Berlin 2018 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 27: Nitrides: Preparation and characterization II
HL 27.4: Vortrag
Mittwoch, 14. März 2018, 10:15–10:30, EW 203
Charging of self-assembled GaN quantum dot ensembles by Capacitance-Voltage spectroscopy at room temperature — •Carlo A. Sgroi1, Julien Brault2, Jean Y. Duboz2, Arne Ludwig1, and Andreas D. Wieck1 — 1Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany — 2CNRS * CRHEA, Rue Bernard Grégory, 06560 Valbonne, France
We present a capacitance voltage (CV) measurement of charge-tunable self-assembled wurtzite GaN quantum dots (QDs) in an AlxGa1−xN matrix at room temperature grown by MBE.
GaN and its alloys have excellent properties which makes them an ideal candidate for high power and high temperature microelectronic and QD storage devices, such as their thermal stability, high thermal conductivity and wide bandgap energies.
Due to polarization effects in wurtzite GaN/AlxGa1−xN heterostructure layers the band structure is deformed. Band structure simulations were run to calculate a proper tunneling barrier and to estimate the quantum dot minimum to be close to the Fermi energy level with a sufficient lever arm to bring the QD energy levels in resonance with the Fermi energy.
Performing CV spectroscopy at room temperature we were able to evaluate a Coulomb blockade energy for electrons in the ground state of approximately 63 meV.