Journal
ACS PHOTONICS
Volume 2, Issue 11, Pages 1539-1545Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acsphotonics.5b00372
Keywords
direct bandgap; photoluminescence; germanium tin; group IV; compressive strain
Categories
Funding
- Federal Ministery of Education and Research (BMBF) [16ES0060 K]
Ask authors/readers for more resources
A comprehensive study of optical transitions in direct-bandgap Ge0.875Sn0.125 group IV alloys via photo-luminescence measurements as a function of temperature, compressive strain and excitation power is performed. The analysis of the integrated emission intensities reveals a strain-dependent indirect-to-direct bandgap transition, in good agreement with band structure calculations based on the 8-band k.p and deformation potential methods. We have observed and quantified Gamma valley-heavy hole and Gamma valley-light hole transitions at low pumping power and low temperatures in order to verify the splitting of the valence band due to strain. We will demonstrate that the intensity evolution of these transitions supports the conclusion about the fundamental direct bandgap in compressively strained GeSn alloys. The presented investigation, thus, demonstrates that direct-bandgap group IV alloys can be directly grown on Ge-buffered Si(001) substrates despite their residual compressive strain.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available