By Peter Weiss
In a feat of nanometer-scale engineering, researchers have produced semiconductor filaments that are as thin as viruses but contain working electronic and optical devices. Alternating bands of different semiconductor materials in the superthin wires serve as the electron and photon manipulators. Someday, such striped strands may form the basis of a new type of circuitry that is far tinier, faster, and more energy efficient than conventional chips will ever be, the scientists say.
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Last year, a Harvard University team led by Charles M. Lieber demonstrated nanowire-based electronic devices and rudimentary logic circuits, but those were composed of wires of uniform composition (SN: 11/10/01, p. 294: Available to subscribers at Wiring teensy tubes, strands into circuits). By crossing different nanowires over one another, the researchers made them behave as transistors and diodes.