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Germanium laser on silicon contacts could become more stable
(c) CEA-Leti
Published on 21 April 2021
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Optronics researchers love the idea of germanium lasers on silicon but the devices' contacts are highly thermally unstable. In a world-first, a PhD research project being conducted at CEA-Leti has explained this unpredictable behavior. PhD candidate Andrea Quintero has published ten papers on the phenomenon over the past three years, even winning a Best Paper Award at ECS Prime 2020.
Germanium is an indirect gap material, so it must have tin content of 10% or 15% to deliver the desired optical performance. However, a heating process used to fabricate the contacts exposes them to temperatures that cause tin segregation. Andrea utilized several pieces of equipment at the Nanocharacterization Platform (PFNC) to observe and formally describe the diffusion of tin towards the surface of the material.
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