Highly Tensile-Strained Self-Assembled Ge Quantum Dots on InP Substrates for Integrated Light Sources
Artikel i vetenskaplig tidskrift, 2021

Highly tensile-strained Ge quantum dots (TS-Ge-QDs) emitting structures with different size were successfully grown on InP substrates by molecular beam epitaxy. Dislocation-free TS-Ge-QDs were observed by transmission electron microscopy. Finite element modeling indicates a maximum tensile strain of 4.5% in the Ge QDs, which is much larger than the required strain to achieve direct band gap conversion of Ge based on theoretical prediction. Photoluminescence (PL) from a direct band-gap-like transition of TS-Ge-QDs with a peak energy of 0.796 eV was achieved and confirmed by the etch depth-dependent PL, temperature-dependent PL, and excitation-power-dependent PL. In addition, a strong defect-related peak of 1 eV was observed at room temperature. The band structure of the TS-Ge-QDs emitting structures was calculated to support the experimental results of PL spectra. Achieving PL from direct band-gap-like transitions of TS-Ge-QDs provides encouraging evidence of this promising highly tensile strained semiconductor-nanostructure-based platform for future photonics applications such as integrated light sources.

quantum dots


tensile strain

quantum confinement effects

self-assembled growth



Q. Chen

Chinese Academy of Sciences

Nanyang Technological University

Liyao Zhang

University of Shanghai for Science and Technology

Y Song

Chinese Academy of Sciences

X Chen

Chinese Academy of Sciences

Sebastian Koelling

Technische Universiteit Eindhoven

Z. Zhang

Chinese Academy of Sciences

Y Li

Chinese Academy of Sciences

P. M. Koenraad

Technische Universiteit Eindhoven

Jun Shao

Chinese Academy of Sciences

Chuan Seng Tan

Nanyang Technological University

Shu Min Wang

Chalmers, Mikroteknologi och nanovetenskap, Fotonik

Chinese Academy of Sciences

Qian Gong

Chinese Academy of Sciences

ACS Applied Nano Materials

25740970 (eISSN)

Vol. 4 1 897-906


Atom- och molekylfysik och optik


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