SKM 2023 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 24: Quantum Dots: Transport (joint session HL/TT)
TT 24.3: Vortrag
Dienstag, 28. März 2023, 10:00–10:15, POT 151
Mesoscopic transport properties of individually prepared GaN-nanowire field-effect transistors — •Hannes Hergert1,2, Matthias T. Elm1,2,3, and Peter J. Klar1 — 1Institute of Experimental Physics I, Giessen, Germany — 2Center for Materials Research, Giessen, Germany — 3Institute of Physical Chemistry, Giessen, Germany
In order to keep the optimization of transistors within Moore's law new material systems as well as new transistor concepts such as GaN-nanowire field effect transistors (NW-FET) are needed. In this work we characterize the electrical transport properties of single NW-FET. Furthermore, we are able to obtain a deeper understanding of the mesoscopic transport processes. Unintentionally doped GaN-nanowires were fabricated using molecular-beam-epitaxy and device fabrication was performed by a combination of different lithographic methods and atomic layer deposition. After an annealing process the nanowire's resistance shows an ohmic behaviour. Electrical transport measurements were performed between 2 and 280 K. The investigated NW-FET exhibits a transfer characteristic identical to those of classical field-effect transistors. We show that the electrical transport is dominated by two transport processes: a transport within a metal-like impurity band at low temperatures and a hopping process at higher temperatures. Furthermore we were able to identify universal conductance fluctuations at temperatures below 140 K, which arise from the shift of the Fermi level when applying a topgate voltage.