under comparable conditions. Solasta’s configuration might actually be working. And better efficiency was coming soon. the silicon in most solar cells contains additives, called dopants, usually boron and phosphorus, that dramatically increase voltage, the force that makes electrical currents flow. Solasta’s best sample, the 0.25 percent cell, was a primitive device using undoped silicon, but the postdocs Ying Xu and Yantao Gao, with long experience of doping, were ready to start this process as soon as Middlesex Gases delivered the necessary ingredients—any day now, in other words. Thus, a meeting in mid-August 2007 had, on the whole, a cheery feel—on the whole, but not completely. CEO Clary warned that, at the current burn rate, funds would run out this time next year—a nightmarish prospect for the physicists, who, having barely gotten into the Nonantum lab, saw their progress in six weeks as near-miraculous. Bill Joy took a more optimistic tack. “Let’s say by Christmas we have 7 or 8 percent,” he said, “and a road map to get to 12 and 24 percent. We’d have a story we could use to raise the money to move faster, by hiring more people.” The sooner they started the money hunt, the better, he said: “You’ve got ethanol companies trying to borrow $100 million to start manufacturing facilities, and they can’t. Six months ago, they could have. Solar is hot now, but it could change, like ethanol.” On the other hand, he added, solar didn’t seem as likely to fade. With Germany aiming for a solar panel on every roof, and interest growing in China and India, unmet demand might be near-infinite. Joy, at 53, sounded like someone who knew whereof he spoke. He even had the look of an eccentric genius, pale and tall and very thin, with mussed hair and several days’ growth of beard. doping began in early september. “our growers,” said Kempa, meaning the postdocs and Rybczynski, “are frantically working. We had to slow them down. They stay over the weekend, they don’t sleep—a typical immigrant attitude.” By a mid-October meeting, the best nanocoax solar cell, the “champion,” was getting almost 2 percent efficiency. Dopant concentrations and silicon thickness hadn’t even been optimized yet, so further gains couldn’t be far behind. Still, management wasn’t celebrating; in fact, the people from KP seemed distracted. In August, Joy had talked about a target of 8 percent by Christmas; now he was talking about getting to 15 percent by Christmas—an efficiency Solasta would never actually achieve and wouldn’t even approach for two more years. Clary was still fretting about the money clock, having moved his estimated cash zero date up a couple of months, to June 2008. During the meeting, Ren and 20
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Kempa needled the CEO. Whenever Clary made a technical suggestion or asked them to update him on an aspect of their work, they said, Oh, no, we can’t do that; that’s research! The tone was kept light and jokey, but they seemed to be reacting to Clary’s concern that the physicists hadn’t yet made the pivot from a scientific mindset to an engineering one, from what can we learn? to how do we get to 15 percent? Back in February, Joy had exhorted the team to “learn to fail faster.” It was a fashionable piece of business advice, but in context it meant abandoning ideas that didn’t deliver fast results, even if the physicists believed they would prove out in the end. Thus, an early collaboration between Solasta and a Spanish university team that had proposed to deposit silicon on Solasta’s nanotubes using a cheap, fast “wet chemistry” process was terminated after initial samples from the Spaniards were found to have short circuits. Similarly, at the October meeting, Clary vetoed the idea of trying a new metal—instead of aluminum, tin—for one of the conductors. Ying Xu thought tin would sputter faster while conducting as well as aluminum, but Clary didn’t see the possible gain as being worth the time or potential complications. Conflicts between business motives and scientific ones— between “what can we learn?” and “how can we get to 15 percent?”—would recur at Solasta. Such disputes always flare up when companies ask scientists to turn new technologies into products, says the New York University philosopher of science Michael Strevens. “Scientists are interested in the value of the knowledge they contribute for all time,” he says. “It’s quite natural that a company will want technologies to move quickly to commercial viability, whereas scientists aren’t all that interested in that. . . . Even if the product doesn’t go anywhere, the scientist still gets credit for the ideas behind it.” Reflecting on this disconnect as it played out at Solasta, Naughton says, “We [scientists] never lacked for ideas. Maybe the company wasn’t the right forum for trying new ideas, but I’d rather have too many ideas than too few.” “Kris Kempa was worried,” Clary says, “about publishing papers. That doesn’t win over investors. What wins over investors is efficiency numbers.” while 15 percent efficiency remained elusive, the team came most of the way to 8 percent by March 2008. The actual number was 5.7 percent, and they had gotten there thanks to a radical design change suggested by Kempa, who had put it through computer simulation trials. In the old configuration, the nanocoax was joined to a nano-antenna. In the new, the nanocoax doubled as a nanoantenna. Crucially, in the new design, indium tin oxide (ITO) replaced aluminum as the top metal layer. Electrically conductive but also transparent, ITO, like the metallic grid atop