Modulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobility
Reliable doping is required to realize many devices based on semiconductor nanowires. Group III-V nanowires show great promise as elements of high-speed optoelectronic devices, but for such applications it is important that the electron mobility is not compromised by the inclusion of dopants. Here w...
| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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American Chemical Society
2015
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| _version_ | 1826262555559985152 |
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| author | Boland, J Conesa-Boj, S Parkinson, P Tütüncüoglu, G Matteini, F Rüffer, D Casadei, A Amaduzzi, F Jabeen, F Davies, C Joyce, H Herz, L Fontcuberta i Morral, A Johnston, M |
| author_facet | Boland, J Conesa-Boj, S Parkinson, P Tütüncüoglu, G Matteini, F Rüffer, D Casadei, A Amaduzzi, F Jabeen, F Davies, C Joyce, H Herz, L Fontcuberta i Morral, A Johnston, M |
| author_sort | Boland, J |
| collection | OXFORD |
| description | Reliable doping is required to realize many devices based on semiconductor nanowires. Group III-V nanowires show great promise as elements of high-speed optoelectronic devices, but for such applications it is important that the electron mobility is not compromised by the inclusion of dopants. Here we show that GaAs nanowires can be n-type doped with negligible loss of electron mobility. Molecular beam epitaxy was used to fabricate modulation-doped GaAs nanowires with Al0.33Ga0.67As shells that contained a layer of Si dopants. We identify the presence of the doped layer from a high-angle annular dark field scanning electron microscopy cross-section image. The doping density, carrier mobility, and charge carrier lifetimes of these n-type nanowires and nominally undoped reference samples were determined using the noncontact method of optical pump terahertz probe spectroscopy. An n-type extrinsic carrier concentration of 1.10 ± 0.06 × 10(16) cm(-3) was extracted, demonstrating the effectiveness of modulation doping in GaAs nanowires. The room-temperature electron mobility was also found to be high at 2200 ± 300 cm(2) V(-1) s(-1) and importantly minimal degradation was observed compared with undoped reference nanowires at similar electron densities. In addition, modulation doping significantly enhanced the room-temperature photoconductivity and photoluminescence lifetimes to 3.9 ± 0.3 and 2.4 ± 0.1 ns respectively, revealing that modulation doping can passivate interfacial trap states. |
| first_indexed | 2024-03-06T19:38:04Z |
| format | Journal article |
| id | oxford-uuid:1fb48876-e8f6-4b1f-ba48-4f256fab0538 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:38:04Z |
| publishDate | 2015 |
| publisher | American Chemical Society |
| record_format | dspace |
| spelling | oxford-uuid:1fb48876-e8f6-4b1f-ba48-4f256fab05382022-03-26T11:23:28ZModulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobilityJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1fb48876-e8f6-4b1f-ba48-4f256fab0538EnglishSymplectic Elements at OxfordAmerican Chemical Society2015Boland, JConesa-Boj, SParkinson, PTütüncüoglu, GMatteini, FRüffer, DCasadei, AAmaduzzi, FJabeen, FDavies, CJoyce, HHerz, LFontcuberta i Morral, AJohnston, MReliable doping is required to realize many devices based on semiconductor nanowires. Group III-V nanowires show great promise as elements of high-speed optoelectronic devices, but for such applications it is important that the electron mobility is not compromised by the inclusion of dopants. Here we show that GaAs nanowires can be n-type doped with negligible loss of electron mobility. Molecular beam epitaxy was used to fabricate modulation-doped GaAs nanowires with Al0.33Ga0.67As shells that contained a layer of Si dopants. We identify the presence of the doped layer from a high-angle annular dark field scanning electron microscopy cross-section image. The doping density, carrier mobility, and charge carrier lifetimes of these n-type nanowires and nominally undoped reference samples were determined using the noncontact method of optical pump terahertz probe spectroscopy. An n-type extrinsic carrier concentration of 1.10 ± 0.06 × 10(16) cm(-3) was extracted, demonstrating the effectiveness of modulation doping in GaAs nanowires. The room-temperature electron mobility was also found to be high at 2200 ± 300 cm(2) V(-1) s(-1) and importantly minimal degradation was observed compared with undoped reference nanowires at similar electron densities. In addition, modulation doping significantly enhanced the room-temperature photoconductivity and photoluminescence lifetimes to 3.9 ± 0.3 and 2.4 ± 0.1 ns respectively, revealing that modulation doping can passivate interfacial trap states. |
| spellingShingle | Boland, J Conesa-Boj, S Parkinson, P Tütüncüoglu, G Matteini, F Rüffer, D Casadei, A Amaduzzi, F Jabeen, F Davies, C Joyce, H Herz, L Fontcuberta i Morral, A Johnston, M Modulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobility |
| title | Modulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobility |
| title_full | Modulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobility |
| title_fullStr | Modulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobility |
| title_full_unstemmed | Modulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobility |
| title_short | Modulation doping of GaAs/AlGaAs core-shell nanowires with effective defect passivation and high electron mobility |
| title_sort | modulation doping of gaas algaas core shell nanowires with effective defect passivation and high electron mobility |
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