Sentences with phrase «gallium arsenide»

Meanwhile, multi-junction concentrator solar cells made with thin films of gallium arsenide have achieved efficiencies of around 40 percent (although they're pricey — they were developed to power satellites).

Not only are the chips biodegradable, but using wood cuts out the need for petroleum - based materials as well as gallium arsenide, a toxic material that is used in the chips of the majority of today's wireless devices.

The solar cell is made from the semiconductor gallium arsenide and then stamped directly on a flexible metal substrate without using an adhesive, which would have added thickness.

Some advanced solar cells use gallium arsenide; gallium is quite a rare element and arsenic is highly toxic — the ultimate disposal of panels composed of such materials would need to be done responsibly.

The Joint Center for Artificial Photosynthesis, a federally funded lab based at the California Institute of Technology in Pasadena, said it has figured out how to use materials such as silicon and gallium arsenide in a process to split water into hydrogen and oxygen using sunlight.

Yamauchi H, Takahashi K, Mashiko M, Yamamura Y. Biological monitoring of arsenic exposure of gallium arsenide - and inorganic arsenic - exposed workers by determination of inorganic arsenic and its metabolites in urine and hair.

This new design iS the first time gallium arsenide would be used as a cryogenic scintillation detector.

Researchers at the US Department of Energy's Lawrence Berkeley National Laboratory, however, have proposed building a new dark matter experiment using an ultrasensitive detector that incorporates crystals of gallium arsenide (GaAs), along with silicon and boron.

A team of scientists from ETH Zurich in Switzerland and the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) in Hamburg have, for the first time, unraveled the electronic dynamical processes that occur upon excitation of electrons in gallium arsenide at the attosecond timescale.

But over the years, as Willett improved his circuit design to incite more of the alleged non-abelian anyons to form and his collaborators increased the purity of the gallium arsenide crystals, the controllable interference signal grew clearer.

The coating is a nickel oxide film that prevents rusts building - up on the semiconductor electrodes (silicon or gallium arsenide), while also acting as a highly reactive catalysis.

The product of decades of trial and error by Willett and his collaborators, it was made from a flake of gallium arsenide so pure, he said, that electrons inside could sense one another's presence across vast micrometers of distance.

Semiconductors (such as silicon or gallium arsenide): used in solar panels to efficiently absorb light.

The lab used the light to probe the shift in an ultra-high quality, two - dimensional electron gas supplied by Purdue University physicist Michael Manfra and set in a gallium arsenide quantum well (to contain the particles) under the influence of a strong magnetic field and low temperature.

In this case, the levels are those of two - dimensional electrons in solid gallium arsenide in a strong perpendicular magnetic field.

The researchers used quantum dots created from an indium arsenide and gallium arsenide platform, producing pure single photons and entangled photons.

But it's possible to use indium arsenide, gallium arsenide, gallium nitride or other so - called III - V materials from group III and group V. Being from different groups on the periodic table means transistor materials would have different properties, and the big one here is better electron mobility.

The rapidly expanding field of optoelectronics has until now had to rely on a more complex and much more expensive semiconductor, gallium arsenide.

Semiconductors such as silicon and gallium arsenide have a «bandgap» between the «valence band» — the energy levels where electrons normally reside — and the higher - energy «conduction band» in which electrons are free to move.

In gallium arsenide the electrons drop directly across the bandgap to recombine with the holes they had earlier left behind.

Now physicists at ETH Zurich for the first time resolved the response of electrons in gallium arsenide at the attosecond (10 - 18 s) timescale, and gained unexpected insights for future ultrafast opto - electronic devices with operation frequencies in the petahertz regime.

Gallium arsenide is a technologically important narrow - band - gap semiconductor, in which the excitation of electrons from the valence into the conduction band produces charge carriers that can transport electrical current through electronics components.

The specifics: a germanium wafer is spun at high speeds and subjected to various gases that encourage the growth of layers of semiconducting material such as gallium arsenide.

Made from aluminium gallium arsenide, the nanocrystals are 500 times narrower than a human hair and can be applied to ordinary glass as ultra-thin, lightweight films.

