Comment Re:practical? (Score 2, Informative) 83
In fact that's the beautiful, and arguably the most perplexing, thing abbout graphene. Charge carriers travel thousands of interatomic distances without scattering, even when under 'dirty' conditions. Adsorbates, proximal substrates, lattice vibrations, none of these seems to phase the carriers in their passage from one place to another. This is truly astounding, and we really don't yet know why. But it does suggest that this is one less big thing to worry about when it comes to making devices.
Moreover, graphene is structurally robust, even down to an atom thick and sub-10-nm wide. It doesn't fall apart, it doesn't aggregate, it doesn't oxidize --- it's just happy to be what it is. This is not as astounding as the ballistic nature of it's carriers --- the carbon-carbon bond in graphene/graphite is one of the strongest known, stronger even than the carbon-carbon bond of diamond! Nonetheless, even the most naively optimistic researchers find this pretty amazing.
Of course, there are *lots* of other big things to worry about, it's just that material and electronic stability aren't among them.
As per making a ballistic field-effect transistor (a la a carbon nanotube FET), this has already been done, and the characteristics are rubbish! And there's no way around this. Conventional device structures in graphene leak like sieves, which seems to be fundamental rather than a consequence of fabrication issues. Which is why the SET result is so encouraging. The characteristics are still not fabulous, or at least not yet, but it's likely that this could be the only way to make a transistor with useful ON-OFF behaviour.
Oh, and CNTs are never going to be a goer for consumer electronics, imho. Their properties are just too dependent on their chirality (which determines even whether they are semiconducting or metallic), and there is still no good way of addressing this. Graphene doesn't suffer from this problem, the properties of one sheet are the same as those of any other sheet. Rotational alignment and edge structure could causes problems at the dimensions people are talking about for future single electron devices. But at least you don't have the problem of not knowing if you've even got a metal or a semiconductor, as you do with nanotubes.
But then of course, there are all those unseen issues to come. But that's the wonderful thing about emerging fields of research, you get to wax lyrical about all the great possibilities that could be without all those bothersome reality-induced pitfalls that always arise. We're still in the honeymoon period of graphene research. How long the actual marriage will last is anyone's guess.
Moreover, graphene is structurally robust, even down to an atom thick and sub-10-nm wide. It doesn't fall apart, it doesn't aggregate, it doesn't oxidize --- it's just happy to be what it is. This is not as astounding as the ballistic nature of it's carriers --- the carbon-carbon bond in graphene/graphite is one of the strongest known, stronger even than the carbon-carbon bond of diamond! Nonetheless, even the most naively optimistic researchers find this pretty amazing.
Of course, there are *lots* of other big things to worry about, it's just that material and electronic stability aren't among them.
As per making a ballistic field-effect transistor (a la a carbon nanotube FET), this has already been done, and the characteristics are rubbish! And there's no way around this. Conventional device structures in graphene leak like sieves, which seems to be fundamental rather than a consequence of fabrication issues. Which is why the SET result is so encouraging. The characteristics are still not fabulous, or at least not yet, but it's likely that this could be the only way to make a transistor with useful ON-OFF behaviour.
Oh, and CNTs are never going to be a goer for consumer electronics, imho. Their properties are just too dependent on their chirality (which determines even whether they are semiconducting or metallic), and there is still no good way of addressing this. Graphene doesn't suffer from this problem, the properties of one sheet are the same as those of any other sheet. Rotational alignment and edge structure could causes problems at the dimensions people are talking about for future single electron devices. But at least you don't have the problem of not knowing if you've even got a metal or a semiconductor, as you do with nanotubes.
But then of course, there are all those unseen issues to come. But that's the wonderful thing about emerging fields of research, you get to wax lyrical about all the great possibilities that could be without all those bothersome reality-induced pitfalls that always arise. We're still in the honeymoon period of graphene research. How long the actual marriage will last is anyone's guess.
