Optoelectronic control of surface charge and translocation dynamics in solid-state nanopores

Nature Nanotechnology 8, 946 (2013). doi:10.1038/nnano.2013.221

Authors: Nicolas Di Fiori, Allison Squires, Daniel Bar, Tal Gilboa, Theodore D. Moustakas & Amit Meller

Nicolas Di Fiori

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Highly efficient gate-tunable photocurrent generation in vertical heterostructures of layered materials

Nature Nanotechnology 8, 952 (2013). doi:10.1038/nnano.2013.219

Authors: Woo Jong Yu, Yuan Liu, Hailong Zhou, Anxiang Yin, Zheng Li, Yu Huang & Xiangfeng Duan

Woo Jong Yu

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Nanoimaging: Hot electrons go through the barrier

Nature Nanotechnology 8, 799 (2013). doi:10.1038/nnano.2013.228

Author: P. James Schuck

Hot electrons can be efficiently injected into a semiconductor using a metallic tip that focuses surface plasmons, and can be used to carry out nanoscale chemical mapping.

P. James Schuck

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Surface plasmons: A probe for graphene electronics

Nature Nanotechnology 8, 802 (2013). doi:10.1038/nnano.2013.220

Author: Rémi Carminati

The local electronic properties of graphene grain boundaries can be obtained by deciphering the interference patterns produced by surface plasmons.

Rémi Carminati

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Electronic and plasmonic phenomena at graphene grain boundaries

Nature Nanotechnology 8, 821 (2013). doi:10.1038/nnano.2013.197

Authors: Z. Fei, A. S. Rodin, W. Gannett, S. Dai, W. Regan, M. Wagner, M. K. Liu, A. S. McLeod, G. Dominguez, M. Thiemens, Antonio H. Castro Neto, F. Keilmann, A. Zettl, R. Hillenbrand, M. M. Fogler & D. N. Basov

Z. Fei

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Graphene–MoS2 hybrid structures for multifunctional photoresponsive memory devices

Nature Nanotechnology 8, 826 (2013). doi:10.1038/nnano.2013.206

Authors: Kallol Roy, Medini Padmanabhan, Srijit Goswami, T. Phanindra Sai, Gopalakrishnan Ramalingam, Srinivasan Raghavan & Arindam Ghosh

Kallol Roy

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Multivalent ligands control stem cell behaviour in vitro and in vivo

Nature Nanotechnology 8, 831 (2013). doi:10.1038/nnano.2013.205

Authors: Anthony Conway, Tandis Vazin, Dawn P. Spelke, Nikhil A. Rode, Kevin E. Healy, Ravi S. Kane & David V. Schaffer

Anthony Conway

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Nucleation, stability and current-induced motion of isolated magnetic skyrmions in nanostructures

Nature Nanotechnology 8, 839 (2013). doi:10.1038/nnano.2013.233

Authors: J. Sampaio, V. Cros, S. Rohart, A. Thiaville & A. Fert

J. Sampaio

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Hot-electron nanoscopy using adiabatic compression of surface plasmons

Nature Nanotechnology 8, 845 (2013). doi:10.1038/nnano.2013.207

Authors: A. Giugni, B. Torre, A. Toma, M. Francardi, M. Malerba, A. Alabastri, R. Proietti Zaccaria, M. I. Stockman & E. Di Fabrizio

A. Giugni

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Direct probing of the exchange interaction at buried interfaces

Nature Nanotechnology 8, 853 (2013). doi:10.1038/nnano.2013.188

Authors: Kh. Zakeri, T.-H. Chuang, A. Ernst, L. M. Sandratskii, P. Buczek, H. J. Qin, Y. Zhang & J. Kirschner

Kh. Zakeri

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Formation and electronic properties of InSb nanocrosses

Nature Nanotechnology 8, 859 (2013). doi:10.1038/nnano.2013.198

Authors: Sébastien R. Plissard, Ilse van Weperen, Diana Car, Marcel A. Verheijen, George W. G. Immink, Jakob Kammhuber, Ludo J. Cornelissen, Daniel B. Szombati, Attila Geresdi, Sergey M. Frolov, Leo P. Kouwenhoven & Erik P. A. M. Bakkers

