dimensional materials have an entire host of individual
houses because they may be just one atom thick. A*superstar researchers have
now advanced a way for growing large regions of atom-thin fabric to be used in
electronic gadgets [1].
Graphene, a unmarried layer of carbon atoms organized into a
honeycomb-like pattern, is the maximum well-known instance of a -dimensional
material. it's far more potent than metallic, has terrific electrical houses,
and will be used to make -dimensional gadgets which might be a lot smaller than
those currently crafted from bulk or skinny-movie silicon. however, it is not a
semiconductor. And so scientists are turning to different substances which have
this essential assets for growing transistors.
Shijie Wang from the A*big name Institute of materials
research and Engineering and his collaborators have now demonstrated a
technique for developing a unmarried atomic layer of molybdenum disulfide -- a
-dimensional semiconductor.
Molybdenum disulfide belongs to a circle of relatives of
substances known as transition-metal dichalcogenides. they have got two
chalcogenide atoms (which includes sulfur, selenium or tellurium) for every
transition-metal atom (molybdenum and tungsten are examples). those materials
and their extensive range of electrical residences offer an first-rate platform
material machine for flexible electronics. but creating extremely good cloth
over areas large enough for commercial-scale manufacturing is hard.
"traditional mechanical exfoliation techniques for
acquiring -dimensional substances have constrained usefulness in business
packages, and all preceding chemical techniques are incompatible for
integration with device fabrication," says Wang. "Our technique is a
one-step procedure that could develop appropriate-high-quality monolayer films,
or few layers of molybdenum disulfide films, at wafer scale on various
substrates the usage of magnetron sputtering."
The team fired a beam of argon ions at a molybdenum target
in a vacuum chamber. This ejected molybdenum atoms from the surface in which
they reacted with a nearby sulfur vapor. those atoms then assembled onto a
heated substrate of either sapphire or silicon. The group found that they could
grow monolayer, bilayer, trilayer or thicker samples by means of altering the
energy of the argon-ion beam or the deposition time.
They showed the exceptional in their fabric the use of some
of commonplace characterization equipment consisting of Raman spectroscopy,
atomic force microscopy, X-ray photoelectron spectroscopy and transmission
electron microscopy. The researchers also validated the brilliant electrical
residences in their molybdenum disulfide films through creating a running
transistor (see image).
"Our subsequent step in this work will focus on the
software of this approach to synthesize other -dimensional materials and
combine them with extraordinary materials for numerous tool applications,"
says Wang.
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