Ion beam synthesis and photoluminescence study of supersaturated fully-relaxed Ge-Sn alloys
| Autor: | Quentin Hudspeth, James Williams, Tuan T. Tran, Lachlan A. Smillie, Yining Liu, Buguo Wang, Renaud A. Bruce, Jeffrey M. Warrender, Jay Mathews |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Photoluminescence Ion beam Band gap Alloy Analytical chemistry Silicon photonic materials 02 engineering and technology engineering.material 01 natural sciences Crystal 0103 physical sciences Ion-beam synthesis General Materials Science 010302 applied physics Germanium-tin alloys Supersaturated doping Mechanical Engineering equipment and supplies 021001 nanoscience & nanotechnology Condensed Matter Physics Non-equilibrium annealing Ion implantation Mechanics of Materials engineering Relaxation (physics) Direct and indirect band gaps 0210 nano-technology Den kondenserade materiens fysik |
| Popis: | Direct-bandgap germanium-tin (Ge-Sn) alloys are highly sought-after materials for applications in silicon photonic integrated circuits. Other than crystal quality, two main factors determine the transition from the indirect to direct bandgap: the high Sn concentration and the strain relaxation in the materials. Using ion implantation and pulsed laser melting, we demonstrate a fully-relaxed Ge-Sn alloy with a Sn concentration of 6 a t . % . This concentration is at least 10 times higher than the equilibrium solubility of Sn in Ge. Cross-sectional transmission electron microscopy shows unconventional threading-like defects in the film as the mechanism for the strain relaxation. Due to the high degree of strain relaxation and the good crystal quality, photoluminescence could be obtained from the samples to examine the indirect-direct bandgap transition in the alloys. |
| Databáze: | OpenAIRE |
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