Modeling of the electronic band structure and the material gain in GeSn-based quantum wells

Abstract

In our recent work we have shown that the compressively stained GeSn/Ge quantum well (QW) is a very promising gain medium for lasers integrated with Si platform [1]. The material gain for such QW can be tuned in broad spectral range which is interesting for gas sensing [1]. Since Ge 1−w Sn w QW can be integrated with Si platform via Ge 1−z Sn z virtual substrate it is also possible to grown tensile strained Ge 1−w Sn w QWs when w 1−w Sn w /Si y Ge 1−x−y Sn x (QWs) with the strain changing from tensile (e = +1.5%) to compressive (e = −1.4%). It has been observed that the polarization degree can be tuned from 100% TE to 80% TM. In addition it is shown that SiyGe 1−x−y Sn x barriers lattice matched to the virtual Ge1-zSnz substrate (condition: y = 3.66(x-z)) ensure a good quantum confinement for electrons and holes in this material system. With such material features Ge 1−w Sn w /Si y Ge 1−x−y Sn x QW system integrated with Ge 1−z Sn z /Si platform is very perspective for light polarization engineering [2].