Journal ArticleDOI
Increased photoluminescence of strain-reduced, high-Sn composition Ge1−xSnx alloys grown by molecular beam epitaxy
TLDR
In this paper, the authors synthesize up to Ge0.914Sn0.086 alloys on (100) GaAs/InyGa1−yAs buffer layers using molecular beam epitaxy.Abstract:
We synthesized up to Ge0.914Sn0.086 alloys on (100) GaAs/InyGa1−yAs buffer layers using molecular beam epitaxy. The buffer layers enable engineered control of strain in the Ge1−xSnx layers to reduce strain-related defects and precipitation. Samples grown under similar conditions show a monotonic increase in the integrated photoluminescence (PL) intensity as the Sn composition is increased, indicating changes in the bandstructure favorable for optoelectronics. We account for bandgap changes from strain and composition to determine a direct bandgap bowing parameter of b = 2.1 ± 0.1. According to our models, these are the first Ge1−xSnx samples that are both direct-bandgap and exhibit PL.read more
Citations
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Journal ArticleDOI
Lasing in direct-bandgap GeSn alloy grown on Si
Stephan Wirths,R. Geiger,R. Geiger,N. von den Driesch,Gregor Mussler,Toma Stoica,Siegfried Mantl,Zoran Ikonic,Martina Luysberg,Stefano Chiussi,J. M. Hartmann,Hans Sigg,Jérôme Faist,Dan Buca,Detlev Grützmacher +14 more
TL;DR: In this paper, a direct bandgap GeSn alloy, grown directly onto Si(001), was used for experimentally demonstrating lasing threshold and linewidth narrowing at low temperatures.
Journal ArticleDOI
On-chip light sources for silicon photonics
TL;DR: Zhou et al. as discussed by the authors assess the three main contenders for on-chip light sources: erbium-based light sources, germanium-on-silicon lasers and III-V-based silicon lasers.
Journal ArticleDOI
Achieving direct band gap in germanium through integration of Sn alloying and external strain
TL;DR: In this paper, a theoretical model was developed based on the nonlocal empirical pseudopotential method to determine the electronic band structure of germanium tin (GeSn) alloys, and modifications to the virtual crystal potential accounting for disorder induced potential fluctuations were incorporated to reproduce the large direct band gap bowing observed in GeSn alloys.
Journal ArticleDOI
Electronic band structure and effective mass parameters of Ge1-xSnx alloys
TL;DR: In this article, the electronic band structures of bulk Ge1-xSnx alloys were investigated using the empirical pseudopotential method (EPM) for Sn composition x varying from 0 to 0.2.
Journal ArticleDOI
Si–Ge–Sn alloys: From growth to applications
Stephan Wirths,Dan Buca,S. Mantl +2 more
TL;DR: In this paper, the transition from an indirect to a fundamental direct bandgap material will be discussed, and the most commonly used approaches, i.e., molecular beam epitaxy (MBE) and chemical vapor deposition (CVD), will be reviewed in terms of crucial process parameters, structural as well as optical quality and employed precursor combinations including Germanium hydrides, Silicon hydride and a variety of Sn compounds like SnD4, SnCl4 or C6H5SnD3.
References
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Journal ArticleDOI
Interband Transitions in Sn x Ge 1-x Alloys
Gang He,Harry A. Atwater +1 more
TL;DR: Optical absorption measurements for diamond cubic cubic alloy films indicate strong interband transitions with a change in direct energy gap of $0.35l{E}_{g}l0.80\mathrm{eV}$ for $ 0.15gxg0$.
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Optical critical points of thin-film Ge 1-y Sn y alloys: A comparative Ge 1-y Sn y /Ge 1-x Si x study
V. R. D'Costa,Candi S. Cook,A. G. Birdwell,Chris L. Littler,Michael Canonico,Stefan Zollner,John Kouvetakis,Jose Menendez +7 more
TL;DR: In this paper, a scaling behavior for the electronic properties that is the analog of the scaling behavior found earlier for the vibrational properties was found for the optical transitions in the alloys, which is not predicted by electronic structure calculations within the virtual crystal approximation.
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Direct-gap photoluminescence with tunable emission wavelength in Ge1−ySny alloys on silicon
TL;DR: In this paper, direct-gap photoluminescence has been observed at room temperature in Ge1−ySny alloys grown on (001) Si substrates.
Journal ArticleDOI
Origin of the unusually large band-gap bowing and the breakdown of the band-edge distribution rule in the Sn x Ge 1-x alloys
TL;DR: In this paper, the unusual nonlinear behaviors of the band gaps in alloys are investigated using first-principles calculations, and it is shown that the large bowing of the direct band gap is induced by the disordering effect.
Journal ArticleDOI
Strong enhancement of direct transition photoluminescence with highly tensile-strained Ge grown by molecular beam epitaxy
Yijie Huo,Hai Lin,Robert Chen,Maria Makarova,Yiwen Rong,Mingyang Li,Theodore I. Kamins,Jelena Vuckovic,James S. Harris +8 more
TL;DR: In this article, high tensile-strained layers of Ge were grown via molecular beam epitaxy using step-graded InxGa1−xAs buffer layers on (100) GaAs.