Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 4: GaN: Bauelemente
HL 4.7: Vortrag
Montag, 24. März 2003, 12:00–12:15, BEY/154
Simulation of polarization effects in AlN/GaN-based RTDs — •K. M. Indlekofer1, E. Donà1, M. Kočan1, J. Malindretos2, M. Bertelli1, A. Rizzi3 und H. Lüth1 — 1ISG1, Forschungszentrum Jülich GmbH, D-52078 Jülich, Germany — 2Dept. of Electr. Eng., Arizona State University, AZ 85287, USA — 3IV. Physikalisches Inst., Georg-August-Universität Göttingen, D-37073 Göttingen, Germany
Polarization charges at hetero-interfaces in epitaxially grown wurtzite-AlN/GaN device structures lead to a significant modification of the self-consistent potential profile and, hence, influence its transport properties. This is especially important when dealing with nanometer-scale device concepts, which are based on quantum mechanical effects. In this contribution, we present numerical simulations for electronic transport through an AlN/GaN-based resonant tunneling diode (RTD) structure. The employed transport model [1] is based on a non-equilibrium tight-binding Green’s function formulation, considering self-consistent Hartree-potentials including polarization charges.
The simulated current-voltage characteristics for a realistic RTD structure reveal strong asymmetry effects, which can clearly be attributed to polarization charges at the hetero-interfaces in the double-barrier region of the RTD. In order to interpret the influence of these polarization layers, we discuss the self-consistent single-particle potential profile and the local electron-charge density as a function of the applied bias voltage and its polarity [2].
[1] Download: http://www.fz-juelich.de/isg/mbe/wingreen.html
[2] K. M. Indlekofer et al., phys. stat. sol (b) 234, 769 (2002)