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    Group Photo after Todd Day's Thesis Defense

    T.Day, S.Aro, D.Keefer, S.Juhl, T.Fitzgibbons, J.Badding, J.Bischoff, J.Song, R.Ahn, M.Coco.; X.Li, Y.Liu, A.Leone, Y.Cheng, P.Ray; Missing: S.Chaudhuri

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    Carbon Nanothreads from Benzene

    Benzene columns react to form diamondoid nanothreads: Nature Materials, DOI:10.1038/nmat4088

  • Confined Deposition
    High Pressure Chemistry for Electronic Devices

    Layering of high speed Pt-Si photodiodes into extreme aspect ratio pores: Nature Photonics, v.6, p.174 (2012)

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    Photovoltaic silicon p-i-n Junction Fibers

    1 m long silicon p-i-n junctions and 10 m long silicon layers: Advanced Materials, v.25, p.1461 (2013)

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    Confined Chemical Deposition

    Templated growth of amorphous hydrogenated silicon: J.Am.Chem.Soc. v.134, p.19 (2012)

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    Silane Unimolecular Rate Constant vs Pressure

    Acceleration of reaction rate allows for plasma-free, 100% efficient deposition of a-Si:H, an important solar cell material.

    J.Am.Chem.Soc. v.134, p.19 (2012)

  • ZnSe Wire
    Atomically Smooth Zinc Selenide Wires

    Uniform crystal field environment for transition metal doping that enables light emission:Adv. Mater. v.23, p.1647 (2011)

  • Confined Deposition
    Raman of Molecular Monolayers in Silica Pores

    Langmuir v.27 p.630 (2011)

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    Void-free filling of Extreme Aspect Ratio Templates

    Centimeters long silicon nanowires and nanopores: Adv. Mater. v.22, p.4605 (2010)


Research Overview



General Theme

Our recent experiments have shown that ordered carbon nanomaterials with unprecedented chemical structures can be synthesized via these methods.

A unifying theme in the Badding group's research is the use of pressure to synthesize or probe solid state materials. We are interested in materials that have unusual micro or nano structure or chemical/physical behavior and often apply them to problems of significant technological interest. Photonic materials, energy materials for photovoltaics and hydrogen storage, and high strength carbon nanomaterials have recently been of particular interest. Our recent experiments have shown that ordered carbon nanomaterials with unprecedented chemical structures can be synthesized via these methods. The synthesis and probing of these materials is often done in confined geometries that allow for unique nanostructures and/or a desired control over chemical and physical behavior.

Pressure is a thermodynamic variable that is as fundamental as temperature, but is underutilized in materials chemistry research.

Pressure is a thermodynamic variable that is as fundamental as temperature, but is underutilized in materials chemistry research. It can, for example, control interatomic distance (without much variation in other quantities such as the entropy), tune reaction chemical kinetics and thermodynamics (often over a much wider range than is possible with temperature), allow for solvents with hybrid liquid-like and gas-like properties, and infiltrate molecules and materials into near atomic scale voids. Superior materials properties or interesting behavior not possible without the use of pressure for chemical synthesis or tuning can thus be obtained. At the micro and nano scales, high pressure chemistry becomes much more straightforward and practical because pressure is force per unit area and the forces involved become very small as the area decreases. We use a wide range of pressure from just above atmospheric (0.1 megapascals) to tens of gigapascals.

Funding

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We thank the National Science Foundation (DMR-1107894, DMR-1431408), the Defense Advanced Research Projects Agency (PULSE and Extended Solids Projects), the Carnegie Institution of Washington EFREE I and EFREE II DOE Energy Frontier Research Centers, the Air Force (Center of Excellence in Infrared Optical Materials), and the Penn State MRSEC, funded by National Science Foundation DMR-0820404, for current support.



News


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Tom Fitzgibbons New Job


Congratulations to Tom Fitzgibbons on defending his thesis and his new job at Dow, where he will be joining recent group graduate Justin Sparks. Tom's work will continue to use synchrotron and neutron sources for characterization of complex materials.

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Rongrui He's Paper in Advanced Materials


Rongrui He, now at Intel, has published a paper in Advanced Materials on silicon p-i-n photovoltaic fibers. This paper also describes deposition of silicon in fiber pores over lengths of 10 m. Photovoltaic fibers may allow for solar fabrics upon further development.