Electrical transport properties of single-crystal Al nanowires

Abstract

Single-crystal Al nanowires (NWs) were fabricated by thermally induced substitution of vapor-liquid-solid grown Ge NWs by Al. The resistivity of the crystalline Al (c-Al) NWs was determined to be ρ = (131 ± 27) × 10(-9) Ω m, i.e. approximately five times higher than for bulk Al, but they withstand remarkably high current densities of up to 1.78 × 10(12) A m(-2) before they ultimately melt due to Joule heating. The maximum current density before failure correlates with the NW diameter, with thinner NWs tolerating significantly higher current densities due to efficient heat dissipation and the reduced lattice heating in structures smaller than the electron-phonon scattering length. The outstanding current-carrying capacity of the c-Al NWs clearly exceeds those of common conductors and surpasses requirements for metallization of future high-performance devices. The linear temperature coefficient of the resistance of c-Al NWs appeared to be lower than for bulk Al and a transition to a superconducting state in c-Al NWs was observed at a temperature of 1.46 K.

Reversible Al Propagation in SixGe1–x Nanowires: Implications for Electrical Contact Formation

“…The reacted Al metal part has a low resistance. 27 Therefore, in the case of this same process in pure Ge NWs, the resistance of the remaining Ge region will become smaller and smaller as its length is reduced, since it is resistivity will not change significantly. In the experiments with Al propagation in Si 0.67 Ge 0.33 NWs, we observe the opposite effect: the NW becomes much more resistive, even when its total volume has become much smaller.…”

Spatially resolved thermoelectric effects inoperandosemiconductor–metal nanowire heterostructures

“…Indeed, this value is three times lower than previously determined for pure c-Al wires. 19 However, in an SThM scan of such an operating c-Al wire a dominant local heat source is identified in the center (see the temperature profiles in the ESI †). This may be expected according to the wire fabrication and indicates a grain boundary.…”

“…Further information on the fabrication, electrical and structural characterization of the device can be found in the ESI † and in ref. [18][19][20]. The thermoelectric figure of merit can thus be calculated from a single measurement collecting the complementary information from the Joule and the Peltier signals.…”

In-Situ Transmission Electron Microscopy Imaging of Aluminum Diffusion in Germanium Nanowires for the Fabrication of Sub-10 nm Ge Quantum Disks

“…The segment length of this Ge disk was intentionally stopped at 8 nm for further investigations. Indeed, it is also possible to perform a complete Al-Ge exchange for the fabrication of a monocrystalline Al NW 21 . Figure 5c shows an HR-HAADF-STEM image of the interface between the reacted and unreacted part with the corresponding FFT in the inserted figure.…”