A forest of nanorods: Amazing nanostructures created by glancing-angle deposition

October 20, 2010

Just as landscape photographs shot in low-angle light dramatically accentuate subtle swales and mounds, depositing metal vapors at glancing angles turns a rough surface into amazing nanostructures with a vast range of potential properties.

For decades, has been a standard technique for creating modern microelectronic circuits. But nearly all of industry's efforts have been devoted to making structures as flat and smooth as possible. Rather than placing metal sources in the high-noon position used to make featureless structures, Daniel Gall of Rensselaer Polytechnic Institute is one of several dozen research leaders who place them at very narrow angles akin to sunrise or sunset illumination. Metal atoms then hit primarily any high spots on the target surface. Continued deposition creates a forest of nanorods, rather than flat films, since each growing rod shadows a volume behind it. Starting with a patterned substrate yields a regular array of nanoscale columns, like skyscrapers in downtown Manhattan.

Gall describes his research today at the AVS 57th International Symposium & Exhibition, which takes place this week at the Albuquerque Convention Center in New Mexico.

In his talk, Gall reveals a new theory that predicts how the deposition temperature and diffusion affects the diameters of the nanorods.

" moving by surface diffusion typically smooth the surface," Gall says. "Atomic shadowing causes the opposite effects, making the rough. Glancing-angle deposition extends shadowing effects to higher temperatures, which lead to larger-diameter ."

He also illustrates his presentation with images of a variety of created in his lab, including curiously shaped half-moons made when he started with a pattern of self-assembled spheres.

Future applications for nanorod structures such as Gall's include nanosensors, optical elements, fuel-cell cathodes and electrical contacts for buffering thermal expansion.

Explore further: Simple method may improve computer memory, catalysts, ceramic/metal seals, and nanodevices

More information: The presentation, "Nanorods by Extreme Shadowing: New Pictures and New Physics" is at 2:40 p.m. on Wednesday, October 20, 2010. ABSTRACT: www.avssymposium.org/Open/SearchPapers.aspx?PaperNumber=SE+TF-WeA-3

Related Stories

Recommended for you

Cooling graphene-based film close to pilot-scale production

April 29, 2016

Heat dissipation in electronics and optoelectronics is a severe bottleneck in the further development of systems in these fields. To come to grips with this serious issue, researchers at Chalmers University of Technology ...

Personal cooling units on the horizon

April 28, 2016

Firefighters entering burning buildings, athletes competing in the broiling sun and workers in foundries may eventually be able to carry their own, lightweight cooling units with them, thanks to a nanowire array that cools, ...

Exploring phosphorene, a promising new material

April 28, 2016

Two-dimensional phosphane, a material known as phosphorene, has potential application as a material for semiconducting transistors in ever faster and more powerful computers. But there's a hitch. Many of the useful properties ...

Researchers create one-step graphene patterning method

April 27, 2016

Researchers from the University of Illinois at Urbana-Champaign have developed a one-step, facile method to pattern graphene by using stencil mask and oxygen plasma reactive-ion etching, and subsequent polymer-free direct ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.