On giant piezoresistance effects in silicon nanowires and microwires

TL;DR

This study investigates the giant piezoresistance effects in silicon nanowires and microwires, revealing that surface trapping causes apparent effects, but the true PZR is comparable to bulk silicon.

Contribution

The paper demonstrates that surface trapping effects can mimic giant PZR in silicon nanostructures, clarifying the true magnitude of PZR in these materials.

Findings

Surface trapping causes time-dependent resistance changes.

Apparent giant PZR is due to surface effects, not intrinsic properties.

True PZR in nanostructures is similar to bulk silicon.

Abstract

The giant piezoresistance (PZR) previously reported in silicon nanowires is experimentally investigated in a large number of surface depleted silicon nano- and micro-structures. The resistance is shown to vary strongly with time due to electron and hole trapping at the sample surfaces. Importantly, this time varying resistance manifests itself as an apparent giant PZR identical to that reported elsewhere. By modulating the applied stress in time, the true PZR of the structures is found to be comparable with that of bulk silicon.