Effect of Si-doping on InAs nanowire transport and morphology

Abstract

The effect of Si-doping on the morphology, structure, and transport properties of nanowires was investigated. The nanowires were deposited by selective-area metal organic vapor phase epitaxy in an N 2 ambient. It is observed that doping systematically affects the nanowire morphology but not the structure of the nanowires. However, the transport properties of the wires are greatly affected. Room-temperature four-terminal measurements show that with an increasing dopant supply the conductivity monotonously increases. For the highest doping level the conductivity is higher by a factor of 25 compared to only intrinsically doped reference nanowires. By means of back-gate field-effect transistor measurements it was confirmed that the doping results in an increased carrier concentration. Temperature dependent resistance measurements reveal, for lower doping concentrations, a thermally activated semiconductor-type increase of the conductivity. In contrast, the nanowires with the highest doping concentration show a metal-type decrease of the resistivity with decreasing temperature.

Magnetoconductance correction in zinc-blende semiconductor nanowires with spin-orbit coupling

“…As previously shown [14,30,36], the electrons in undoped InAs nanowires are confined to a narrow layer beneath the surface due to Fermi level pinning and the transport is governed by surface states. However, a controlled doping allows the electrons to distribute over the entire volume and thereby change the dimensionality and transport topology to that of a quasi-3D channel [25,30,36].…”

“…More precisely, one is able to effectively control the size, morphology, potential landscape, carrier, and impurity concentration, or even crystal structure [12,[22][23][24][25][26][27][28][29][30][31]. Since typically both the SOC and the WAL/WL correction strongly depend on these characteristics, the great diversity makes it difficult to build up a general theoretical description.…”

“…The WAL/WL effect in the diffusive regime was analyzed by Kettemann [32] and Wenk [33,34] for planar quantum wires with a zinc-blende lattice. In our preceding article [14], we developed a model for diffusive zinc-blende nanowires where the transport is governed by surface states, which occurs in materials with Fermi level surface pinning [12,25,30,35,36] or core/shell nanowires [26].…”

Investigations of local electronic transport in InAs nanowires by scanning gate microscopy at liquid helium temperatures

“…In the past decade considerable interest was devoted to investigations of electronic transport of individual one-dimensional mesoscopic systems such as carbon nanotubes (CNT) and nanowires (InAs, InN) [1][2][3][4][5][6][7][8]. Usually, for such experiments field-effect transistors are fabricated from individual one-dimensional (1D) objects by forming metallic contacts by electron-beam lithography.…”

Manipulating InAs nanowires with submicrometer precision

“…This revealed a mobility of roughly 1000 cm 2 /Vs and a carrier concentration of 2 × 10 18 cm −3 which is typical for InAs nanowires. 8,31,32 The four-terminal magnetoconductance measurements of the suspended wire are performed by a lock-in amplifier providing an ac current signal to the outer contacts with an amplitude of 5 nA and a frequency of 17. More detailed results using this sample will be published in Ref.…”