In one of those happy research accidents that lead to new breakthroughs, scientists at the National Institute of Standards and Technology (NIST) have developed a new kind of nanowire that produces light, much like the glow produced by LED technology. The team was actually fine tuning a new method for manufacturing ultra thin or nanoscale wires, hoping to create a process that yields a product with uniform traits, when their experiment began to light up.
The Trouble with Nanowires
Typically, nanowires are grown on a base material or substrate. The process involves depositing molecules such as zinc oxide in the form of a gas. The nanowires then “grow” vertically, like bristles on a brush. The problem is, they grow so densely that it is difficult to pick out the ones with better characteristics. Also, since the wires only touch the substrate at one end, their properties are not uniformly distributed.
A New Method of Growing Nanowires That Glow
The NIST team came up with a solution, which is to grow the nanowires horizontally. They converted gold into nanoparticles by superheating it, then manipulated zinc oxide nanocrystals into pushing the gold particles along the substrate, forming nanowires. Because the wire touches the substrate at all points, its characteristcs are more uniformly influenced than in the vertical growth method. When the researchers increased the size of the gold particle, the wires grew a fin-like nanowall which allowed electrons to flow, giving off a light similar to that of an LED.
Glowing Nanowires vs. LEDs
The NIST researchers envision uses for the new light-emitting nanowires in chip-sized “laboratories” and other miniature devices for specialized purposes. Though large-scale applications are a possibility, that seems pretty remote at the present, leaving LEDs in the lead for now in terms of providing an energy saving solution to lighting needs. LEDs are already lending themselves to large scale applications in street lighting and parking garages, for example, and new research is yielding more powerful LEDs, as well as new technologies for boosting the efficiency and lifespan of LED fixtures.
Image (altered): Nanowires courtesy of NIST.
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.