Drawn relentlessly by their electrical charges, lithium ions in a battery surge from anode to cathode and back again. Yet, no one really understands what goes on at the atomic scale as lithium ion batteries are used and recharged. Using transmission electron microscopy, researchers are now glimpsing what can happen to anodes as lithium ions work their way into them. The “atomic shuffling” these ions perform leads to rapid anode failure.
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Researchers from the Univ. of Texas at Dallas have created technology that could be the first step toward wearable computers with self-contained power sources or, more immediately, a smartphone that doesn’t die after a few hours of heavy use. This technology taps into the power of a single electron to control energy consumption inside transistors, which are at the core of most modern electronic systems.
Blue organic light-emitting diodes (OLEDs) are one of a trio of colors used in OLED displays such as smartphone screens and high-end TVs. In a step that could lead to longer battery life in smartphones and lower power consumption for large-screen televisions, researchers at the Univ. of Michigan have extended the lifetime of blue organic light emitting diodes by a factor of 10.
Princeton Univ. researchers have developed a new method to increase the power and clarity of light-emitting diodes (LEDs). Using a new nanoscale structure made from flexible carbon-based sheet, the researchers increased the brightness and efficiency of LEDs made of organic materials by 57%.
A common complaints about solar power is that solar panels are still too expensive. Efforts at making them more efficient or longer-lasting have been limited. A new method developed in Okinawa could solve the expense problem: A hybrid form of deposition is being used to create perovskite solar cells from a mixture of inexpensive organic and inorganic raw materials, eliminating the need for expensive crystallized silicon.
An international team of physicists has shown that information stored in the nuclear spins of hydrogen isotopes in an organic light-emitting diode (LED) or organic LED can be read out by measuring the electrical current through the device. Unlike previous schemes that only work at ultracold temperatures, this is the first to operate at room temperature, and could be used to create extremely dense and highly energy-efficient memory devices.
Donald Sadoway and his colleagues at the Massachusetts Institute of Technology have already started a company to produce electrical-grid-scale liquid batteries, whose layers of molten material automatically separate due to their differing densities. But a newly developed formula substitutes different metals for the molten layers. The new formula allows the battery to work at a much lower temperature.
A collaboration between scientists in the Univ. of Chicago’s chemistry department, the Institute for Molecular Engineering and Argonne National Laboratory has produced the highest-ever recorded efficiency for solar cells made of two types of polymers and fulllerene. Researchers identified a new polymer that improved the efficiency of solar cells and also determined the method by which the polymer improved the cells’ efficiency.
For decades, the power conversion efficiency of organic solar cells was hampered by the drawbacks of commonly used metal electrodes, including their instability and susceptibility to oxidation. Now for the first time, researchers at the Univ. of Massachusetts Amherst have developed a more efficient, easily processable and lightweight solar cell that can use virtually any metal for the electrode, effectively breaking the “electrode barrier.”
Combining materials that exhibit magnetic and ferroelectric properties could be a boon for electronics designs, revolutionizing logic circuits and jumpstarting spintronics. This task has proven difficult until a recently developed inorganic synthesis technique, created by chemists at The City College of New York, produced a new complex oxide that demonstrate both properties.
Typically a highly conductive material, graphene becomes a semiconductor when prepared as an ultra-narrow ribbon. Recent research has now developed a new method to selectively dope graphene molecules with nitrogen atoms. By seamlessly stringing together doped and undoped graphene pieces, ”heterojunctions” are formed in the nanoribbons, allowing electric current to flow in only one direction when voltage is applied.
A flexible display incorporating graphene in its pixels’ electronics has been successfully demonstrated by the Cambridge Graphene Centre and Plastic Logic. The new prototype is an active matrix electrophoretic display, similar to the screens used in today’s e-readers, except it is made of flexible plastic instead of glass. This advance marks the first time graphene has been used in a transistor-based flexible device.
