AT THE height of his career in 2001, Hendrik Sch枚n was producing papers at the remarkable rate of one every eight days. Physicists were spellbound by the speed and sheer number of breakthroughs coming from the young postdoc. He and his supervisor Bertram Batlogg at Lucent Technologies鈥� Bell Labs were even tipped to win a Nobel prize.
The Bell team seemed to have struck gold by producing tiny organic crystals that behaved like semiconductors, the key ingredient of computer chips. Scaling down the size of transistors to squeeze more electronic components onto a chip has allowed computers to double in speed every 18 months. Many fear current technologies can鈥檛 possibly shrink transistors much further, but the team鈥檚 approach promised to come to the rescue.
Colleague Christian Kloc grew extremely pure crystals of pentacene, molecules consisting of five adjacent rings of carbon atoms. By attaching gold electrodes to the tiny crystals and covering them with a layer of aluminium oxide, Sch枚n turned them into organic transistors.
Advertisement
Discoveries followed thick and fast. Last December, Sch枚n and colleagues Hong Meng and Zhenan Bao built a transistor from a single layer of organic molecules just 0.1 nanometres thick. Sch枚n and colleagues also made lasers and solar cells from pentacene. They even showed that pentacene, as well as the related molecules anthracene and tetracene, could superconduct.
In 2000, Sch枚n and colleagues claimed to have built the first electrically powered organic laser from a tetracene crystal. Organic lasers would be much cheaper than their inorganic counterparts found in CD players and telecommunications networks. The only organic lasers produced previously needed a conventional laser to power them, but Sch枚n鈥檚 crystal produced intense yellow-green light in response to electric current.
Physicists were also enthralled by Sch枚n, Kloc and Batlogg鈥檚 discovery that under the right conditions, the football-shaped carbon molecules known as buckyballs superconduct at far higher temperatures than previously thought. All these reports of breakthroughs must now be scrapped because the experiments on which they are based were run by Sch枚n alone. The case is bound to do untold damage to the reputation of the field in the eyes of investors but scientists insist that their goals are still achievable. 鈥淪omeone will eventually produce a single-molecule transistor,鈥� says Richard Jones, head of the physics department at Sheffield University.
Others say Sch枚n inspired them to try experiments they would otherwise never have dreamed of. 鈥淚f Sch枚n, Batlogg and Kloc hadn鈥檛 come along, no one would have thought of making devices from single crystals,鈥� says Arthur Ramirez of Los Alamos National Laboratory, who has made switches from pentacene crystals. 鈥淭heir work has opened the door.鈥�
But for researchers trying to repeat Sch枚n鈥檚 superconductivity results, the past few years have been wasted, according to Paul McEuen of Cornell University, one of the first people to spot the danger signs in Sch枚n鈥檚 papers. 鈥淭here鈥檚 a lot of lost effort by people and that鈥檚 one of the tragedies, especially for students and postdocs.鈥