Electronic and structural properties of ultrathin germanium nanowires by density functional theory calculations

Abstract

Employing the basin-hopping method with the Stillinger–Weber potential and penalty function, four germanium nanowires with the most stable energies were obtained at cross-section radii of 1.8 Å, 2.0 Å, 2.4 Å, and 2.9 Å, respectively. Because the coordination numbers and orbital hybridizations of Ge atoms in these nanostructures are different from bulk Ge, their density of states (DOS) profiles are distinctly different from that of bulk. Besides, the discrepancies of DOS among these nanowires arising from different electron density overlaps induce the different Coulomb interactions. Furthermore, the enhanced Coulomb interaction and the quantum confinement in germanium nanowires cause the original p-orbitals below Fermi-level shift up to cross the Fermi-level, which leads Ge nanowires to be conductors.

Vapor-solid-solid grown Ge nanowires at integrated circuit compatible temperature by molecular beam epitaxy

“…Furthermore, we compare the growth orientation of Ge NWs at temperatures below and above T e shown in Fig. 5(c), in agreement with the result of Schmidtbauer et al 10 Interestingly, at a low growth temperature, lateral NWs appear along the [1][2][3][4][5][6][7][8][9][10] direction. Scrutinizing through different positions of the NW sample grown at 220 C, we found that the NWs with 30 inclination all possess a long length, thin diameter, and small Au tips, both shown in Figs.…”

“…Ge nanowires (NWs) have promising electronic properties 1,2 and play an increasingly important role in various applications, such as high speed transistors, [3][4][5] photodetectors, 6,7 and the anode material of high capacity lithium-ion batteries. 8 Conventional Ge NW growth via the Au-assisted vapor-liquid-solid (VLS) process takes place above the Au-Ge eutectic temperature (T e % 361 C).…”

Spectrum of Exfoliable 1D van der Waals Molecular Wires and Their Electronic Properties

“…Limited work exists on the properties and exfoliation potential of individual wire chains or layers of chains within the framework of van der Waals materials. Ab initio calculations have been performed on single linear chains of individual atoms such as Fe, Ge, Au, and Te − as well as different geometries of common nanowire materials SiC, GaN, BN, ZnO, ZnS, and CdS . The materials studied in this work are more complex, extending beyond monatomic or common semiconducting materials, and are known to be stable in the bulk form composed of intrinsically 1D chains.…”