Diameter-Dependent Electron Mobility of InAs Nanowires

TL;DR

This study investigates how the electron mobility in InAs nanowires varies with diameter, revealing that smaller nanowires exhibit reduced mobility mainly due to surface roughness scattering, using temperature-dependent electrical measurements.

Contribution

It introduces a comprehensive method combining I-V and C-V spectroscopy to directly measure intrinsic electron transport properties as a function of nanowire radius.

Findings

Mobility decreases monotonically with decreasing nanowire radius.

Surface roughness scattering significantly impacts mobility in sub-10 nm nanowires.

The approach enables detailed characterization of nanoscale electronic materials.

Abstract

Temperature-dependent I-V and C-V spectroscopy of single InAs nanowire field-effect transistors were utilized to directly shed light on the intrinsic electron transport properties as a function of nanowire radius. From C-V characterizations, the densities of thermally-activated fixed charges and trap states on the surface of untreated (i.e., without any surface functionalization) nanowires are investigated while enabling the accurate measurement of the gate oxide capacitance; therefore, leading to the direct assessment of the field-effect mobility for electrons. The field-effect mobility is found to monotonically decrease as the radius is reduced to sub-10 nm, with the low temperature transport data clearly highlighting the drastic impact of the surface roughness scattering on the mobility degradation for miniaturized nanowires. More generally, the approach presented here may serve as a versatile and powerful platform for in-depth characterization of nanoscale, electronic materials.