Charge transport in single-crystalline GaAs nanobars: impact of band bending revealed by terahertz spectroscopy

0552412 - FZÚ 2023 RIV DE eng J - Journal Article
Pushkarev, Vladimir - Němec, Hynek - Paingad, Vaisakh Chelod - Maňák, Jan - Jurka, Vlastimil - Novák, Vít - Ostatnický, T. - Kužel, Petr
Charge transport in single-crystalline GaAs nanobars: impact of band bending revealed by terahertz spectroscopy.
Advanced Functional Materials. Roč. 32, č. 5 (2022), č. článku 2107403. ISSN 1616-301X. E-ISSN 1616-3028
R&D Projects: GA MŠMT(CZ) EF16_019/0000760; GA ČR(CZ) GX19-28375X; GA MŠMT EF16_013/0001405
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760; OP VVV - LNSM(XE) CZ.02.1.01/0.0/0.0/16_013/0001405
Research Infrastructure: CzechNanoLab - 90110
Institutional support: RVO:68378271
Keywords : terahertz spectroscopy * semiconductor nanobars * charge transport
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 19, year: 2022
Method of publishing: Open access with time embargo
https://doi.org/10.1002/adfm.202107403

Arrays of ultimate-quality single-crystalline GaAs nanobars are prepared via electron-beam lithography in a molecular-beam-epitaxy-grown GaAs layer transferred onto an electrically insulating and optically and terahertz transparent sapphire substrate. Measurements of ultrafast terahertz photoconductivity at 300 and 20 K in an array of such aligned nanobars by time-resolved THz and multi-THz spectroscopy and by time-resolved terahertz scanning near-field microscopy allow an in-depth understanding of the nanoscale electron motion inside the nanobars. A detailed analysis is performed in terms of quantum mechanical calculations of the mobility of carriers and in terms of plasmonic resonance controlled by photocarrier density. The investigations reveal a band bending close to the nanobar surfaces and its prominent effects on the picosecond charge carrier dynamics, leading to an enhanced localization of electrons at longer times.
Permanent Link: http://hdl.handle.net/11104/0330417