Abnormal strain in suspended GeSn microstructures
Artikel i vetenskaplig tidskrift, 2018

A suspended GeSn microstructure is realized by a two-step selective wet etching technique with the aim of fully relaxing the compressive strain, promoting the indirect to direct bandgap transition and improving the optical property of GeSn thin films grown on Ge. The compressive strain was found efficiently relaxed, and even unexpected large tensile strain was displayed on regions of the microstructure by micro-Raman spectroscopy. Residual Ge patches under the suspended GeSn microstructure were found by scanning electron microscopy and proved to be the origin of the tensile strain by finite element method simulations. The tensile strain on the surface is beneficial for direct bandgap conversion and carrier accumulation. Significant enhancement of photoluminescence was obtained in the GeSn microstructures than the original thin film.

strain engineering

GeSn

microstructure

FEM

silicon photonics

mu-Raman

PL

Författare

Yi Han

Chinese Academy of Sciences

Univ Chinese Acad Sci

Yuxin Song

Chinese Academy of Sciences

Xiren Chen

Chinese Academy of Sciences

Zhenpu Zhang

Chinese Academy of Sciences

ShanghaiTech University

Juanjuan Liu

Chinese Academy of Sciences

Yaoyao Li

Chinese Academy of Sciences

Zhongyunshen Zhu

Chinese Academy of Sciences

ShanghaiTech University

Hua Huang

Chinese Academy of Sciences

Jun Shao

Chinese Academy of Sciences

Shu Min Wang

Chalmers, Mikroteknologi och nanovetenskap (MC2), Fotonik

Materials Research Express

2053-1591 (eISSN)

Vol. 5 035901

Ämneskategorier

Materialkemi

Annan materialteknik

Den kondenserade materiens fysik

DOI

10.1088/2053-1591/aaafec