Tag Archives: frank ogletree

Precision Growth of Light-emitting Nanowires

Berkeley Lab team shows metal-alloy catalysts give more control in nanowire fabrication.

A novel approach to growing nanowires promises a new means of control over their light-emitting and electronic properties. In a recent issue of Nano Letters, scientists from the U.S. Department of Energy’s Lawrence Berkeley National Lab (Berkeley Lab) demonstrated a new growth technique that uses specially engineered catalysts. These catalysts, which are precursors to growing the nanowires, have given scientists more options than ever in turning the color of light-emitting nanowires. (more…)

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Cooling Microprocessors with Carbon Nanotubes

Technique From Berkeley Lab’s Molecular Foundry Could Also Work with Graphene

“Cool it!” That’s a prime directive for microprocessor chips and a promising new solution to meeting this imperative is in the offing. Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a “process friendly” technique that would enable the cooling of microprocessor chips through carbon nanotubes.

Frank Ogletree, a physicist with Berkeley Lab’s Materials Sciences Division, led a study in which organic molecules were used to form strong covalent bonds between carbon nanotubes and metal surfaces. This improved by six-fold the flow of heat from the metal to the carbon nanotubes, paving the way for faster, more efficient cooling of computer chips. The technique is done through gas vapor or liquid chemistry at low temperatures, making it suitable for the manufacturing of computer chips. (more…)

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Seeing in Color at the Nanoscale

Berkeley Lab scientists develop a new nanotech tool to probe solar-energy conversion

If nanoscience were television, we’d be in the 1950s. Although scientists can make and manipulate nanoscale objects with increasingly awesome control, they are limited to black-and-white imagery for examining those objects. Information about nanoscale chemistry and interactions with light—the atomic-microscopy equivalent to color—is tantalizingly out of reach to all but the most persistent researchers.

But that may all change with the introduction of a new microscopy tool from researchers at the Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) that delivers exquisite chemical details with a resolution once thought impossible. The team developed their tool to investigate solar-to-electric energy conversion at its most fundamental level, but their invention promises to reveal new worlds of data to researchers in all walks of nanoscience. (more…)

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Berkeley Lab Researchers Create Next-Generation Chemical Mapping on the Nanoscale

A pixel is worth a thousand words? Not exactly how the saying goes, but in this case, it holds true: scientists at Berkeley Lab’s Molecular Foundry have pioneered a new chemical mapping method that provides unprecedented insight into materials at the nanoscale. Moving beyond traditional static imaging techniques, which provide a snapshot in time, these new maps will guide researchers in deciphering molecular chemistry and interactions at the nanoscale—critical for artificial photosynthesis, biofuels production and light-harvesting applications such as solar cells.

“This new technique allows us to capture very high-resolution images of nanomaterials with a huge amount of physical and chemical information at each pixel,” says Alexander Weber-Bargioni, a postdoctoral scholar in the Imaging and Manipulation of Nanostructures Facility at the Foundry. “Usually when you take an image, you just get a picture of what this material looks like, but nothing more. With our method, we can now gain information about the functionality of a nanostructure with rich detail.” (more…)

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