Sébastien R. Plissard

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A general strategy for the DNA-mediated self-assembly of functional nanoparticles into heterogeneous systems

Nature Nanotechnology 8, 865 (2013). doi:10.1038/nnano.2013.209

Authors: Yugang Zhang, Fang Lu, Kevin G. Yager, Daniel van der Lelie & Oleg Gang

Yugang Zhang

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In vivo biosensing via tissue-localizable near-infrared-fluorescent single-walled carbon nanotubes

Nature Nanotechnology 8, 873 (2013). doi:10.1038/nnano.2013.222

Authors: Nicole M. Iverson, Paul W. Barone, Mia Shandell, Laura J. Trudel, Selda Sen, Fatih Sen, Vsevolod Ivanov, Esha Atolia, Edgardo Farias, Thomas P. McNicholas, Nigel Reuel, Nicola M. A. Parry, Gerald N. Wogan & Michael S. Strano

Nicole M. Iverson

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Characteristics of a pressure sensitive touch sensor using a piezoelectric PVDF-TrFE/MoS 2 stack

A new touch sensor device has been demonstrated with molybdenum disulfide (MoS 2 ) field effect transistors stacked with a piezoelectric polymer, polyvinylidene fluoride–trifluoroethylene (PVDF–TrFE). The performance of two device stack structures, metal/PVDF–TrFE/MoS 2 (MPM) and metal/PVDF–TrFE/Al 2 O 3 /MoS 2 (MPAM), were compared as a function of the thickness of PVDF–TrFE and Al 2 O 3 . The sensitivity of the touch sensor has been improved by two orders of magnitude by reducing the charge scattering and enhancing the passivation effects using a thin Al 2 O 3 interfacial layer. Reliable switching behavior has been demonstrated up to 120 touch press cycles.

Woojin Park, Jin Ho Yang, Chang Goo Kang, Young Gon Lee, Hyeon Jun Hwang, Chunhum Cho, Sung Kwan Lim, Soo Cheol Kang, Woong-Ki Hong, Sang Kyung Lee, Sangchul Lee and Byoung Hun Lee

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3D hierarchical architectures based on self-rolled-up silicon nitride membranes

This study presents the superior structural versatility of strained silicon nitride (SiN x ) membranes as a platform for three-dimensional (3D) hierarchical tubular architectures. The effects of compressive and tensile stressed SiN x layer thickness on the self-rolled-up tube curvature, the sacrificial layer etching anisotropy on rolling direction and chirality, and stress engineering by localized thickness control or thermal treatment, are explored systematically. Using strained SiN x membranes as an electrically insulating and optically transparent mechanical support, compact 3D hierarchical architectures involving carbon nanotube arrays and passive electronic components are demonstrated by releasing the functional structures deposited and patterned in 2D. These examples highlight the uniqueness of this platform that exploits 2D processing and self-assembly to achieve highly functional 3D structures.

Paul Froeter, Xin Yu, Wen Huang, Frank Du, Moyang Li, Iksu Chun, Seung Hyun Kim, Kuen J Hsia, John A Rogers and Xiuling Li

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Charge and spin transport in PEDOT:PSS nanoscale lateral devices

The electrical transport of the highly conductive poly-(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) is investigated with Ohmic and spin-polarized tunnel contacts at nanoscale lateral dimensions. Temperature-dependent charge transport measurements reveal that electrical conductivity scales non-linearly as a function of electrode spacing, which is attributed to the localization of carriers induced by the disorder introduced by the PSS polyelectrolyte. In addition, we demonstrate the integration of this conducting polymer in nanoscale lateral spin-valve devices by increasing the pH of the PEDOT:PSS solution. We present charge and magnetotransport measurement results of NiFe/AlO x /PEDOT:PSS/AlO x /NiFe lateral structures for various thicknesses of the alumina tunnel barriers. We discuss the absence of magnetoresistance of our spin valves within the framework of Valet–Fert theory, and estimate an upper limit for the spin lifetime...

