Correlation between Electrical Transport and Nanoscale Strain in InAs/In_0.6Ga_0.4As Core–Shell Nanowires

Abstract

Free-standing semiconductor nanowires constitute an ideal material system for the direct manipulation of electrical and optical properties by strain engineering. In this study, we present a direct quantitative correlation between electrical conductivity and nanoscale lattice strain of individual InAs nanowires passivated with a thin epitaxial In0.6Ga0.4As shell. With an in situ electron microscopy electromechanical testing technique, we show that the piezoresistive response of the nanowires is greatly enhanced compared to bulk InAs, and that uniaxial elastic strain leads to increased conductivity, which can be explained by a strain-induced reduction in the band gap. In addition, we observe inhomogeneity in strain distribution, which could have a reverse effect on the conductivity by increasing the scattering of charge carriers. These results provide a direct correlation of nanoscale mechanical strain and electrical transport properties in free-standing nanostructures.

Advances in in situ nanomechanical testing

“…For example, it is possible to investigate rate effects 35 or combine multimodal testing capabilities such as simultaneous electrical and mechanical measurements. 36 The flexibility of microelectromechanical systems devices leads to adaptation for high cycle fatigue, in situ wear and environmental testing. Future designs integrating control of temperature, liquids, and electrochemistry will provide insight into operando conditions of materials deformation.…”

Functional Materials Under Stress: In Situ TEM Observations of Structural Evolution

“…As in-situ nanomechanical testing is usually conducted irreversibly, the multi-channel nature of 4D-STEM is essential to capture more of the information during dynamic processes. Aside from the advances of TEM instruments and analytical methods, more sophisticated micro-electro-mechanical devices (MEMS) have been incorporated into in-situ nano mechanical testing [54][55][56][57][58][59] , some of which have capabilities for applying and measuring fields along with mechanical load.…”

Piezoresistivity of InAsP Nanowires: Role of Crystal Phases and Phosphorus Atoms in Strain-Induced Channel Conductances

“…Among III-V semiconductor devices, nanowires particularly have obtained widespread interests as they generally have high mobility and direct band gap [6,7,8,9,10,11]. Additionally, III-V nanowires based on GaN [12], InAs [13,14], and InGaAs [15], show remarkable piezoresistive behaviors driven by tensile stress.…”