Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes
The time dynamics of nonequilibrium charge carrier relaxation processes in SI GaAs:EL2 (semi-insulating gallium arsenide compensated with EL2 centers) and HR GaAs:Cr (high-resistive gallium arsenide compensated with chromium) were studied by the optical pump–terahertz probe technique. Charge carrier...
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MDPI AG
2021-12-01
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| Series: | Photonics |
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| Online Access: | https://www.mdpi.com/2304-6732/8/12/575 |
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| author | Irina A. Kolesnikova Daniil A. Kobtsev Ruslan A. Redkin Vladimir I. Voevodin Anton V. Tyazhev Oleg P. Tolbanov Yury S. Sarkisov Sergey Yu. Sarkisov Victor V. Atuchin |
| author_facet | Irina A. Kolesnikova Daniil A. Kobtsev Ruslan A. Redkin Vladimir I. Voevodin Anton V. Tyazhev Oleg P. Tolbanov Yury S. Sarkisov Sergey Yu. Sarkisov Victor V. Atuchin |
| author_sort | Irina A. Kolesnikova |
| collection | DOAJ |
| description | The time dynamics of nonequilibrium charge carrier relaxation processes in SI GaAs:EL2 (semi-insulating gallium arsenide compensated with EL2 centers) and HR GaAs:Cr (high-resistive gallium arsenide compensated with chromium) were studied by the optical pump–terahertz probe technique. Charge carrier lifetimes and contributions from various recombination mechanisms were determined at different injection levels using the model, which takes into account the influence of surface and volume Shockley–Read–Hall (SRH) recombination, interband radiative transitions and interband and trap-assisted Auger recombination. It was found that, in most cases for HR GaAs:Cr and SI GaAs:EL2, Auger recombination mechanisms make the largest contribution to the recombination rate of nonequilibrium charge carriers at injection levels above ~(0.5–3)·10<sup>18</sup> cm<sup>−3</sup>, typical of pump–probe experiments. At a lower photogenerated charge carrier concentration, the SRH recombination prevails. The derived charge carrier lifetimes, due to the SRH recombination, are approximately 1.5 and 25 ns in HR GaAs:Cr and SI GaAs:EL2, respectively. These values are closer to but still lower than the values determined by photoluminescence decay or charge collection efficiency measurements at low injection levels. The obtained results indicate the importance of a proper experimental data analysis when applying terahertz time-resolved spectroscopy to the determination of charge carrier lifetimes in semiconductor crystals intended for the fabrication of devices working at lower injection levels than those at measurements by the optical pump–terahertz probe technique. It was found that the charge carrier lifetime in HR GaAs:Cr is lower than that in SI GaAs:EL2 at injection levels > 10<sup>16</sup> cm<sup>−3</sup>. |
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| issn | 2304-6732 |
| language | English |
| last_indexed | 2024-03-10T03:18:08Z |
| publishDate | 2021-12-01 |
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| spelling | doaj.art-1e014f4febe9469e84e877308ff167fc2023-11-23T10:09:04ZengMDPI AGPhotonics2304-67322021-12-0181257510.3390/photonics8120575Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier LifetimesIrina A. Kolesnikova0Daniil A. Kobtsev1Ruslan A. Redkin2Vladimir I. Voevodin3Anton V. Tyazhev4Oleg P. Tolbanov5Yury S. Sarkisov6Sergey Yu. Sarkisov7Victor V. Atuchin8Laboratory of Ionizing Radiation Detectors, R&D Center “Advanced Electronic Technologies”, Tomsk State University, 634050 Tomsk, RussiaLaboratory of Optical Structures and Applied Photonics, R&D Center “Advanced Electronic Technologies”, Tomsk State University, 634050 Tomsk, RussiaLaboratory of Optical Structures and Applied Photonics, R&D Center “Advanced Electronic Technologies”, Tomsk State University, 634050 Tomsk, RussiaLaboratory for Terahertz Research, Tomsk State University, 634050 Tomsk, RussiaLaboratory of Ionizing Radiation Detectors, R&D Center “Advanced Electronic Technologies”, Tomsk State University, 634050 Tomsk, RussiaLaboratory of Ionizing Radiation Detectors, R&D Center “Advanced Electronic Technologies”, Tomsk State University, 634050 Tomsk, RussiaDepartment of Physics, Chemistry and Theoretical Mechanics, Tomsk State University of Architecture and Building, 634003 Tomsk, RussiaLaboratory for Terahertz Research, Tomsk State University, 634050 Tomsk, RussiaLaboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, 630090 Novosibirsk, RussiaThe time dynamics of nonequilibrium charge carrier relaxation processes in SI GaAs:EL2 (semi-insulating gallium arsenide compensated with EL2 centers) and HR GaAs:Cr (high-resistive gallium arsenide compensated with chromium) were studied by the optical pump–terahertz probe technique. Charge carrier lifetimes and contributions from various recombination mechanisms were determined at different injection levels using the model, which takes into account the influence of surface and volume Shockley–Read–Hall (SRH) recombination, interband radiative transitions and interband and trap-assisted Auger recombination. It was found that, in most cases for HR GaAs:Cr and SI GaAs:EL2, Auger recombination mechanisms make the largest contribution to the recombination rate of nonequilibrium charge carriers at injection levels above ~(0.5–3)·10<sup>18</sup> cm<sup>−3</sup>, typical of pump–probe experiments. At a lower photogenerated charge carrier concentration, the SRH recombination prevails. The derived charge carrier lifetimes, due to the SRH recombination, are approximately 1.5 and 25 ns in HR GaAs:Cr and SI GaAs:EL2, respectively. These values are closer to but still lower than the values determined by photoluminescence decay or charge collection efficiency measurements at low injection levels. The obtained results indicate the importance of a proper experimental data analysis when applying terahertz time-resolved spectroscopy to the determination of charge carrier lifetimes in semiconductor crystals intended for the fabrication of devices working at lower injection levels than those at measurements by the optical pump–terahertz probe technique. It was found that the charge carrier lifetime in HR GaAs:Cr is lower than that in SI GaAs:EL2 at injection levels > 10<sup>16</sup> cm<sup>−3</sup>.https://www.mdpi.com/2304-6732/8/12/575SI GaAs:CrHR GaAs:Croptical pump–terahertz probecharge carrier lifetimeShockley–Read–Hall recombinationAuger recombination |
| spellingShingle | Irina A. Kolesnikova Daniil A. Kobtsev Ruslan A. Redkin Vladimir I. Voevodin Anton V. Tyazhev Oleg P. Tolbanov Yury S. Sarkisov Sergey Yu. Sarkisov Victor V. Atuchin Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes Photonics SI GaAs:Cr HR GaAs:Cr optical pump–terahertz probe charge carrier lifetime Shockley–Read–Hall recombination Auger recombination |
| title | Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes |
| title_full | Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes |
| title_fullStr | Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes |
| title_full_unstemmed | Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes |
| title_short | Optical Pump–Terahertz Probe Study of HR GaAs:Cr and SI GaAs:EL2 Structures with Long Charge Carrier Lifetimes |
| title_sort | optical pump terahertz probe study of hr gaas cr and si gaas el2 structures with long charge carrier lifetimes |
| topic | SI GaAs:Cr HR GaAs:Cr optical pump–terahertz probe charge carrier lifetime Shockley–Read–Hall recombination Auger recombination |
| url | https://www.mdpi.com/2304-6732/8/12/575 |
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