Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > U-M physicists create first atomic-scale map of quantum dots

An atomic-scale map of the interface between an atomic dot and its substrate. Each peak represents a single atom. The map, made with high-intensity X-rays, is a slice through a vertical cross-section of the dot.
An atomic-scale map of the interface between an atomic dot and its substrate. Each peak represents a single atom. The map, made with high-intensity X-rays, is a slice through a vertical cross-section of the dot.

Abstract:
University of Michigan physicists have created the first atomic-scale maps of quantum dots, a major step toward the goal of producing "designer dots" that can be tailored for specific applications.

U-M physicists create first atomic-scale map of quantum dots

Ann Arbor, MI | Posted on September 29th, 2009

Quantum dots—often called artificial atoms or nanoparticles—are tiny semiconductor crystals with wide-ranging potential applications in computing, photovoltaic cells, light-emitting devices and other technologies. Each dot is a well-ordered cluster of atoms, 10 to 50 atoms in diameter.

Engineers are gaining the ability to manipulate the atoms in quantum dots to control their properties and behavior, through a process called directed assembly. But progress has been slowed, until now, by the lack of atomic-scale information about the structure and chemical makeup of quantum dots.

The new atomic-scale maps will help fill that knowledge gap, clearing the path to more rapid progress in the field of quantum-dot directed assembly, said Roy Clarke, U-M professor of physics and corresponding author of a paper on the topic published online Sept. 27 in the journal Nature Nanotechnology.

Lead author of the paper is Divine Kumah of the U-M's Applied Physics Program, who conducted the research for his doctoral dissertation.

"I liken it to exploration in the olden days," Clarke said of dot mapping. "You find a new continent and initially all you see is the vague outline of something through the mist. Then you land on it and go into the interior and really map it out, square inch by square inch.

"Researchers have been able to chart the outline of these quantum dots for quite a while. But this is the first time that anybody has been able to map them at the atomic level, to go in and see where the atoms are positioned, as well as their chemical composition. It's a very significant breakthrough."

To create the maps, Clarke's team illuminated the dots with a brilliant X-ray photon beam at Argonne National Laboratory's Advanced Photon Source. The beam acts like an X-ray microscope to reveal details about the quantum dot's structure. Because X-rays have very short wavelengths, they can be used to create super-high-resolution maps.

"We're measuring the position and the chemical makeup of individual pieces of a quantum dot at a resolution of one-hundredth of a nanometer," Clarke said. "So it's incredibly high resolution."

A nanometer is one-billionth of a meter.

The availability of atomic-scale maps will quicken progress in the field of directed assembly. That, in turn, will lead to new technologies based on quantum dots. The dots have already been used to make highly efficient lasers and sensors, and they might help make quantum computers a reality, Clarke said.

"Atomic-scale mapping provides information that is essential if you're going to have controlled fabrication of quantum dots," Clarke said. "To make dots with a specific set of characteristics or a certain behavior, you have to know where everything is, so that you can place the atoms optimally. Knowing what you've got is the most important thing of all."

In addition to Clarke, co-authors of the Nature Nanotechnology paper are Sergey Shusterman, Yossi Paltiel and Yizhak Yacoby.

The research was sponsored by a grant from the National Science Foundation. The U.S. Department of Energy supported work at Argonne National Laboratory's Advanced Photon Source.

####

For more information, please click here

Contacts:
Jim Erickson
Phone: (734) 647-1842

Copyright © University of Michigan

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Discoveries

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Researchers’ approach may protect quantum computers from attacks March 8th, 2024

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Quantum Dots/Rods

A new kind of magnetism November 17th, 2023

IOP Publishing celebrates World Quantum Day with the announcement of a special quantum collection and the winners of two prestigious quantum awards April 14th, 2023

Qubits on strong stimulants: Researchers find ways to improve the storage time of quantum information in a spin rich material January 27th, 2023

NIST’s grid of quantum islands could reveal secrets for powerful technologies November 18th, 2022

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project