Ge1-xSnx epitaxial heterostructures are emerging as prominent candidates for the monolithic integration of light sources on Si substrates. Here we propose a suitable explanation for their temperature-dependent photoluminescence (PL) that is based upon the so far disregarded optical activity of dislocations. By working at the onset of plastic relaxation, which occurs whenever the epilayer releases the strain accumulated during growth on the lattice-mismatched substrate, we demonstrate that dislocation nucleation can be explicitly seen in the PL data. Notably, our findings point out that a monotonic thermal PL quenching can be observed in coherent films, in spite of the indirect nature of the Ge1-xSnx band-gap. Our investigation, therefore, contributes to a deeper understanding of the recombination dynamics in this intriguing group IV alloy and offers insights into crucial phenomena shaping the light emission efficiency.

Pezzoli, F., Giorgioni, A., Patchett, D., Myronov, M. (2016). Temperature-Dependent Photoluminescence Characteristics of GeSn Epitaxial Layers. ACS PHOTONICS, 3(11), 2004-2009 [10.1021/acsphotonics.6b00438].

Temperature-Dependent Photoluminescence Characteristics of GeSn Epitaxial Layers

PEZZOLI, FABIO
Primo
;
GIORGIONI, ANNA
Secondo
;
2016

Abstract

Ge1-xSnx epitaxial heterostructures are emerging as prominent candidates for the monolithic integration of light sources on Si substrates. Here we propose a suitable explanation for their temperature-dependent photoluminescence (PL) that is based upon the so far disregarded optical activity of dislocations. By working at the onset of plastic relaxation, which occurs whenever the epilayer releases the strain accumulated during growth on the lattice-mismatched substrate, we demonstrate that dislocation nucleation can be explicitly seen in the PL data. Notably, our findings point out that a monotonic thermal PL quenching can be observed in coherent films, in spite of the indirect nature of the Ge1-xSnx band-gap. Our investigation, therefore, contributes to a deeper understanding of the recombination dynamics in this intriguing group IV alloy and offers insights into crucial phenomena shaping the light emission efficiency.
Lettera in rivista
dislocations; germanium; GeSn; photoluminescence; RP-CVD; strain; Electronic, Optical and Magnetic Materials; Atomic and Molecular Physics, and Optics; Electrical and Electronic Engineering
English
2016
3
11
2004
2009
partially_open
Pezzoli, F., Giorgioni, A., Patchett, D., Myronov, M. (2016). Temperature-Dependent Photoluminescence Characteristics of GeSn Epitaxial Layers. ACS PHOTONICS, 3(11), 2004-2009 [10.1021/acsphotonics.6b00438].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/149467
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