Thales V A G de Oliveira, Marco Gobbi, José M Porro, Luis E Hueso and Alexander M Bittner

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Rice-straw-like structure of silicon nanowire arrays for a hydrogen gas sensor

A rice-straw-like silicon nanowire (SiNW) array was developed for hydrogen gas sensing applications. The straight-aligned SiNW array sensor was first fabricated by the metal-assisted electroless etching (MAEE) technique. Rice-straw-like SiNW arrays were formed using a repeated MAEE technique. Hydrogen sensing characteristics were measured for gas concentrations from 20 to 1000 ppm at room temperature. The rice-straw-like SiNW-array-based hydrogen gas sensor performed with low noise and a high response (232.5%) for 1000 ppm hydrogen gas. It was found that the rice-straw-like SiNW-array hydrogen gas sensor had a much better response (approximately 2.5 times) than the straight-aligned SiNW-array sensor. The rice-straw-like SiNW-array structure effectively increased the surface area and the concentration of silicon oxide, which provided additional binding sites for gas molecules. Thus, the rice-straw-like SiNW-array-based hydrogen gas sensor possessed good sensing properties and has ...

Bohr-Ran Huang, Ying-Kan Yang and Hsien-Lung Cheng

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Co nanostructures in ordered templates: comparative FORC analysis

A comparative study on the structural and magnetic properties of highly ordered hexagonal arrays of Co nanoholes, nanowires, nanopillars and nanotubes, with tuned pore/wire/tube diameters, is here presented. The magnetic interactions and their dependence on the geometric features of the arrays were studied using first-order reversal curves (FORCs). For all nanostructures we observe an increase of the magnetostatic interactions with the templates’ pore diameter, with the higher (smaller) values found for the nanowire (nanohole) arrays. For the smallest diameters studied (35 nm), all types of arrays could be considered as almost isolated nanostructures, where local interactions prevail. In particular, both nanotube and nanohole arrays exhibit considerable local magnetostatic interactions coming from the stray fields within each void or empty core. On the other hand, the coercivity is found to decrease with diameter for the elongated nanostructures, while it increases with the pore ...

M P Proenca, K J Merazzo, L G Vivas, D C Leitao, C T Sousa, J Ventura, J P Araujo and M Vazquez

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Cantilever energy effects on bimodal AFM: phase and amplitude contrast of multicomponent samples

Bimodal atomic force microscopy (AFM) is a recently developed technique of dynamic AFM where a higher eigenmode of the cantilever is simultaneously excited along with the fundamental eigenmode. The effects of different operating parameters while imaging an impact copolymer blend of polypropylene (PP) and ethylene–propylene (E–P) rubber in bimodal mode are explored through experiments and numerical simulations. The higher mode amplitude and phase contrasts between the two components of the sample reverse at different points as the free amplitude of the higher eigenmode is increased. Three different regimes are identified experimentally depending on the relative contrast between the PP and the E–P rubber. It is observed that the kinetic energy and free air drive input energy of the two cantilever eigenmodes play a role in determining the regimes of operation. Numerical simulations conducted with appropriate tip–sample interaction forces support the experimental results. An understa...

Ishita Chakraborty and Dalia G Yablon

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Shadowing and mask opening effects during selective-area vapor–liquid–solid growth of InP nanowires by metalorganic molecular beam epitaxy

Indium phosphide nanowires were grown by metalorganic molecular beam epitaxy using the selective-area vapor–liquid–solid method. We show experimentally and theoretically that the size of the annular opening around the nanowire has a major impact on nanowire growth rate. In addition, we observed a considerable reduction of the growth rate in dense two-dimensional arrays, in agreement with a calculation of the shadowing of the scattered precursors. Due to the impact of these effects on growth, they should be considered during selective-area vapor–liquid–solid nanowire epitaxy.

A Kelrich, Y Calahorra, Y Greenberg, A Gavrilov, S Cohen and D Ritter

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