Grier, A, Valavanis, A, Cooper, JD et al. (3 more authors) Influence of barrier height on interface roughness scattering and coherent transport in AlGaAs quantum cascade lasers. In: UNSPECIFIED IQCLSW2014 International Quantum Cascade Lasers School and Workshop, 07-12 Sep 2014, Policoro, Italy. (Unpublished)
Abstract
Quantum cascade lasers (QCLs) are promising sources of terahertz (THz) radiation that have applications such as security and medical screening. While optical output power has recently exceeded 1 W, their highest operating temperature is currently limited to ~200 K due to mechanisms such as thermal back filling and non-radiative phonon emission between lasing states. Another possible cause of performance degradation is parasitic leakage currents over barriers into continuum states as subband electron temperatures increase with lattice temperature. Novel designs with new injection schemes remain an intensive research area and new efforts are being made assuming that barrier heights no longer need to be constant. A possible advantage of this is using tall barriers to reduce the leakage current, and in this work we present a theoretical study of the effects of increased barrier heights on transport between states in the structure. Similar to previous efforts, we initially restrict the modification of barrier height to the injection barrier; these are typically the thickest in THz QCLs and allow the reduced barrier widths necessary for AlAs barriers to remain above 1 ML.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Electronic & Electrical Engineering (Leeds) > Pollard Institute (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 23 Mar 2015 14:59 |
Last Modified: | 19 Dec 2022 13:30 |
Published Version: | http://www.iqclsw2014.cnr.it/ |
Status: | Unpublished |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:83311 |