
**(Si)GeSn Semiconductors for integrated optoelectronics and quantum
electronics**
Simone Assali
Ecole Polytechnique de Montreal, Canada
Nanoscale heterostructures and low-dimensional systems enable a precise and
simultaneous control of lattice parameter and band gap in conventional III-V
semiconductors. Extending this paradigm to group-IV semiconductors will pave
the way in creating an entirely new class of scalable photonic,
optoelectronic, and quantum devices on a Silicon substrate. Major improvements
in the fabrication of a fully-group IV integrated photonic platform were
recently achieved with the development of Germanium-Tin (GeSn) alloys.[1] In
this material system, efficient light absorption and emission at infrared
wavelengths (above 2.0 μm) is obtained when increasing the Sn incorporation
above 10 at.%. The ability to incorporate Sn atoms in Ge at concentrations
about one order of magnitude higher than the 1 at.% equilibrium solubility is
at the core of these emerging technologies.
In this presentation, the recent progress in the epitaxial growth and
optoelectronic properties of GeSn low-dimensional systems will be discussed
from the macroscopic level down to the atomic scale in nanowires[2-3] and thin
film[4-5] heterostructures. The relevance of these semiconductors for the
development of room-temperature optical communication, sensing, and imaging
technologies operating at infrared wavelengths will be discussed form both
materials and device perspectives. Moreover, the possibility to implement
novel scalable quantum devices using group-IV semiconductors will be
addressed, paving the way to manipulate spin along with coherent optical
transition in spin qubits.[6]
**References **
[1] O. Moutanabbir et al., Monolithic Infrared Silicon Photonics: The Rise of
(Si)GeSn Semiconductors, Appl. Phys. Lett., 118, 110502 (2021).
[2] S. Assali et al., Growth and Optical Properties of Direct Band Gap
Ge/Ge0.87Sn0.13 Core/Shell Nanowire Arrays, Nano Letters 17 (3), 1538–1544
(2017).
[3] L. Luo et al., Highly Responsive Extended-SWIR Photodetection in All-Group
IV Core/Shell Nanowires, ACS Photonics 9 (3), 914-921 (2022).
[4] S. Assali et al., Atomically uniform Sn-rich GeSn semiconductors with
3.0-3.5 μm room-temperature optical emission, Appl. Phys. Lett. 112, 251903
(2018).
[5] M.R.M. Atalla et al., High-Bandwidth Extended-SWIR GeSn Photodetectors on
Silicon Achieving Ultrafast Broadband Spectroscopic Response, ACS Photonics, 9
(4), 1425–1433 (2022).
[6] S. Assali et al., A Light-Hole Germanium Quantum Well on Silicon,
arXiv:2112.15185.
**Host:** J. M. Pitarke