for the first time, watched organic solar cells degrade in real time. This work could open new approaches to increasing the stability of this highly promising type of solar cell, which is known for its flexibility and low cost but has a short lifespan.
Transistors, the workhorses of the electronics world, are plagued by leakage current. This results in unnecessary energy losses, which is why smartphones and laptops, for example, have to be recharged so often. Researchers have recently shown that this leakage current can be radically reduced by “squeezing” the transistor with a piezoelectric material. Using this approach, they have surpassed the theoretical limit for leakage current.
Are electrons truly round? More specifically, is the electron’s charge between its poles uniform? A group at JILA has tackled this difficult question and has developed a method of spinning electric and magnetic fields around trapped molecular ions to measure the tiny electrons. They haven’t yet matched other electric dipole moment measurement techniques, but eventually the new method should surpass them.
In materials science, electric and magnetic effects have usually been studied separately. There are, however, extraordinary materials called “multiferroics”, in which electric and magnetic excitations are closely linked. Scientists in Austria have now shown in an experiment that magnetic properties and excitations can be influenced by an electric voltage.
Converting solar energy into storable fuel remains one of the greatest challenges of modern chemistry. Chemists have commonly tried to use indium tin oxide (ITO) because it has transparency, but it also expensive and rare. Researchers at Duke Univ. has created something they hope can replace ITO: copper nanowires fused in a see-through film.
In leaves, two proteins are responsible for photosynthesis, and they perform the conversion of carbon dioxide into oxygen and biomass very efficiently. Scientists have now harnessed this capability by embedding these proteins into complex molecules developed in the laboratory. Their bio-based solar cell creates electron current instead of biomass.
A new technique that allows curved surfaces to appear flat to electromagnetic waves has been developed by scientists in England. The discovery could hail a step-change in how antennas are tailored to each platform, which could be useful to a number of industries that rely on high performance antennas for reliable and efficient wireless communications.
New work by researchers at Univ. of California, Berkeley could soon transform the building blocks of modern electronics by making nanomagnetic switches a viable replacement for the conventional transistors found in all computers.
Researchers from North Carolina State Univ. have, for the first time, integrated a material called bismuth ferrite (BFO) as a single crystal onto a silicon chip, opening the door to a new generation of multifunctional, smart devices. Integrating the BFO into the silicon substrate as a single crystal makes the BFO more efficient by limiting the amount of electric charge that “leaks” out of the BFO into the substrate.
Ferroelectric materials are known for their ability to spontaneously switch polarization when an electric field is applied. An Oak Ridge National Laboratory-led team took advantage of this property to draw areas of switched polarization called domains on the surface of a ferroelectric material. To the researchers’ surprise, the domains began forming complex and unpredictable patterns that the researchers say should not be possible.
Batteries that power electric cars have problems. They take a long time to charge. The charge doesn’t hold long enough to drive long distances. They don’t allow drivers to quickly accelerate. They are big and bulky. By creating nanoparticles with controlled shape, engineers in California believe smaller, more powerful and energy-efficient batteries for vehicles can be built.
A team of scientists have demonstrated new application of graphene using positive feedback. Using graphene’s electrical conduction, Columbia Univ. engineers have created a nano-mechanical system that can create FM signals. It is, in effect, the world's smallest FM radio transmitter.
Tiny electrical wires protrude from some bacteria and contribute to rock and dirt formation. Pacific Northwest National Laboratory researchers studying the protein that makes up one such wire have determined the protein's structure and have shown that the protein's shape and form suggest possible ways for the bacteria to shuttle electrons along the nanowire.
Researchers from the Univ. of Pennsylvania and Drexel Univ. have experimentally demonstrated a new method for solar cell construction which may ultimately make them less expensive, easier to manufacture and more efficient at harvesting energy from the sun. The breakthrough, which is the result of five years of focused research, relies on specifically designed perovskite crystals that deliver a “bulk” photovoltaic effect.
Researchers at the Georgia Institute of Technology have recently demonstrated an integrated rhombic gridding based triboelectric nanogenerator, or “TENG”, that has been proven to be a cost-effective and robust approach for harvesting ambient environmental energy.
The Swiss Federal Institute of Technology in Lausanne’s new convention center, opening in April 2014, is being equipped with a glass façade composed of dye solar cells. The project, a world’s first for an exterior window, leverages the potential of dye-sensitive solar cells known as Graetzel cells, which are indifferent to the angle of incidence of light that hits them.
Univ. of Delaware materials scientists have successfully developed a compact, stretchable wire-shaped supercapacitor based on continuous carbon nanotube fibers. When subjected to a tensile strain of 100% over 10,000 charge/discharge cycles, the CNT supercapacitor’s electrochemical performance improved to 108%.
Researchers in Basque country in Spain have developed and patented a new source of light emitter based on boron nitride nanotubes. Suitable for developing high-efficiency optoelectronic devices, the structural defects in the nanotubes help make it extremely efficient in ultraviolet light emission.
Quantum dots are nano-sized semiconductor particles whose emission color can be tuned by simply changing their dimensions. New research at Los Alamos National Laboratory aims to improve quantum dot-based light-emitting diodes by using a new generation of engineered quantum dots tailored specifically to have reduced wasteful charge-carrier interactions that compete with the production of light.