Theoretical Investigation of Biaxially Tensile-Strained Germanium Nanowires
Artikel i vetenskaplig tidskrift, 2017

We theoretically investigate highly tensile-strained Ge nanowires laterally on GaSb. Finite element method has been used to simulate the residual elastic strain in the Ge nanowire. The total energy increment including strain energy, surface energy, and edge energy before and after Ge deposition is calculated in different situations. The result indicates that the Ge nanowire on GaSb is apt to grow along < 100 > rather than < 110 > in the two situations and prefers to be exposed by {105} facets when deposited a small amount of Ge but to be exposed by {110} when the amount of Ge exceeds a critical value. Furthermore, the conduction band minima in Gamma-valley at any position in both situations exhibits lower values than those in L-valley, leading to direct bandgap transition in Ge nanowire. For the valence band, the light hole band maxima at Gamma-point is higher than the heavy hole band maxima at any position and even higher than the conduction band minima for the hydrostatic strain more than similar to 5.0%, leading to a negative bandgap. In addition, both electron and hole mobility can be enhanced by owing to the decrease of the effective mass under highly tensile strain. The results suggest that biaxially tensile-strained Ge nanowires hold promising properties in device applications.

field-effect transistors

si

surface-energy

ge nanowires

light-emission

growth

heterostructures

quantum dots

Författare

Z. Y. S. Zhu

ShanghaiTech University

Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

yuxin song

Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

Q Chen

Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

Chinese Academy of Sciences

Z. Zhang

Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

ShanghaiTech University

Liyao Zhang

Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

Yaoyao Li

Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences

Shu Min Wang

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

Nanoscale Research Letters

1931-7573 (ISSN) 1556-276X (eISSN)

Vol. 12 Article no 472 - 472

Ämneskategorier

Nanoteknik

DOI

10.1186/s11671-017-2243-1