Can any electronics material rival silicon—tunable, current-carrying, self-insulating, easy to fabricate, as common as sand on the beach? Even if another rival came forward, could it ever overcome silicon’s 50-year, trillion-dollar head start in development?
Yet we do need an adjunct to silicon, because so much of the potential market for electronics has yet to be opened. Electronics in paper, on walls, and in clothing are today mere novelties, simply because silicon can’t easily be painted on a surface, draped on a flexible platform, or used to cover large areas. What’s needed is something that can do all that and still be churned out cheaply and in bulk, processed easily, and slipped deftly into the guts of the next generations of electronics.
Allow us to suggest a candidate: graphene, an atom-thick sheet of carbon linked in a hexagonal network, like chicken wire. The material isn’t so much a replacement for silicon as a complement to it, serving many purposes where silicon is inadequate and mixing with silicon in the fabrication of certain devices. Graphene was discovered in the 1970s but first properly appreciated only in 2004, when Andre Geim and Konstantin Novoselov, Russian-born researchers at the University of Manchester, in England, managed to transfer it to a substrate and study its unique attributes. That work has won them the 2010 Nobel Prize in Physics.
Of course, any new form of pure carbon would be big news, but graphene’s properties are remarkable. As thin in one of its dimensions as a material can get, it is nevertheless impermeable to gas and is the strongest two-dimensional material ever tested, with a tensile strength 200 times as great as that of steel. What’s more, it conducts heat better than any metal. Best of all—to readers of this magazine—are graphene’s unusual electrical characteristics, especially its ability to carry charge carriers at speeds dwarfing those possible in silicon. That ability could allow for superfast switching in data processing.
Silicon has seen many a contender in the past—for instance, germanium, the material used for the very first transistor, and gallium arsenide, which for all its usefulness remains a mere niche material. So why do we nurse such high hopes for this rarefied form of carbon?
First, recall that carbon stands just above silicon in the periodic table, and hence shares many of silicon’s inherent properties. Second, consider that researchers around the world are rapidly accumulating new knowledge of graphene’s fantastic properties and getting better by the month at manufacturing it in bulk. Finally, keep in mind that the semiconductor manufacturing industry is under increasing stress to keep pace with Moore’s Law, and therefore more likely to consider new materials.
So the question really isn’t “Why graphene now?” but rather: “Why didn’t the electronics industry start with graphene in the first place?”