梦想照进现实：石墨烯商业前景狂想曲

    合成薄膜石墨烯所需要的成本和时间要显著高于生产屑状石墨烯。后者通常是通过一个“又快又脏”的程序，把块状石墨分解成几百万个小片，而大片的石墨烯薄膜则是小心地“种”在铜、锗或金刚砂材质的基板上。

    薄膜状石墨烯的产量也非常有限。默腾斯说：“现在有几千家小公司都可以生产石墨烯，但是价格非常昂贵，而且产量很低。”他还指出，一片直径1英寸的石墨烯圆片的价格就高达100美元左右。

    卡耐基梅隆大学（ Carnegie Mellon University）电子与计算机工程学教授伊莱亚斯•托维指出，用石墨烯生产晶体管的另一个障碍是，石墨烯不具备所谓的“带隙”。这是一种非常重要的性能，它使晶体管能够“开”和“关”，而且在“关”的状态下不会泄漏电荷。

    珍妮•刘也说：“带隙工艺一直是阻碍用石墨烯研制晶体管和电脑芯片的最大挑战。”

    帕特森称：要克服带隙问题，就要求对这种材料的控制必须达到原子层面，而“这可以说是在推动现有技术的边缘。10年内，我们将看到这些问题逐步得到解决。”

很大程度上只是时间问题

    托维指出，如果石墨烯要想成为硅的补充产品，它的成功将取决于成本和性能。

    “硅的基础生产工艺是建立在几十亿美元的投资基础上的，因此很难被完全取代。石墨烯要想取代硅，不仅要具备卓越的性能，还要具备极低的价格，才能促使整个行业改变方向。”

    硅用于生产晶体管的历史可以追溯到上世纪50年代，相比之下，石墨烯只有10年的历史，但是石墨烯已经取得了显著的进步。比如8年前，最大的石墨烯薄膜还是在实验室中用手工做出来的，宽度还比不上人类的一根头发丝。而诚如珍妮•刘所言：“现在，新型的卷对卷印刷工艺使100米长的石墨烯薄膜已经成为现实。”

    珍妮•刘补充说：“随着行业对石墨烯技术的兴趣、投资和研究力度日益加大，我认为石墨烯行业形成规模经济，生产出真正低成本、量产级的高质量石墨烯只是一个时间问题。”

    曼彻斯特大学的维加亚拉哈万说：“石墨烯的其它障碍可以用时间和努力来克服。我们每天都在学习新东西，目前我们还有很多不懂的东西，而且还有很多研究要做。”比如研究人员现在才刚刚开始研究石墨烯对环境的污染后果以及对人体健康的影响。

    但是，石墨烯或许足以颠覆市值达2万亿美元的电子行业，这个前景仍然不容忽视。

    比如帕特森就畅想道：“我们不妨想象一下，一枚只有普通邮票十分之一大小的芯片，医生却可以用它来检测各种东西。到时候，大家不用每次都抽三管血来检查两个指标，然后第二天再来取结果。而是只需要一滴血，就可以检测几百种指标，然后马上获得结果。石墨烯可以让这种想法成为现实。”（财富中文网）

    译者：朴成奎

    Synthesizing graphene in sheet form is considerably more expensive and time-consuming than producing graphene flakes. Whereas the latter typically involves a "quick and dirty" process by which bulk graphite is disassembled into millions of tiny pieces, Lau explained, large sheets of graphene are carefully "grown" on substrates such as copper, germanium, or silicon carbide.

    Graphene sheets are also prone to defects and "very difficult to make in good quality," Ron Mertens, owner and editor of Graphene-Info.com, said.

    Production capacity is also very limited. "There are thousands of small companies that can make graphene, but it's expensive and low-capacity," Mertens said. A round wafer measuring one inch in diameter, for instance, costs about $100, he added.

    An even thornier obstacle on the way to graphene transistors is the fact that the material has no "band gap," an essential property that allows transistors to be turned on and off without leaking electronic charge in the "off" state, said Elias Towe, a professor of electrical and computer engineering at Carnegie Mellon University.

    "Band-gap engineering has been and remains the biggest challenge in the development of graphene transistors and computer chips," Lau said.

    It requires controlling the material almost down at the atomic level, and "that's really pushing the edges of existing technology," Patterson said. "In 10 years, we'll start to see these problems be solved."

'It is largely a matter of time'

    If graphene is to succeed as a replacement for silicon, every unit of cost and performance will make a difference, Towe said.

    "Silicon is hard to displace, with all the billions dollars of investments made in manufacturing infrastructure," he said. "A replacement for silicon has to offer extraordinary performance at extremely rock-bottom cost to compel industry to change its way."

    Though graphene is just 10 years old -- in contrast, use of silicon in transistors dates to the early 1950s -- considerable progress has already been made. For example, the largest graphene sheet was produced by hand in a laboratory eight years ago; its width was less than that of a human hair. "Nowadays, roll-to-roll printing of graphene sheets up to 100 meters long has been achieved," Lau said.

    "With the increasing interest, investment, and research in graphene-based technology, I think it is largely a matter of time before the economy of scale kicks in and truly low-cost, large-scale production of high-quality graphene is accomplished," she added.

    The next series of hurdles "can be overcome with time and effort," said Vijayaraghavan of the University of Manchester. "We're learning new things every day. There is still much we don't understand, and still plenty of research to be done." For example, researchers have only just begun to study the consequences of graphene pollution on the environment and human health.

    Still, the possibilities that graphene holds for the nearly $2 trillion global electronics industry are difficult to ignore.

    "Imagine a tiny chip, one-tenth the size of a postage stamp, that your doctor could use to test for all kinds of things," Patterson said. "You'd walk in, and instead of having to give three vials of blood to test for two things and then get the results the next day, your doctor could use one drop of blood to test for hundreds of things and you'd get the results right away. Graphene makes it possible."