Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers
Abstract In this work, we investigate the effects of n and p-type background doping, interface composition diffusion (interdiffusion) of the barrier material and layer thickness variation during molecular beam epitaxy (MBE) growth on transport characteristics of terahertz-frequency quantum cascade l...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2024-03-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-024-55700-7 |
| _version_ | 1797266859018420224 |
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| author | Novak Stanojević Aleksandar Demić Nikola Vuković Paul Dean Zoran Ikonić Dragan Indjin Jelena Radovanović |
| author_facet | Novak Stanojević Aleksandar Demić Nikola Vuković Paul Dean Zoran Ikonić Dragan Indjin Jelena Radovanović |
| author_sort | Novak Stanojević |
| collection | DOAJ |
| description | Abstract In this work, we investigate the effects of n and p-type background doping, interface composition diffusion (interdiffusion) of the barrier material and layer thickness variation during molecular beam epitaxy (MBE) growth on transport characteristics of terahertz-frequency quantum cascade lasers (THz QCLs). We analysed four exemplary structures: a bound-to-continuum design, hybrid design, LO-phonon design and a two-well high-temperature performance LO-phonon design. The exemplary bound-to-continuum design has shown to be the most sensitive to the background doping as it stops lasing for concentrations around $$1.0\cdot 10^{15}$$ 1.0 · 10 15 – $$2.0\cdot 10^{15}$$ 2.0 · 10 15 cm $$^{-3}$$ - 3 . The LO-phonon design is the most sensitive to growth fluctuations during MBE and this is critical for novel LO-phonon structures optimised for high-temperature performance. We predict that interdiffusion mostly affects current density for designs with narrow barrier layers and higher $$\textrm{Al}$$ Al composition. We show that layer thickness variation leads to significant changes in material gain and current density, and in some cases to the growth of nonfunctional devices. These effects serve as a beacon of fundamental calibration steps required for successful realisation of THz QCLs. |
| first_indexed | 2024-04-25T01:07:23Z |
| format | Article |
| id | doaj.art-a9129d27a7f94961821d8b0638fd5a4a |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-25T01:07:23Z |
| publishDate | 2024-03-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-a9129d27a7f94961821d8b0638fd5a4a2024-03-10T12:11:50ZengNature PortfolioScientific Reports2045-23222024-03-0114111310.1038/s41598-024-55700-7Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasersNovak Stanojević0Aleksandar Demić1Nikola Vuković2Paul Dean3Zoran Ikonić4Dragan Indjin5Jelena Radovanović6School of Electrical Engineering, University of BelgradeSchool of Electronic and Electrical Engineering, University of LeedsSchool of Electrical Engineering, University of BelgradeSchool of Electronic and Electrical Engineering, University of LeedsSchool of Electronic and Electrical Engineering, University of LeedsSchool of Electronic and Electrical Engineering, University of LeedsSchool of Electrical Engineering, University of BelgradeAbstract In this work, we investigate the effects of n and p-type background doping, interface composition diffusion (interdiffusion) of the barrier material and layer thickness variation during molecular beam epitaxy (MBE) growth on transport characteristics of terahertz-frequency quantum cascade lasers (THz QCLs). We analysed four exemplary structures: a bound-to-continuum design, hybrid design, LO-phonon design and a two-well high-temperature performance LO-phonon design. The exemplary bound-to-continuum design has shown to be the most sensitive to the background doping as it stops lasing for concentrations around $$1.0\cdot 10^{15}$$ 1.0 · 10 15 – $$2.0\cdot 10^{15}$$ 2.0 · 10 15 cm $$^{-3}$$ - 3 . The LO-phonon design is the most sensitive to growth fluctuations during MBE and this is critical for novel LO-phonon structures optimised for high-temperature performance. We predict that interdiffusion mostly affects current density for designs with narrow barrier layers and higher $$\textrm{Al}$$ Al composition. We show that layer thickness variation leads to significant changes in material gain and current density, and in some cases to the growth of nonfunctional devices. These effects serve as a beacon of fundamental calibration steps required for successful realisation of THz QCLs.https://doi.org/10.1038/s41598-024-55700-7 |
| spellingShingle | Novak Stanojević Aleksandar Demić Nikola Vuković Paul Dean Zoran Ikonić Dragan Indjin Jelena Radovanović Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers Scientific Reports |
| title | Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers |
| title_full | Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers |
| title_fullStr | Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers |
| title_full_unstemmed | Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers |
| title_short | Effects of background doping, interdiffusion and layer thickness fluctuation on the transport characteristics of THz quantum cascade lasers |
| title_sort | effects of background doping interdiffusion and layer thickness fluctuation on the transport characteristics of thz quantum cascade lasers |
| url | https://doi.org/10.1038/s41598-024-55700-7 |
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