Analysis of Raman scattering from inclined GeSn/Ge dual-nanowire heterostructure on Ge(1 1 1) substrate
Artikel i vetenskaplig tidskrift, 2019

In this paper, the Raman spectra of GeSn/Ge dual-nanowire heterostructure grown on Ge(1 1 1) substrate are systematically analyzed within the framework of anisotropic elasticity and lattice dynamical theory. Based on the experimental samples grown by molecular beam epitaxy, the partially covered dual nanowires standing along 〈1 1 0〉 direction are modeled and the heterostructure presents effective elastic strain relaxation due to the free surfaces. The simulations show that the Raman shift of GeSn nanowire is mainly affected by the Sn content while the influences of strain become less important with the increase of thickness ratio. For Ge nanowire, the peak of Raman spectrum merely moves with Sn content, but the spectrum possesses asymmetric broadening induced by the non-uniform strain distribution. The red-shift and intensity reduction of the total Raman spectrum of dual nanowires are observed when the Sn content increases. Moreover, an analytic fitting expression for Raman peak position is obtained based on the numerical results and is expected to serve as a reference to estimate the Sn content in GeSn/Ge dual-nanowire heterostructure.

Dual-nanowire heterostructure

Strain relaxation

Raman scattering

GeSn alloy

Författare

Delong Han

Beijing University of Posts and Telecommunications (BUPT)

Han Ye

Beijing University of Posts and Telecommunications (BUPT)

Y Song

Chinese Academy of Sciences

Z. Y. S. Zhu

Chinese Academy of Sciences

Yuekun Yang

Chinese Academy of Sciences

Z. Y. Yu

Beijing University of Posts and Telecommunications (BUPT)

Yumin Liu

Beijing University of Posts and Telecommunications (BUPT)

Shu Min Wang

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

Chinese Academy of Sciences

Zengfeng Di

Chinese Academy of Sciences

Applied Surface Science

0169-4332 (ISSN)

Vol. 463 581-586

Ämneskategorier

Teknisk mekanik

Annan materialteknik

Den kondenserade materiens fysik

DOI

10.1016/j.apsusc.2018.08.207

Mer information

Senast uppdaterat

2018-09-13