Numerical analysis of inter-valley electrons transferring behavior in GeSn alloys for optoelectronic applications

The electron-phonon interaction in GeSn alloys provides a handle to tune its optoelectronic properties for a variety of applications. A comprehensive understanding of how the inter-valley scattering between Γ and L valleys modulates electron dynamics in GeSn alloys is needed. This letter focuses on the theoretical analysis of inter-valley scattering mechanisms between Γ and L valleys, and hence on the electron transmission dynamics in GeSn alloys. Firstly, the electronic band structure of GeSn alloys in the full Brillouin zone has been reproduced by 30-band k•p method. Secondly, inter-valley scattering calculations have been shown that scattering rate of electrons from Γ valley to L valley is higher than that from L valley to Γ valley. Thirdly, electron transmission dynamics indicates that inter-valley scattering help to enhance the electron population in Γ valley for GeSn materials with low Sn composition. Results are beneficial to understand the microscopic mechanism of carrier scattering in GeSn materials and can be a potential theoretical approach for optimizing the performance of GeSn-based optoelectronic devices.