A team of U.S. and Swiss researchers have built a new basic model circuit consisting of a silver nanowire and a single-layer flake of molybdenum disulfide. This new combination of materials can efficiently guide electricity and light along the same tiny wire, a finding that could be a step towards building computer chips capable of transporting digital information at the speed of light.
When metallic lithium forms and deposits during the charging process in a lithium-ion battery, it can lead to a reduced battery lifespan and even short circuits. Using neutron beams, scientists have now peered into the inner workings of a functioning battery without destroying it. In the process, they have resolved this so-called lithium plating mystery.
Physicists studying the effects of embedding magnetic spins onto the surface of a superconductor recently report that the spins can interact differently than previously thought. This hybrid platform could be useful for quantum simulations of complex spin systems, having the special feature that the interactions may be controllable, something quite unusual for most condensed matter systems.
Sensors made with copper could be cheap, light, flexible and highly conductive. Making such concepts affordable enough for general use remains a challenge but a new way of working with copper nanowires and a PVA “nano glue” could be a game-changer. Engineers in Australia have found a way of making flexible copper conductors cost-effective enough for commercial applications.
Electronic devices with unprecedented efficiency and data storage may someday run on ferroelectrics—remarkable materials that use built-in electric polarizations to read and write digital information, outperforming the magnets inside most popular data-driven technology. But ferroelectrics must first overcome a few key stumbling blocks, including a curious habit of "forgetting" stored data.
Researchers at the National Physical Laboratory in the U.K. have discovered that the conductivity at the edges of graphene devices is different to the central material. The group used local scanning electrical techniques to examine the local nanoscale electronic properties of epitaxial graphene, in particular the differences between the edges and central parts of graphene Hall bar devices.
Graphene has excellent biocompatibility thanks to its great flexibility and chemical durability, and its conducting properties suggest uses for prosthetic devices in humans. Physicists are now developing key components of an artificial retina made of graphene. These retina implants may one day serve as optical prostheses for blind people whose optical nerves are still intact.
Sun, wind and other renewable energy sources could make up a larger portion of the electricity America consumes if better batteries could be built to store the intermittent energy for cloudy, windless days. Now a new material could allow more utilities to store large amounts of renewable energy and make the nation's power system more reliable and resilient.
Graphene has become a focus of research on a variety of potential uses. Now researchers at Massachusetts Institute of Technology have found a way to control how the material conducts electricity by using extremely short light pulses, which could enable its use as a broadband light detector.
Using a new method to track the electrochemical reactions in a common electric vehicle battery material under operating conditions, scientists at Brookhaven National Laboratory have revealed new insight into why fast charging inhibits this material's performance. The study also provides the first direct experimental evidence to support a particular model of the electrochemical reaction.
In a recent paper, a team at Stanford Univ. which includes materials science expert Yi Cui and 2011 R&D Magazine Scientist of the Year Steven Chu report that they have taken a big step toward accomplishing what battery designers have been trying to do for decades: design a pure lithium anode.
Research led by Penn State Univ. and Cornell Univ. physicists is studying "spintorque" in devices that combine a standard magnetic material with a new material known as a topological insulator. The new insulator, which is made of bismuth selenide and operates at room temperature, overcomes one of the key challenges to developing a spintronics technology based on spin-orbit coupling.
The doubling of transistors on a microprocessor occurs roughly every two years, and is the outcome of what is called Moore’s Law. In a bid to continue this trend of decreasing transistor size and increasing computation and energy efficiency, chip-maker Intel has partnered with Lawrence Berkeley National Laboratory to design an entirely new kind of photoresist, one that combines the best features of two existing types of resist.
Perovskites continue to entice materials scientists with their mix of conductivity, ferroelectricity, ferromagnetism, and catalytic activity. In recent years, scientists realized that they could vastly improve the properties of perovskites by assembling them into thin films, but nobody knew the reason why. But studying the chemistry layer-by-layer, experts working with x-ray beamline at Argonne National Laboratory are getting close.
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