Sep 05, 2013 |
Nanoengineers make golden breakthrough to improve electronic devices
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(Nanowerk News) A Kansas State University chemical engineer has discovered that a new member of the ultrathin materials family has great potential to improve electronic and thermal devices.
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Vikas Berry, William H. Honstead professor of chemical engineering, and his research team have studied a new three-atom-thick material -- molybdenum disulfide -- and found that manipulating it with gold atoms improves its electrical characteristics. Their research appears in a recent issue of Nano Letters ("Controlled, Defect-Guided, Metal-Nanoparticle Incorporation onto MoS2 via Chemical and Microwave Routes: Electrical, Thermal, and Structural Properties").
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Vikas Berry, William H. Honstead professor of chemical engineering, and his research team have studied a new three-atom-thick material -- molybdenum disulfide -- and found that manipulating it with gold atoms improves its electrical characteristics.
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The research may advance transistors, photodetectors, sensors and thermally conductive coatings, Berry said. It could also produce ultrafast, ultrathin logic and plasmonics devices.
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Berry's laboratory has been leading studies on synthesis and properties of several next-generation atomically thick nanomaterials, such as graphene and boron-nitride layers, which have been applied for sensitive detection, high-rectifying electronics, mechanically strong composites and novel bionanotechnology applications.
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"Futuristically, these atomically thick structures have the potential to revolutionize electronics by evolving into devices that will be only a few atoms thick," Berry said.
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For the latest research, Berry and his team focused on transistors based on molybdenum disulfide, or MoS2, which was isolated only two years ago. The material is made of three-atom-thick sheets and has recently shown to have transistor-rectification that is better than graphene, which is a single-atom-thick sheet of carbon atoms.
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When Berry's team studied molybdenum disulfide's structure, they realized that the sulfur group on its surface had a strong chemistry with noble metals, including gold. By establishing a bond between molybdenum disulfide and gold nanostructures, they found that the bond acted as a highly coupled gate capacitor.
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Berry's team enhanced several transistor characteristics of molybdenum disulfide by manipulating it with gold nanomaterials.
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"The spontaneous, highly capacitive, lattice-driven and thermally-controlled interfacing of noble metals on metal-dichalcogenide layers can be employed to regulate their carrier concentration, pseudo-mobility, transport-barriers and phonon-transport for future devices," Berry said.
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The work may greatly improve future electronics, which will be ultrathin, Berry said. The researchers have developed a way to reduce the power that is required to operate these ultrathin devices.
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"The research will pave the way for atomically fusing layered heterostructures to leverage their capacitive interactions for next-generation electronics and photonics," Berry said. "For example, the gold nanoparticles can help launch 2-D plasmons on ultrathin materials, enabling their interference for plasmonic-logic devices."
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The research also supports the current work on molybdenum disulfide-graphene-based electron-tunneling transistors by providing a route for direct electrode attachment on a molybdenum disulfide tunneling gate.
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"The intimate, highly capacitive interaction of gold on molybdenum disulfide can induce enhanced pseudo-mobility and act as electrodes for heterostructure devices," said T.S. Sreeprasad, a postdoctoral researcher in Berry's group.
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The researchers plan to create further complex nanoscale architectures on molybdenum disulfide to build logic devices and sensors.
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"The incorporation of gold into molybdenum disulfide provides an avenue for transistors, biochemical sensors, plasmonic devices and catalytic substrate," said Phong Nguyen, a doctoral student in chemical engineering, Wichita, Kan., who is part of Berry's research team.
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Namhoon Kim, master's student in grain science and industry, Korea,worked on the research as an undergraduate in chemical engineering.
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