Standard LEDs are made of compounds containing gallium arsenide, which emit strongly in the infrared, red, yellow and green.

An important application is in the compound gallium arsenide, used as a semiconductor, most notably in light - emitting diodes (LEDs).

To concentrate the energy of laser light to an even finer area, the team patterned aluminum dots of various sizes, from tens of micrometers down to 30 nanometers, across the surface of silicon, silicon germanium alloy, gallium arsenide, gallium nitride, and sapphire.

However, electrons in gallium arsenide do not have enough energy to emit in the shorter blue wavelengths, so other materials must be used.

The base contains gallium arsenide; the post, aluminum gallium arsenide; and the 200 - nanometer - thick microdisk cap, quantum dots of indium arsenide embedded in gallium arsenide.

Two examples: graphene — single - atom - thick sheets of carbon atoms — has unique mechanical, electrical, and optical properties; and two - dimensional electron gases (2DEG)-- planar collections of electrons supported at the interface between certain semiconductors such as gallium arsenide — allow the observation of such emergent behaviors as the quantum Hall effect and the spin Hall effect.

Some of the waveguides feature an optically active material, such as an indium gallium arsenide semiconductor, that can amplify or absorb signal light depending on whether or not it is optically excited.

A simple dipole antenna fabricated on semi-insulating gallium arsenide will only radiate 2 per cent of its power into the air.

The sample that the researchers use is made on a substrate of gallium arsenide (GaAs) and contains two important parts.

Brown and Parker are now working on making the photonic crystal out of silicon, gallium arsenide or indium phosphide, which would allow them to integrate the antenna and electronics on the same chip.

Scientists have tried building the electrodes out of common semiconductors such as silicon or gallium arsenide — which absorb light and are also used in solar panels — but a major problem is that these materials develop an oxide layer (that is, rust) when exposed to water.

Using this process, the researchers grew stacks of flexible electronics up to three layers high, mixed and matched from silicon, the semiconductors gallium arsenide and gallium nitride, as well as carbon nanotubes, they reported in Science.

Meanwhile, other researchers report that their latest cells are as efficient as standard silicon cells and may soon rival costly gallium arsenide cells.

Hoffman and his colleagues crafted their metamaterial semiconductor by placing alternating 80 - nanometer - thick (one nanometer equals 3.94 x 10 - 8 inch) layers of indium gallium arsenide and indium aluminum arsenide atop an indium phosphide substrate 5.1 centimeters (two inches) in diameter.

Physicist Tony Kent and his colleagues at the University of Nottingham in England managed to create such an amplifier from a thin, layered lattice made of two semiconductors, gallium arsenide and aluminum arsenide.

Similar trends can be expected for other materials with a higher electronic band gap like gallium arsenide or metal - halide perovskites.

Ashoori and his colleagues employed tunneling to probe a two - dimensional sheet of gallium arsenide.

Ordinarily in such a system, electrons in gallium arsenide are repelled by aluminum gallium arsenide, and would not go through the barrier layer.

Diodes are composed of two conductive materials, such as silicon or germanium; the light - emitting variety uses materials such as gallium arsenide, which releases photons when electricity flows through it.

The researchers applied electrical pulses to eject electrons from the first layer of gallium arsenide and into the second layer.

They reasoned that those electrons that were able to tunnel through to the second layer of gallium arsenide did so because their momenta and energies coincided with those of electronic states in that layer.

This is the case for electrons in gallium arsenide, and the resulting distribution has the shape of a parabola.

In other words, the momentum and energy of the electrons tunneling into gallium arsenide were the same as those of the electrons residing within the material.

To do this, they first had to resolve silicon crystal lattice defects to a point where the cavities were essentially equivalent to those grown on lattice - matched gallium arsenide (GaAs) substrates.

In their device, lead sulfide quantum dots replace semiconductor materials such as silicon and copper indium gallium arsenide.

«We have discovered that by inserting a very thin film of gallium arsenide into the connecting junction of stacked cells we can virtually eliminate voltage loss without blocking any of the solar energy,» says Dr. Salah Bedair, a professor of electrical engineering at NC State and senior author of a paper describing the work.