Midinfrared Emission and Absorption in Strained and Relaxed Direct-Band-Gap Ge1−xSnx Semiconductors
| Autor: | Étienne Bouthillier, Jos E. M. Haverkort, Alain Dijkstra, Oussama Moutanabbir, Anis Attiaoui, Simone Assali |
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| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science Photoluminescence Silicon business.industry Relaxation (NMR) General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Atmospheric temperature range 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics Condensed Matter::Materials Science Semiconductor chemistry 0103 physical sciences Content (measure theory) Direct and indirect band gaps Absorption (logic) 0210 nano-technology business |
| Zdroj: | Physical Review Applied. 15 |
| ISSN: | 2331-7019 |
| Popis: | By independently engineering strain and composition, this work demonstrates and investigates direct-band-gap emission in the midinfrared range from ${\mathrm{Ge}}_{1\text{\ensuremath{-}}x}{\mathrm{Sn}}_{x}$ layers grown on silicon. We extend the room-temperature emission wavelength above approximately 4.0 \textmu{}m upon postgrowth strain relaxation in layers with uniform Sn content of 17 at.%. The fundamental mechanisms governing the optical emission are discussed based on temperature-dependent photoluminescence, absorption measurements, and theoretical simulations. Regardless of strain and composition, these analyses confirm that single-peak emission is always observed in the probed temperature range of 4--300 K, ruling out defect- and impurity-related emission. Moreover, carrier losses into thermally activated nonradiative recombination channels are found to be greatly minimized as a result of strain relaxation. Absorption measurements validate the direct band-gap in strained and relaxed samples at energies closely matching photoluminescence data. These results highlight the strong potential of ${\mathrm{Ge}}_{1\text{\ensuremath{-}}x}{\mathrm{Sn}}_{x}$ semiconductors as versatile building blocks for scalable, compact, and silicon-compatible midinfrared photonics and quantum optoelectronics. |
| Databáze: | OpenAIRE |
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