Tuning the Optoelectronic Properties of Capped Tensile-strained Ge Quantum Dots by Lattice Mismatch
Journal article, 2018

The optoelectronic properties of capped tensile-strained Ge quantum dot (QD) was studied with different lattice mismatch, which was formed by Ge and various substrate. The strain distribution of Ge QDs were simulated with the aid of finite element method (FEM) and the electronic structures of capped tensile-strained Ge QDs under such strain was calculated via deformation potential theory and effective mass approach (EMA). The size effect of Ge QDs was also considered. It was found that the capped QDs hold larger strain than the uncapped ones. In addition, the energy difference between Γ and L conduction valley reduced with the increase of the QD size and the lattice mismatch, thus converting the Ge QDs into the direct band gap material. The energy of the direct band gap decreased with the increase of the QDs' size. This work shows that the tensile-strained Ge QD is a promising light emission material for future optoelectronic applications such as lasers on Si.

Direct band gap

Tensile-strained Ge

Effective mass approach

Finite element method

Quantum dot

Author

Q. Chen

Chinese Academy of Sciences

Y Song

Chinese Academy of Sciences

Z. Zhang

Chinese Academy of Sciences

J. J. Liu

Chinese Academy of Sciences

P. F. Lu

Beijing University of Posts and Telecommunications (BUPT)

Y Li

Chinese Academy of Sciences

Shu Min Wang

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Chinese Academy of Sciences

Q Gong

Chinese Academy of Sciences

Cailiao Daobao/Materials Review

1005-023X (ISSN)

Vol. 32 3 1004-1009

Subject Categories

Other Materials Engineering

Composite Science and Engineering

Condensed Matter Physics

DOI

10.11896/j.issn.1005-023X.2018.06.028

More information

Latest update

3/18/2019