http://www.physorg.com/news117216813.html

Do you remember who employed Bob Lazar?  Office of Naval Intelligence.

Move over, silicon: Advances pave way for powerful carbon-based electronics

Bypassing decades-old conventions in making computer chips, Princeton
engineers developed a novel way to replace silicon with carbon on large
surfaces, clearing the way for new generations of faster, more powerful cell
phones, computers and other electronics.
The electronics industry has pushed the capabilities of silicon -- the
material at the heart of all computer chips -- to its limit, and one
intriguing replacement has been carbon, said Stephen Chou, professor of
electrical engineering. A material called graphene -- a single layer of
carbon atoms arranged in a honeycomb lattice -- could allow electronics to
process information and produce radio transmissions 10 times better than
silicon-based devices.

Until now, however, switching from silicon to carbon has not been possible
because technologists believed they needed graphene material in the same
form as the silicon used to make chips: a single crystal of material eight
or 12-inches wide. The largest single-crystal graphene sheets made to date
have been no wider than a couple millimeters, not big enough for a single
chip. Chou and researchers in his lab realized that a big graphene wafer is
not necessary, as long they could place small crystals of graphene only in
the active areas of the chip. They developed a novel method to achieve this
goal and demonstrated it by making high-performance working graphene
transistors.

"Our approach is to completely abandon the classical methods that industry
has been using for silicon integrated circuits," Chou said.

Chou, along with graduate student Xiaogan Liang and materials engineer
Zengli Fu, published their findings in the December 2007 issue of Nano
Letters. The research was funded in part by the Office of Naval Research.

In their new method, the researchers make a special stamp consisting of an
array of tiny flat-topped pillars, each one-tenth of a millimeter wide. They
press the pillars against a block of graphite (pure carbon), cutting thin
carbon sheets, which stick to the pillars. The stamp is then removed,
peeling away a few atomic layers of graphene. Finally, the stamp is aligned
with and pressed against a larger wafer, leaving the patches of graphene
precisely where transistors will be built.

The technique is like printing, Chou said. By repeating the process and
using variously shaped stamps (the researchers also made strips instead of
round pillars), all the active areas for transistors are covered with single
crystals of graphene.

"Previously, scientists have been able to peel graphene sheets from graphite
blocks, but they had no control over the size and location of the pieces
when placing them on a surface," Chou said.

One innovation that made the technique possible was to coat the stamp with a
special material that sticks to carbon when it is cold and releases when it
is warm, allowing the same stamp to pick up and release the graphene.

Chou's lab took the next step and built transistors -- tiny on-off
switches -- on their printed graphene crystals. Their transistors displayed
high performance; they were more than 10 times faster than silicon
transistors in moving "electronic holes" -- a key measure of speed.

The new technology could find almost immediate use in radio electronics,
such as cell phones and other wireless devices that require high power
output, Chou said. Depending on the level of interest from industry, the
technique could be applied to wireless communication devices

-- 

Ken

"Buddhism elucidates why we are sentient."
"Buddhism follows thought throughout the Universe."
"Karma means that you don't get away with anything."