Moderate bending strain induced semiconductor to metal transition in Si nanowires

TL;DR

This study demonstrates that moderate bending strains (~3%) can induce a semiconductor-to-metal transition in silicon nanowires of 1-4.3 nm diameter, with wider nanowires transitioning at lower strains, highlighting bending as an efficient strain method.

Contribution

The paper reveals that bending strain is more effective than uniaxial strain in inducing semiconductor-metal transitions in silicon nanowires, supported by molecular dynamics and quantum transport simulations.

Findings

Wider nanowires undergo transition at lower bending strains.

Bending strain enhances electronic transport more effectively than uniaxial strain.

Moderate bending (~3%) can induce a transition in nanowires of ~4 nm diameter.

Abstract

Moderate amount of bending strains, ~3% are enough to induce the semiconductor-metal transition in Si nanowires of ~4nm diameter. The influence of bending on silicon nanowires of 1 nm to 4.3 nm diameter is investigated using molecular dynamics and quantum transport simulations. Local strains in nanowires are analyzed along with the effect of bending strain and nanowire diameter on electronic transport and the transmission energy gap. Interestingly, relatively wider nanowires are found to undergo semiconductor-metal transition at relatively lower bending strains. The effect of bending strain on electronic properties is then compared with the conventional way of straining, i.e. uniaxial, which shows that, the bending is much more efficient way of straining to enhance the electronic transport and also to induce the semiconductor-metal transition in experimentally realizable Si nanowires.