SiGeSn photonics at MIR wavelengths

Si-compatible photonic and opto-electronic devices operating at MIR wavelengths can now be fabricated using Sn-rich group IV semiconductor SiGeSn alloys, directly grown on a Si substrate. The possibility to independently engineer strain and composition in this new class of semiconductors allows for a high degree of tunability of band structure and lattice parameter of the material, thus enabling a variety of multi-layer heterostructures and low-dimensional systems. In this presentation, the recent progress in the non-equilibrium epitaxial growth of metastable (Si)GeSn semiconductors in a CVD reactor will be discussed.[1-2] Room-temperature Ge_0.83Sn_0.17 membrane photodetectors operating up to a wavelength of 4.6μm will be demonstrated, which lays the groundwork to implement scalable, flexible, and low-cost sensing and imaging technologies using Sn-rich group IV semiconductors.[3-4] This technology covers the MIR (3-8μm) that is commonly only accessible using expensive InSb and MCT materials. Moreover, the effect of material properties (crystalline quality, composition, point defects, dopants) will be discussed in MIR p-i-n photodetectors and LEDs.[1]S.Assali,Appl.Phys.Lett.251903(2018);[2]S.Assali,J.Appl.Phys.025304(2019);[3]M.Atalla,Adv.Func.Mat(2020);[4]S.Assali,arXiv:2004.13858