Biaxial strain effects on photoluminescence of Ge/strained GeSn/Ge quantum well
Journal
Optical Materials Express
Journal Volume
8
Journal Issue
9
Pages
2795-2802
Date Issued
2018
Author(s)
Abstract
A Ge/GeSn/Ge single quantum well with 5% Sn content was grown by chemical vapor deposition on a Si substrate using Ge2H6 and SnCl4 precursors. External biaxial tensile strain was mechanically applied to the Ge/Ge0.95Sn0.05/Ge quantum well for the photoluminescence measurement. Note that the Ge0.95Sn0.05 layer is still under compressive strain due to the large internal compressive strain of the GeSn, although the external bending produces the tensile strain. The direct emission of tensily strained Ge buffer shifts toward lower energy, while the direct emission of pseudomorphic Ge0.95Sn0.05 quantum well does not have significant shift. The strain-induced energy changes of heavy holes and light holes in the Γ valley are extracted by fitting the photoluminescence spectra. Based on the nonlocal empirical pseudopotential method and the model-solid theory, a type-I band alignment is used for the fitting of photoluminescence spectra. The experimentally extracted band edge shifts from the photoluminescence measurement have good agreement with theoretical calculation. ? 2018 Optical Society of America.
Subjects
Chemical vapor deposition; Chlorine compounds; Photoluminescence; Semiconductor alloys; Tensile strain; Tin compounds; Biaxial strain effect; Biaxial tensile strain; Empirical pseudopotential method; Photoluminescence measurements; Photoluminescence spectrum; Single quantum well; Theoretical calculations; Type i band alignments; Semiconductor quantum wells
SDGs
Type
journal article