Article ID Journal Published Year Pages File Type
748184 Solid-State Electronics 2013 10 Pages PDF
Abstract

•Strain effect on electrical conductivity of Si/SiGe nano thin films is investigated.•A modeling approach for the strain effect analysis is presented.•1% External strain can cause a change of up to 40% in the electrical conductivity.•The observed strain effect is explained through detailed subband calculations.

In this work, the effect of various externally applied strains on the electrical conductivity of Si/Si1−xGex nanocomposite thin films is studied. A degenerate two-band k ⋅ p theory is utilized to calculate the variation of the electronic band structure in the semiconductor nanocomposite thin films as a function of externally applied strains. The strain-dependent electrical conductivity of the material is computed by using a two dimensional real-space Non-Equilibrium Green’s Function (NEGF) self-consistently coupled with the Poisson equation. In the analysis, [1 0 0] uniaxial, [1 0 0]/[0 0 1] and [1 0 0]/[0 1 0] biaxial strains are considered for the through-thickness electron transport in [1 0 0] direction. Numerical results demonstrate that the external strains have a significant influence on the electrical conductivity of the nanocomposite thin films. We show that the electrical conductivity variation can be attributed to combined effects of strain-induced splitting of the conduction band edges and change in band offset, electron quantum confinement, and size of the inclusion material in the thin films.

Related Topics
Physical Sciences and Engineering Engineering Electrical and Electronic Engineering
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