CUED Publications database

Terahertz spectroscopy of modulation doped core-shell GaAs/AlGaAs nanowires

Boland, JL and Conesa-Boj, S and Tütüncouglu, G and Matteini, F and Rüffer, D and Casadei, A and Gaveen, F and Amaduzzi, F and Parkinson, P and Davies, C and Joyce, HJ and Herz, LM and Morral, AFI and Johnston, MB (2015) Terahertz spectroscopy of modulation doped core-shell GaAs/AlGaAs nanowires. In: UNSPECIFIED.

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© 2015 IEEE. In order to realize many devices based on semiconductor nanowires, reliable doping is essential. For such devices, it is important that the electron mobility is not compromised by doping incorporation. Here, we show that core-shell GaAs/AlGaAs nanowires can be modulation n-type doped with negligible loss of electron mobility. Optical pump terahertz probe spectroscopy is used as a novel, reliable, noncontact method of determining the doping density, carrier mobility and charge carrier lifetimes for these n-type nanowires and an undoped reference. A carrier concentration of 1.10 ± 0.06 × 10 16 cm -3 was extracted proving the effectiveness of modulation doping in GaAs nanowires. The room-temperature electron mobility was found to be high at 2200 ± 300 cm 2 V -1 s -1 with no degradation in comparison to undoped reference nanowires. In addition, modulation doping was found to enhance both the photoconductivity and photoluminescence lifetimes to 3.9 ± 0.3ns and 2.4 ± 0.1ns respectively, revealing that modulation doping can passivate interfacial trap states. 1

Item Type: Conference or Workshop Item (UNSPECIFIED)
Divisions: Div B > Solid State Electronics and Nanoscale Science
Depositing User: Cron Job
Date Deposited: 17 Jul 2017 19:33
Last Modified: 22 May 2018 07:35