Electrical wires three atoms wide have been assembled using diamondoids, which are specks of diamond found naturally in petroleum fluids.

Researchers from Stanford University and the U.S. Department of Energy’s SLAC National Accelerator Laboratory theorize that these conductive nanowires could be applied in fabrics that generate electricity, optoelectronic devices that use both electricity and light, and superconducting materials that conduct electricity without loss.

Molecular building blocks join the tip of a growing nanowire. Molecular building blocks join the tip of a growing nanowire. The self-assembling needle-like wires use a combination of copper and sulfur known as a chalcogenide as a semiconducting core surrounded by the attached diamondoids, which form an insulating shell. Diamondoids are interlocking cages of carbon and hydrogen that are attracted to each other through what are known as van der Waals forces.

Beginning with the smallest possible diamondoids – single cages that contain just 10 carbon atoms – the scientists attached a sulfur atom to each. Each sulfur atom bonded with a single copper ion while floating in a solution, forming the basic nanowire building block. These components then drifted toward each other, drawn by the van der Waals attraction between the diamondoids, and attached to the growing tip of the nanowire.

One-dimensional nanowires based on cadmium, zinc, iron, and silver have been fabricated, including some that grew long enough to see without a microscope. The cadmium-based wires are similar to materials used in optoelectronics, such as light-emitting diodes, and the zinc-based ones are like those used in solar applications and in piezoelectric energy generators, which convert motion into electricity.

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