Ultimate-Strength Germanium Nanowires

Ngo, Lien T.; Almecija, Dorothée; Sader, John E.; Daly, Brian; Petkov, Nikolay; Holmes, Justin D.; Erts, Donāts; Boland, John J.

doi:10.1021/nl0619397

Cited by 139 publications

(141 citation statements)

References 20 publications

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“…For all the experiments carried out with this setup, the distance between the needle and the collector was set at Solutions were electrospun for a very short time (~45 s), resulting in a low density mesh of fibers with radii between 20 and 40 nm. Mechanical measurements were performed following a technique previously developed for metallic and semiconducting wires (25)(26)(27). Scanning electron microscopy was used to monitor both the density and the position/alignment of the nanofibers across the trenches.…”

Section: Methodsmentioning

confidence: 99%

Mechanical properties of individual electrospun polymer-nanotube composite nanofibers

Almecija

Blond

Sader

et al. 2009

Carbon

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Section: Methodsmentioning

confidence: 99%

Mechanical properties of individual electrospun polymer-nanotube composite nanofibers

Almecija

Blond

Sader

et al. 2009

Carbon

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“…Experimental nanowire resonance frequencies (black circles) plotted as a function of the geometry factor G and fitted line through origin (solid line), yielding a constant Young's modulus E = (45 ± 3) GPa. The inset shows an enlarged view of the leftmost part of the plot indicated by a black rectangle, clearly demonstrating that the ten most flexible nanowires are equally well-described by the global value of E as their more rigid counterparts exhibiting a larger geometry factor G. Error bars on the G-axis include the uncertainty in determining r, R and h by SEM analysis.A possible explanation for this vast spread could be a dependence of Young's modulus on the geometric dimensions of the underlying nanowires, which is actively discussed in part of the research literature [12][13][14][15][33][34][35][36]. In order to elucidate possible size effects in our data, Young's modulus is additionally determined for each individual nanowire, again using eq.…”

mentioning

confidence: 99%

“…A possible explanation for this vast spread could be a dependence of Young's modulus on the geometric dimensions of the underlying nanowires, which is actively discussed in part of the research literature [12][13][14][15][33][34][35][36]. In order to elucidate possible size effects in our data, Young's modulus is additionally determined for each individual nanowire, again using eq.…”

mentioning

confidence: 99%

Size-independent Young's modulus of inverted conical GaAs nanowire resonators

Paulitschke

Seltner

Lebedev

et al. 2013

Applied Physics Letters

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We explore mechanical properties of top down fabricated, singly clamped inverted conical GaAs nanowires. Combining nanowire lengths of 2 − 9 µm with foot diameters of 36 − 935 nm yields fundamental flexural eigenmodes spanning two orders of magnitude from 200 kHz to 42 MHz. We extract a size-independent value of Young's modulus of (45 ± 3) GPa. With foot diameters down to a few tens of nanometers, the investigated nanowires are promising candidates for ultra-flexible and ultra-sensitive nanomechanical devices.PACS numbers: 46.70. Hg,62.20.de,62.23.Hj,62.25.Jk Keywords: Nanomechanical systems, mechanical resonators, nanowires, Young's modulusThe rise of nanotechnologies in basic research as well as the applied sciences goes along with the development of more and more compact and sensitive devices. For example, nanomechanical systems (NEMS) are promising candidates for ultra-responsive mass [1,2], force [3][4][5] or biosensors [6][7][8], as well as accelerometers [9] or oscillators [10]. The successful realization of such devices is enabled by a combination of three key factors: integrated architectures, reliable fabrication and high sensitivity. Particularly for integrated sensing devices the vertical arrangement of dense arrays of micro-or nanowires [5] is considered beneficial. A compact sensor design with higher functionality and reproducible control over device parameters is facilitated by top down fabrication. Finally, the device's sensitivity is closely related to its spring constant, which is a function of both geometry and material properties such as Young's modulus E, as, quite generally, a softer spring allows resolving smaller signals. Thus, detailed knowledge of the mechanical properties is crucial to predict the performance of a device. Typically, Young's moduli are determined by relating the measured resonance frequency f 0 of the resonator's fundamental flexural mode to its geometrical dimensions [11][12][13][14][15][16]. A prominent example is the simple singly-clamped cylindrical beam for which Euler Bernoulli beam theory [17] yields the well-known relationfor aspect ratios r/h < 0.1 with mass density ρ, beam radius r and length h.Here we present a nanomechanical resonator which is an excellent candidate for a nanomechanical sensing device. Figure 1 shows nanowires etched into an (100)-oriented GaAs substrate, combining the benefits of top down fabrication with an ultrasoft mechanical response, allowing for immediate integration into a sensing array. * present address: Universität Konstanz, Universitätsstr. 10, 78457 Konstanz, Germany; eva.weig@uni.konstanz.de Notably, the nanowires are not cylindrical, but of inverted conical shape. This is apparent from the magnified nanowire in the right part of Fig. 1 featuring a length of h = 6 µm, a head radius of R = 264 nm and a foot radius of only r = 85 nm, which corresponds to a taper angle of ϕ ≈ 1.7 • . While the narrow nanowire foots enable high force sensitivities [18,19], the relatively large nanowire heads can easily be resolved in an optical...

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“…Details of SFLS technique can be found in earlier works. 17,18 Two types of Ge NWs grown at different conditions 19 were used (referred to as "type A" 17 and "type B" (Ref.…”

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Contact resistivity and suppression of Fermi level pinning in side-contacted germanium nanowires

Koleśnik-Gray

Lutz

Collins

et al. 2013

Applied Physics Letters

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Electrical properties of contact-interfaces in germanium nanowire field effect transistor devices are studied. In contrast to planar bulk devices, it is shown that the active conduction channel and gate length extend between and underneath the contact electrodes. Furthermore, direct scaling of contact resistivity and Schottky barrier height with electrode metal function is observed. The associated pinning parameter was found to be γ=0.65 ± 0.03γ=0.65 ± 0.03, which demonstrates a significant suppression of Fermi level pinning in quasi-one-dimensional structures

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Ultimate-Strength Germanium Nanowires

Cited by 139 publications

References 20 publications

Mechanical properties of individual electrospun polymer-nanotube composite nanofibers

Mechanical properties of individual electrospun polymer-nanotube composite nanofibers

Size-independent Young's modulus of inverted conical GaAs nanowire resonators

Contact resistivity and suppression of Fermi level pinning in side-contacted germanium nanowires

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