Correlating the nanostructure and electronic properties of InAs nanowires

TL;DR

This study links the nanostructure and electronic properties of InAs nanowires, showing defect density impacts mobility and quantum dot formation, with optical intensity serving as a defect indicator.

Contribution

It demonstrates a correlation between defect density, optical signals, and electronic transport, highlighting a simple optical method to select high-quality nanowires.

Findings

Carrier mobility is four times higher in defect-free segments.

Dark field optical intensity correlates with mobility.

Quantum dot formation occurs at defect sites.

Abstract

The electronic properties and nanostructure of InAs nanowires are correlated by creating multiple field effect transistors (FETs) on nanowires grown to have low and high defect density segments. 4.2 K carrier mobilities are ~4X larger in the nominally defect-free segments of the wire. We also find that dark field optical intensity is correlated with the mobility, suggesting a simple route for selecting wires with a low defect density. At low temperatures, FETs fabricated on high defect density segments of InAs nanowires showed transport properties consistent with single electron charging, even on devices with low resistance ohmic contacts. The charging energies obtained suggest quantum dot formation at defects in the wires. These results reinforce the importance of controlling the defect density in order to produce high quality electrical and optical devices using InAs nanowires.