Regensburg 2022 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 22: Heterostructures, Interfaces and Surfaces
HL 22.5: Talk
Wednesday, September 7, 2022, 16:00–16:15, H33
Interplay of anomalous strain relaxation and minimization of polarization changes at nitride semiconductor heterointerfaces — Yuhan Wang1,2, •Michael Schnedler1,2, Qianqian Lan1,2, Fengshan Zheng1,2, Lars Freter1,2, Yan Lu1,2, Uwe Breuer3, Holger Eisele4, Jean-François Carlin5, Raphaël Butté5, Nicolas Grandjean5, Rafal E. Dunin-Borkowski1,2, and Philipp Ebert1,2 — 1Peter Grünberg Institut, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — 2Ernst Ruska Centrum, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — 3Zentralinstitut für Engineering, Elektronik und Analytik (ZEA-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany — 4Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany — 5Institute of Physics, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
Polarization and electron affinity changes at Al0.06Ga0.94N/GaN and In0.05Ga0.95N/Al0.06Ga0.94N interfaces are quantified by combining off-axis electron holography in transmission electron microscopy, scanning tunneling microscopy, and simulations of the electrostatic potential and electron phase maps. The In0.05Ga0.95N/Al0.06Ga0.94N interface reveals, as expected, biaxial relaxation as well as polarization and electron affinity changes. However, at the Al0.06Ga0.94N/GaN interface anomalous lattice relaxations and vanishing polarization and electron affinity changes occur, whose underlying physical origin is anticipated to be total energy minimization by the minimization of Coulomb interactions between the polarization-induced interface charges.