Harvard University scientists have created nanowires with new useful properties. The wire not only absorbs light at specific wavelengths, but also light from other parts of the spectrum. The technology could have applications in areas ranging from consumer electronics to solar panels.
To create the nanowire, Bobby Day and Max Mankin, graduate students working in the lab of Charles Lieber, the Mark Hyman Jr. Professor of Chemistry, heated traditionally grown nanowires to just below their transformation point in a vacuum chamber. Silicon atoms, pumped into the chamber, then spontaneously crystallized on the wire.
Rather than form a uniform shell, the atoms grow into regularly spaced structures, similar to the droplets that appear when nanowires break down at high temperatures. Unlike with the droplets, though, the process can be tightly controlled.
“By varying the temperature and pressure, we can exert some control over the size and spacing of these structures,” Day said. “What we found was if we change the conditions, we can ‘tune’ how these structures are built.”
The wire cross-section can be adjusted to produce more rounded, square-type, or platelet-like shapes.
While Day and Mankin’s study focused on the wires’ ability to absorb different wavelengths of light, both said additional research is needed to explore other properties.
Also: Learn about Nanowire-Based Piezoelectric Power Generation.