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

In Kim,Han Seul Kim,Hoon Ryu

doi:10.3390/molecules24183249

In Kim, Han Seul Kim + Show 1 more

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https://doi.org/10.3390/molecules24183249

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Abstract

Strong piezoresistivity of InAsP nanowires is rationalized with atomistic simulations coupled to Density Functional Theory. With a focal interest in the case of the As(75%)-P(25%) alloy, the role of crystal phases and phosphorus atoms in strain-driven carrier conductance is discussed with a direct comparison to nanowires of a single crystal phase and a binary (InAs) alloy. Our analysis of electronic structures presents solid evidences that the strong electron conductance and its sensitivity to external tensile stress are due to the phosphorous atoms in a Wurtzite phase, and the effect of a Zincblende phase is not remarkable. With several solid connections to recent experimental studies, this work can serve as a sound framework for understanding of the unique piezoresistive characteristics of InAsP nanowires.

Highlights

Piezoelectric and piezoresistive effects, the capability of converting mechanical stress to electrical signals, induced much intention as a novel candidate of nanoscale sensors for detection of small forces or pressures [1,2,3,4] owing to their special characteristics that enable uncomplicated device designs with relatively low power consumption in operations [5]
It has been found that InAsP nanowires, which have two crystal phase of a Wurtzite (WZ) and Zincblende (ZB), possess piezoresistivity [16]
In-depth analysis on piezoresistive behaviors of InAsP nanowires is conducted with aids of simulations based on Density Functional Theory

Summary

Introduction

Piezoelectric and piezoresistive effects, the capability of converting mechanical stress to electrical signals, induced much intention as a novel candidate of nanoscale sensors for detection of small forces or pressures [1,2,3,4] owing to their special characteristics that enable uncomplicated device designs with relatively low power consumption in operations [5]. Among III-V semiconductor devices, nanowires have obtained widespread interests as they generally have high mobility and direct band gap [6,7,8,9,10,11]. A following theory theoretically predicted this phenomenon may be due to the increase of mobility coming from strain-induced reduction of band gap energies in nanowires of a WZ phase [17]. The prediction is, deduced only with investigation of a single WZ configuration so its comparison to a ZB phase is not clear. Another theory work on InAs systems reported the enhancement of carrier transport is mainly due to a WZ phase [18]

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