THz intersubband electroluminescence from n-type Ge/SiGe quantum cascade structures
Abstract
© 2021 Author(s). We report electroluminescence originating from L-valley transitions in n-type Ge/Si0.15Ge0.85 quantum cascade structures centered at 3.4 and 4.9 THz with a line broadening of Δ f / f ≈ 0.2. Three strain-compensated heterostructures, grown on a Si substrate by ultrahigh vacuum chemical vapor deposition, have been investigated. The design is based on a single quantum well active region employing a vertical optical transition, and the observed spectral features are well described by non-equilibrium Green's function calculations. The presence of two peaks highlights a suboptimal injection in the upper state of the radiative transition. Comparison of the electroluminescence spectra with a similar GaAs/AlGaAs structure yields one order of magnitude lower emission efficiency. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000475415Publication status
publishedExternal links
Journal / series
Applied Physics LettersVolume
Pages / Article No.
Publisher
American Institute of PhysicsOrganisational unit
02510 - Institut für Quantenelektronik / Institute for Quantum Electronics02010 - Dep. Physik / Dep. of Physics
03759 - Faist, Jérôme / Faist, Jérôme
02205 - FIRST-Lab / FIRST Center for Micro- and Nanoscience
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