Researchers at North Carolina State University have developed a new type of nanoscale structure that resembles a "nano-shish-kebab," consisting of multiple two-dimensional nanosheets that appear to be impaled upon a one-dimensional nanowire. But looks can be deceiving, as the nanowire and nanosheets are actually a single, three-dimensional structure consisting of a single, seamless series of germanium sulfide (GeS) crystals. The structure holds promise for use in the creation of new, three-dimensional (3-D) technologies.
The researchers believe this is the first engineered nanomaterial to combine one-dimensional and two-dimensional structures in which all of the components have a shared crystalline structure.
Combining the nanowire and nanosheets into a single "heterostructure" creates a material with both a large surface area and – because GeS is a semiconductor – the ability to transfer electric charges efficiently. The nanosheets provide a very large surface area, and the nanowire acts as a channel that can transmit charges between the nanosheets or from the nanosheets to another surface. This combination of features means it could be used to develop 3-D devices, such as next-generation sensors, photodetectors or solar cells. This 3-D structure could also be useful for developing new energy storage technologies, such as next-generation supercapacitors.
"We think this approach could also be used to create heterostructures like these using other materials whose molecules form similar crystalline layers, such as molybdenum sulfide (MoS2)," says Dr. Linyou Cao, an assistant professor of materials science and engineering at NC State and co-author of a paper on the research. "And, while germanium sulfide has excellent photonic properties, MoS2 holds more promise for electronic applications."
The process, Cao says, is also attractive because "it is inexpensive and could be scaled up for industrial processes."
To create the nano-shish-kebabs, the researchers begin by creating a GeS nanowire approximately 100 nanometers in width. The nanowire is then exposed to air, creating nucleation sites on the wire surface through weak oxidation. The nanowire is then exposed to GeS vapor, which forms into two-dimensional nanosheets at each of the nucleation sites.
"Our next step is to see if we can create these heterostructures in other materials, such as MoS2," Cao says. "We think we can, but we need to prove it."
The paper, "Epitaxial Nanosheet–Nanowire Heterostructures," was published online Feb. 18 in Nano Letters. The lead author is Dr. Chun Li, a former postdoctoral researcher at NC State. Co-authors are Yifei Yu, a Ph.D. student at NC State; Cao; and Dr. Miaofang Chi of Oak Ridge National Laboratory. The research was supported by the U.S. Army Research Office.
North Carolina State University: http://www.ncsu.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
A gallery of gifs showing the most beautiful fluid dynamics visualizations from the American Physical Society's Division of Fluid Mechanics 2014 annual meeting.
Popular web videos showing that "cats rule and dogs drool" have new scientific evidence to support that felinophilic sentiment, at least when it comes to drinking.
Quarks and leptons, the building blocks of matter, are staggeringly small—less than an attometer (a billionth of a billionth of a meter) in diameter. But zoom in closer—a billion times more—past zeptometers and yoctometers, to where the units run out of names. Then keep going, a hundred million times smaller still, and you finally hit bottom: This is the Planck length, the smallest possible unit in the universe.
Whether it's squeezing the uncertainty out of Heisenberg or busting the cosmic speed limit, we're outsmarting the universe to learn its secrets
Silicone material moulded into microscopic slanted wedges grip glass, metal, wood and plastic in a similar way to gecko’s feetAspiring superheroes may soon be able to climb like Spider-Man thanks to scientists working with the US military who have developed a material which enables a human to ascend a vertical glass wall.The researchers, inspired by the sticky toes of geckos, created hand-sized silicone pads covered with tiny ridges that are capable of adhering to smooth surfaces.
Researchers have developed a sensor (no batteries required) that creates a barcode indicating the amount of pollutants and their whereabouts in water
What if the unseen stuff making up 80 per cent of the universe's matter isn't a weird particle, but cosmic kinks? Then GPS satellites could reveal its effects
Bespoke lighting effects are returning the original colours to five faded masterpieces by artist Mark Rothko at Harvard Art Museums
Researchers may have come up with a way to help determine how big a future quake might be
By twisting photons into spirals as they travel, large amounts of information can be encoded in light and used for long-distance communication