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Graphene doped with various gaseous species (both acceptors and donors) can be returned to an undoped state by gentle heating in vacuum. [22] [24] Even for dopant concentrations in excess of 10 12 cm −2 carrier mobility exhibits no observable change. [24] Graphene doped with potassium in ultra-high vacuum at low temperature can reduce ...
In addition, it is known that when single-layer graphene is supported on an amorphous material, the thermal conductivity is reduced to about 500 – 600 W⋅m −1 ⋅K −1 at room temperature as a result of scattering of graphene lattice waves by the substrate, [172] [173] and can be even lower for few-layer graphene encased in amorphous ...
Graphene is an atomic-scale honeycomb lattice made of carbon atoms. Graphene is a one-atom thick sheet of graphite, with atoms arranged in a regular hexagonal pattern, [51] [52] also called "nanocomposite paper". [53] Graphene has a theoretical specific surface area of 2630 m 2 /g which can theoretically lead to a capacitance of 550 F/g. In ...
The molecule absorption introduces a local change in electrical resistance of graphene sensors. While this effect occurs in other materials, graphene is superior due to its high electrical conductivity (even when few carriers are present) and low noise, which makes this change in resistance detectable. [153]
A rapidly increasing list of graphene production techniques have been developed to enable graphene's use in commercial applications. [1]Isolated 2D crystals cannot be grown via chemical synthesis beyond small sizes even in principle, because the rapid growth of phonon density with increasing lateral size forces 2D crystallites to bend into the third dimension. [2]
[11] [21] Most integer quantum Hall experiments are now performed on gallium arsenide heterostructures, although many other semiconductor materials can be used. In 2007, the integer quantum Hall effect was reported in graphene at temperatures as high as room temperature, [22] and in the magnesium zinc oxide ZnO–Mg x Zn 1−x O. [23]
Even if the material's resistivity is known, calculating the resistance of something made from it may, in some cases, be much more complicated than the formula = / above. One example is spreading resistance profiling , where the material is inhomogeneous (different resistivity in different places), and the exact paths of current flow are not ...
In 2015, researchers in China used porous graphene as the material for a lithium-ion battery anode in order to increase the specific capacity and binding energy between lithium atoms at the anode. The properties of the battery can be tuned by applying strain. The binding energy increases as biaxial strain is applied. [24]