SKM 2021 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 20: Quantum Dots and Wires (joint session HL/TT)

TT 20.9: Talk

Thursday, September 30, 2021, 16:00–16:15, H4

Electrical Characterisation of Te-doped InAs Nanowires grown by VS Molecular Beam Epitaxy — •Anton Faustmann, Pujitha Perla, Detlev Grützmacher, Mihail Lepsa und Thomas Schäpers — Peter-Grünberg-Institut PGI-9, FZ-Jülich, Jülich, Deutschland

InAs features high electron mobility and absence of a Schottky barrier at metal interfaces enabling ohmic contacts. In combination with large g-factor and high Rashba spin-orbit coupling this makes InAs nanowires a promising candidate for research of quantum effects. InAs nanowires with Te doping grown by molecular beam epitaxy were investigated in terms of their electrical transport properties at both room and cryogenic temperatures. The nanowires were grown in a catalyst-free vapour-solid process without using Au droplets. In contrast to Si, which shows amphoteric behaviour, Te acts as n-type dopant. It furthermore offers the possibility of an increased overall doping level. The Te doping concentration was found to affect both the morphology of the nanowires as well as electrical properties. The shape of the nanowires depends on Te uptake. Their intrinsic as well as contact resistances decrease considerably at increased doping level. Field-effect measurements using a global back gate show effect on the conductance, depending on the doping concentration. For higher doping no complete pinch-off was observable with conductance saturating at high negative gate voltages. Resistances were found to be only slightly increased at cryogenic temperatures.