Core and Shell States of Silicon Nanowires under Strain

Abstract

The electronic structure characteristics of silicon nanowires under tensile and compressive strain are studied using first-principles density functional theory. The unique wirelike structure leads to distinct hole distributions in the core and shell regions, which can be characterized by the electronic band structures of the light-hole and heavy-hole states. The onset transition pressure for silicon nanowires is shown to be lower than the value of bulk counterpart, in conformity with experimental observations. These results demonstrate that the impact of strain on the electronic characteristics is important for nanodevice applications.

Tunable electronic properties of silicon nanowires under strain and electric bias

“…2, the effect of strain on the band gap is consistent with that of SiNWs along [111]. 15 With compressive and tensile strain, bands near the band edge L shift up and down, respectively. There is a notable change in the dispersion of the valence and conduction bands in the proximity of the point, resulting in a decrease of the effective mass for both compressive and tensile strain.…”

“…The impact of tensile and compressive strain on SiNWs is fundamentally important since the strain can yield nanostructures with novel properties, as nanomaterials respond to strain differently than their bulk counterparts. [15][16][17][18] A longitudinal electric bias modulates the band gap, while a transverse electric field leads to a transformation from an indirect band gap to a direct gap, making the NWs suitable for optoelectronic applications. 19 Despite intense studies of the effect of strain and the electric bias, this concerted effect is not well understood.…”

“…These results are similar to those of SiNWs along [111] directions where the light hole effective mass decreases under stress and increases when under tensile strain. 15 It is worth noting that the changes are greater for SiNWs along [110] than those in [111] direction.…”

“…In fact,the effect of a strain can be modeled as a linear potential γ R with γ being less and greater than zero for a contraction and extension, respectively. 15 For a SiNW under compression, the strain potential is minimum at the shell (γ < 0). Therefore, the charge density is localized at the shell for compressive strain.…”

Modulating the electronic structures and optical absorption spectra of BeO nanotubes by uniaxial strain

“…[1][2][3][4][5][6][7] For example, Logen and Peng have found the band gap and charge carries effective masses of Ge nanowires can be tuned easily by uniaxial strain. [1][2][3][4][5][6][7] For example, Logen and Peng have found the band gap and charge carries effective masses of Ge nanowires can be tuned easily by uniaxial strain.…”