Browsing by Author "Bell, David"

Now showing items 1-12 of 12

    • Coaxial multishell nanowires with high-quality electronic interfaces and tunable optical cavities for ultrathin photovoltaics 

      Kempa, T. J.; Cahoon, J. F.; Kim, S.-K.; Day, R. W.; Bell, David C.; Park, Hong Gyu; Lieber, Charles M. (Proceedings of the National Academy of Sciences, 2012)
      Silicon nanowires (NWs) could enable low-cost and efficient photovoltaics, though their performance has been limited by nonideal electrical characteristics and an inability to tune absorption properties. We overcome these ...

    • Dirac Fermions and Flat Bands in the Ideal Kagome Metal FeSn 

      Fang, Shiang; Han, Minyong; Graff, David; Kaxiras, Efthimios; Kang, Mingu; Ye, Linda; You, Jhih-Shih; Levitan, Abe; Facio, Jorge; Jozwiak, Chris; Bostwick, Aaron; Rotenberg, Eli; Chan, Mun; McDonald, Ross; Kaznatcheev, Konstantine; Vescovo, Elio; Bell, David; van den Brink, Jeroen; Richter, Manuel; Prasad Ghimire, Madhav; Checkelsky, Joseph; Comin, Riccardo (Springer Science and Business Media LLC, 2019-12-09)
      A kagome lattice of 3d transition metal ions is a versatile platform for correlated topological phases hosting symmetry-protected electronic excitations and magnetic ground states. However, the paradigmatic states of the ...

    • Direct Imaging of Atomic-Scale Ripples in Few-Layer Graphene 

      Wang, Wei Li; Bhandari, Sagar; Yi, Wei; Bell, David C.; Westervelt, Robert M.; Kaxiras, Efthimios (American Chemical Society, 2012)
      Graphene has been touted as the prototypical two-dimensional solid of extraordinary stability and strength. However, its very existence relies on out-of-plane ripples as predicted by theory and confirmed by experiments. ...

    • Epitaxial Catalyst-Free Growth of InN Nanorods on c-Plane Sapphire 

      Shalish, Ilan; Seryogin, G.; Yi, W.; Bao, J. M.; Zimmler, M. A.; Likovich, Edward Michael; Bell, David C.; Capasso, Federico; Narayanamurti, Venkatesh (Springer-Verlag, 2009)
      We report observation of catalyst-free hydride vapor phase epitaxy growth of InN nanorods. Characterization of the nanorods with transmission electron microscopy, and X-ray diffraction show that the nanorods are stoichiometric ...

    • Etching of Graphene Devices with a Helium Ion Beam 

      Lemme, Max C.; Bell, David C.; Williams, James R.; Stern, Lewis A.; Baugher, Britton W. H.; Jarillo-Herrero, Pablo; Marcus, Charles Masamed (American Chemical Society, 2009)
      We report on the etching of graphene devices with a helium ion beam, including in situ electrical measurement during lithography. The etching process can be used to nanostructure and electrically isolate different regions ...

    • Ion-sculpting of Nanopores in Amorphous Metals, Semiconductors and Insulators 

      George, H. Bola; Hoogerheide, David Paul; Madi, Charbel S.; Bell, David C.; Golovchenko, Jene A.; Aziz, Michael J. (American Institute of Physics, 2010)
      We report the closure of nanopores to single-digit nanometer dimensions by ion sculpting in a range of amorphous materials including insulators (SiO\(_2\) and SiN), semiconductors (a-Si), and metallic glasses (Pd\(_{80}\ ...

    • Nanowire-Induced Wurtzite InAs Thin Film on Zinc-Blende InAs Substrate 

      Bao, Jiming; Bell, David C.; Capasso, Federico; Erdman, Natasha; Wei, Dongguang; Froeberg, Linus; Martensson, Thomas; Samuelson, Lars (Wiley-Blackwell, 2009)

    • Precision Cutting and Patterning of Graphene with Helium Ions 

      Bell, David C.; Lemme, Max; Stern, L. A.; Williams, J. R.; Marcus, Charles Masamed (Institute of Physics, 2009)
      We report nanoscale patterning of graphene using a helium ion microscope configured for lithography. Helium ion lithography is a direct-write lithography process, comparable to conventional focused ion beam patterning, ...

    • Strengthening of Ceramic-based Artificial Nacre via Synergistic Interactions of 1D Vanadium Pentoxide and 2D Graphene Oxide Building Blocks 

      Knöller, Andrea; Lampa, Christian P.; Cube, Felix von; Zeng, Tingying Helen; Bell, David C.; Dresselhaus, Mildred S.; Burghard, Zaklina; Bill, Joachim (Nature Publishing Group, 2017)
      Nature has evolved hierarchical structures of hybrid materials with excellent mechanical properties. Inspired by nacre’s architecture, a ternary nanostructured composite has been developed, wherein stacked lamellas of 1D ...

    • Synthetically Encoded Ultrashort-Channel Nanowire Transistors for Fast, Pointlike Cellular Signal Detection 

      Cohen-Karni, Tzahi; Casanova, Didier; Cahoon, James F.; Qing, Quan; Bell, David C.; Lieber, Charles M. (American Chemical Society, 2012)
      Nanostructures, which have sizes comparable to biological functional units involved in cellular communication, offer the potential for enhanced sensitivity and spatial resolution compared to planar metal and semiconductor ...

    • Topological Graphene Imaging and Fabrication of Devices 

      Bell, David C.; Wang, Wei Li; Bhandari, Sagar; Westervelt, Robert M.; Kaxiras, Efthimios (Microscopy Society of America, 2012)

    • Transition-Metal Single Atoms in a Graphene Shell as Active Centers for Highly Efficient Artificial Photosynthesis 

      Jiang, Kun; Siahrostami, Samira; Akey, Austin; Li, Yanbin; Lu, Zhiyi; Lattimer, Judith; Hu, Yongfeng; Stokes, Richard C.; Gangishetty, Mahesh; Chen, Guangxu; Zhou, Yawei; Hill, I. Winfield; Cai, Wen-Bin; Bell, David C.; Chan, Karen; Nørskov, Jens K.; Cui, Yi; Wang, Haotian (Elsevier BV, 2017)
      Utilizing solar energy to fix carbon dioxide (CO2) with water into chemical fuels and oxygen, a mimic process of photosynthesis in nature, is becoming increasingly important but still challenged by the low selectivity and ...