When a team of University of Illinois engineers set out to grow nanowires of a compound semiconductor on top of a sheet of graphene, they did not expect to discover a new paradigm of epitaxy. The self-assembled wires have a core of one composition and an outer layer of another, a desired trait for many advanced electronics applications.
By introducing high tensile strain, a research group in Switzerland has rendered germanium, which is normally unsuitable for lasers, capable of emitting 25 times more photons than in its relaxed state. This change alters the optical properties of the material and is enough to allow the construction of lasers from this material. This is valuable because germanium is highly compatible with silicon.
A local power failure in Ohio ten years ago caused a series of cascading power failures that resulted in a massive blackout. Such blackouts could be prevented in the future, thanks to a new piece of equipment developed by engineering researchers at the University of Arkansas. The device regulates or limits the amount of excess current that moves through the power grid when a surge occurs.
Researchers are developing a new type of semiconductor technology for future computers and electronics based on "2D nanocrystals" layered in sheets less than a nanometer thick that could replace today's transistors. The layered structure is made of a material called molybdenum disulfide, which belongs to a new class of semiconductors—metal di-chalogenides—emerging as potential candidates to replace today's CMOS technology.
The same material that formed the first primitive transistors more than 60 years ago can be modified in a new way to advance future electronics, according to a new study. Chemists at The Ohio State University have developed the technology for making a one-atom-thick sheet of germanium, and found that it conducts electrons more than ten times faster than silicon and five times faster than conventional germanium.
In a development that could make the advanced form of secure communications known as quantum cryptography more practical, University of Michigan researchers have demonstrated a simpler, more efficient single-photon emitter that can be made using traditional semiconductor processing techniques.
To increase the neutron detection efficiency of bulk-micromegas (MICRO-MEsh GAseous Structure) neutron detectors, researchers from China and the University of Tennessee-Knoxville have proposed three new types of thin-film converters: micro-channel, parallel micro-pillar, and oblique micro-pillar 2D array. When validated using Monte Carlo simulations, the latter design showed a threefold increase in neutron detection efficiencies.
Certain semiconductors, when imparted with energy, in turn emit light; they directly produce photons, instead of producing heat. This phenomenon is commonplace and used in light-emitting diodes, or LEDs. Research from the University of Pennsylvania has enabled "bulk" silicon to emit broad-spectrum, visible light for the first time, opening the possibility of using the element in devices that have both electronic and photonic components.
Researchers sponsored by Semiconductor Research Corporation (SRC) have developed a modeling process designed to simulate atomic-level etching with chemicals that are effective alternatives to widely used perfluorocarbon (PFC) gases. The novel approach will identify and evaluate green plasma chemistries for processing emerging memory/logic devices and through-silicon-via (TSV)-enabled technologies for the semiconductor industry.
Semiconducting polymers are an unruly bunch, but University of Michigan engineers have developed a new method for getting them in line that could pave the way for cheaper, greener, "paint-on" plastic electronics.
MEH-PPV is a low-cost polymer that can be integrated with silicon chips, and researchers have sought to use it to convert electricity into laser light for use in photonic devices. However, attempts to do this have failed because the amount of electricity needed to generate laser light in MEH-PPV was so high that it caused the material to degrade. Researchers have recently come up with a low-cost way to enhance MEH-PPV’s ability to confine light, protecting the material.
Bringing the concept of an “artificial leaf” closer to reality, a team of researchers at Massachusetts Institute of Technology has published a detailed analysis of all the factors that could limit the efficiency of such a system. The new analysis lays out a roadmap for a research program to improve the efficiency of these systems, and could quickly lead to the production of a practical, inexpensive and commercially viable prototype.
Recent research offers a new spin on using nanoscale semiconductor structures to build faster computers and electronics. Literally. Researchers have revealed a new method that better preserves the units necessary to power lightning-fast electronics, known as qubits. Hole spins, rather than electron spins, can keep quantum bits in the same physical state up to 10 times longer than before, the report finds.
Silicon dominates in microelectronics and photovoltaics industry, but has been considered unsuitable for light-emitting diodes for a long time. At the nanoscale, however, its properties change. Scientists in Germany and Canada have now succeeded in manufacturing silicon-based light-emitting diodes (SiLEDs) using silicon nanocrystals a few nanometers in size. They are free of heavy metals and can emit light in various colors.
Researchers at North Carolina State University have developed a new type of nanoscale structure that resembles a “nano-shish-kebab,” consisting of multiple 2D nanosheets that appear to be impaled upon a 1D nanowire. However, the nanowire and nanosheets are actually a single, 3D structure consisting of a seamless series of germanium sulfide (GeS) crystals. The structure holds promise for use in the creation of new, 3D technologies.
Stretched-out clothing might not be a great practice for laundry day, but in the case of microprocessor manufacture, stretching out the atomic structure of the silicon in the critical components of a device can be a good way to increase a processor's performance.
Scientists from the U.S. Department of Energy’s National Renewable Energy Laboratory and other labs have demonstrated a process whereby quantum dots can self-assemble at the apex of a gallium arsenide-aluminum gallium arsenide core-shell nanowire interface. This activity at optimal locations in nanowires could improve solar cells, quantum computing, and lighting devices.
Researchers have tried for decades to replicate the effects of transistors in transition metal oxides by using a voltage to convert the material from an insulator to a metal, but the induced change only occurs within a few atomic layers of the surface. Recently, however, scientists in Japan have discovered that applying a voltage to a vanadium dioxide film several tens of nanometers thick converts the entire film from an insulator to a metal.
Organic semiconductors hold promise for making low-cost flexible electronics—if they can perform in spite of frequent flexing and sharp bending. Scientists have recently demonstrated extremely flexible organic semiconductors that withstood multiple bending cycles in which the devices were rolled to a radius as small as 200 μm. The scientists worked with numerous crystalline devices they made and found no degradation in their performance.
Silica microwires are the tiny and as-yet underutilized cousins of optical fibers. If precisely manufactured, however, these hair-like slivers of silica could enable applications and technology not currently possible with comparatively bulky optical fiber. By carefully controlling the shape of water droplets with an ultraviolet laser, a team of researchers from Australia and France has found a way to coax silica nanoparticles to self-assemble into much more highly uniform silica wires.
Existing optical beamsteering assemblies for technologies like LADAR, which scans a field of view with a laser to determine distance, are typically mechnical, bulky, slow, and inaccurate. In an effort to design a better, scalable technology, DARPA researchers have recently demonstrated the most complex optical phased array ever built onto a 2D chip.
High-performance infrared cameras are usual for night-vision goggles and are usually either active, which use invisible infrared sources, or passive, which detect thermal radiation without the need for illumination. Integrating both modes has proven challenging, but researchers at Northwestern University have done by using advanced type-II superlattice materials.
A Massachusetts Institute of Technology researcher has developed a technique that provides a new way of manipulating heat, allowing it to be controlled much as light waves can be manipulated by lenses and mirrors. The approach relies on engineered materials consisting of nanostructured semiconductor alloy crystals.
Silicon carbide crystals consist of a regular lattice formed by silicon and carbon atoms. At present, these semiconductors are extensively used in micro and opto-electronics. Physicists have recently modified silicon carbide crystals in a way that these exhibit new and surprising properties. This makes them interesting with regard to the design of high-performance computers or data transmission.
Investigators at the Virginia Tech Carilion Research Institute have invented a way to directly image biological structures at their most fundamental level and in their natural habitats. Their newly developed in situ molecular microscopy provides a gateway to imaging dynamic systems in structural biology