Researchers at the Cambridge-based Massachusetts Institute of Technology (MIT) announce the development of a new technique that allows them to pattern semiconductor nanocrystal films at nanoscale (billionths of a meter) resolution.
This type of nanocrystals are heralded as an important new material for a wide array of applications, ranging from developing advanced photonic circuits and building new biomolecular detectors to creating novel types of pixels for high-resolution displays.
In addition, the material may also be used to create a new class of highly efficient solar cells. But the main challenge facing the efforts to bring all these applications to the market is that nanocrystal films could not be fashioned in a consistent manner.
Until now, all films had tiny cracks on their surface, which made it very difficult for researchers to measure their properties, and use them in practice. It is important to remember that the size of a semiconductor nanocrystal determines both its electrical and optical properties.
With the new nanoscale-resolution patterning technique, it is possible to construct semiconductor nanocrystal films according to specifications. As evidenced by the image to the left, experts were able to inscribe the MIT logo on a surface using the method.
The investigation was made possible with the support of the US Department of Energy (DOE), the US Army Research Office, and Samsung. Details of the investigation appear in the latest online issue of the esteemed scientific journal Nano Letters.
“The challenge in the past has been achieving thin, uniform films, patterned at high resolution, with good contact between the nanocrystals and no cracking. [The new method,] while deceptively simple in appearance, accomplishes all of these objectives,” says Douglas Natelson.
The expert, who holds an appointment as a professor of physics and astronomy at the Rice University, was not a part of the new investigation. “I think this is a very nice achievement,” he goes on to say .
“The fluorescence images showing the nanopatterned films are eye-popping, particularly for those who know how tough this is,” Natelson explains.
“Though the nanoscale patterns are below the resolution limit of the optical microscope, the nanocrystals act as a light source, rendering them visible,” Mentzel says.