Room temperature optically pumped GeSn microdisk lasers

GeSn alloys are promising materials for light emitters monolithically grown on silicon. In this work, we demonstrate room temperature (RT) lasing in a GeSn hetero-structure with 17.2% of Sn. We report a threshold of $3.27 MW cm−2$ at 305 K with peak emission at 353 meV. We ascribe these improvements to a higher tin concentration in the GeSn active layer with lower Sn content barriers on each side and to a better thermal dissipation provided by an adapted pedestal architecture beneath the GeSn micro-disk. This outcome is a major milestone for a fully integrated group-IV semiconductor laser on Si.