Graphene versus Carbon Nanotubes: Which will be applied to commercial electronics first?

Some 17 years ago, when carbon nanotubes (CNTs) were first discovered, physicists and material scientists were fascinated with this new form of carbon that forever changed the paradigm of the three basic forms of carbon: diamond, graphite and amorphous carbon.

Since then a lot of hope and a lot of research has been devoted to exploiting some of some CNTs beneficial characteristics to electronics applications, namely their charged-carrier mobility.

But working with CNTs has always been hampered by the intrinsic difficulty in putting them where you want them and connecting them.

While research continued in earnest on CNTs, a hypothetical material called graphene''single, one-atom thick, sheets of graphite''was gaining more attention. Graphene had only been postulated about until 2004 when researchers at the University of Manchester in the UK produced some of the material.

A new star was born. The world of solid-state physics was enamored with a new ''wonder'' material that displayed many of the positive characteristics of CNTs in electronic applications, but was easier to interconnect and could follow relatively simple chemical doping techniques.

Unlike CNTs, which require a different set of processing techniques from silicon, graphene shared the same set of processing techniques currently used for silicon. The difference being that silicon becomes pretty useless at the nanometer scale.

In just a few short years, graphene has begun to show some research results within the last few months, with a number of research groups announcing some positive results for graphene in electronics applications, not the least of which being IBM

and the University of Manchester researchers touting the ''smallest transistor ever made''.

But there are some big questions remaining about graphene, including it doesn''t have brilliant intrinsic switching properties''you can change it slightly but you can''t seem to turn it completely off'so far. And the deposition of stable graphene thin-films is still pretty tricky.

Whether these problems will be easier to surmount than the problems that have plagued CNTs remains to be seen. But it appears that for now the new darling of the nanomaterial world is graphene.


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