Though the advantages promised by nanowires for electronics are vast, various manufacturing issues have kept them from leaping into our cell phones and DVD players. This isn't to say that other uses for the microscopic semiconductors haven't already found their way into reality.

Nanowires have already been used to create fanciful things like transparent active matrix displays as well as attempting more practical devices like cancer detectors. However, using them to create integrated circuits, one of the basic components of just about any modern electronic device, has been a bit of a bear.

A collaboration between Harvard University and the universities of Jena, Gottingen and Bremen in Germany has produced a fabrication technique for creating nanowire devices directly on silicon that is not only reproducible, but high-volume and low-cost. The group combined photolithography, the current de facto method for producing modern ICs, with spin-on glass technology to produce nanoscale ultraviolet light-emitting diodes.

"Because our fabrication technique is independent of the geometrical arrangement of the nanowires on the substrate, we envision further combining the process with one of the several methods already developed for the controlled placement and alignment of nanowires over large areas. We believe the marriage of these processes will soon provide the necessary control to enable integrated nanowire photonic circuits in a standard manufacturing setting," explained Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering of the School of Engineering and Applied Sciences at Harvard.

To create their device, the group sandwiched n-type zinc oxide nanowires between doped p-type silicon and a metallic contact, using spin-on glass as an insulator. The spin-on glass prevents contact between the silicon substrate and contact, allowing uniform current injection along the nanowires. With applied current, the nanowire devices function as LEDs. Emitted light can run the gamut from infrared to ultraviolet with the composition of the semiconductor nanowire determining the frequency of the radiation.

"Such an advance could lead to the development of a completely new class of integrated circuits, such as large arrays of ultra-small nanoscale lasers that could be designed as high-density optical interconnects or be used for on-chip chemical sensing," said Professor Carsten Ronning of the University of Jena.

The field of nanophotonics for use in computer systems is advancing quickly. IBM and Sun both boast optical interconnect technology in development. Certainly an efficient method for producing nanoscale LEDs and lasers would propel research forward at an even greater pace. Even though carbon nanotube-based technologies are exploding around the micro and nanoelectronics industries, there's no question that with the latest breakthroughs in nanophotonics, their heyday may be short-lived.