Regensburg 2016 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 26: Poster session II
MM 26.19: Poster
Dienstag, 8. März 2016, 18:30–20:30, Poster B3
Probing the dynamics of piezoelectric field in GaN nanorods by in-situ bending in transmission electron microscope with differential phase contrast and electron diffraction mapping — •Mingjian Wu1, Florian Niekiel1, Christel Dieker1, Silke Christiansen2, and Erdmann Spiecker1 — 1WW9 & CENEM, Department Werkstoffwissenschaften, FAU Erlangen-Nürnberg, Cauerstr. 6, 91058 Erlangen, Germany — 2MPI for the Science of Light, Günther-Scharowski-Str. 1, 91058 Erlangen, Germany
Probing the electric properties of functional semiconductors in nano-scale resolution is of great interest, because it allows direct visualization of the relation to the local structure and especially defects. Inversion domain boundary (IDB) is one of the common defects found in wurtzite GaN, a polar crystal with piezoelectricity. As is known, piezoelectricity couples to the polarity of crystal and the sign of applied stresses. For wurtzite GaN nanorods with IDB upon mechanical bending, the piezoelectric field and charge distribution would be expected to be greatly different to normal GaN nanorods. Experimentally, electric fields can be visualized down to atomic scale, in principle, by the deflection of electron probe (i.e., differential phase contrast (DPC)). In this work, we perform in-situ mechnical bending of GaN nanorods with side-to-side IDB in the TEM, and acquire DPC micrographs and convergent beam electron diffraction pattern arrays to infer the dynamics of piezoelectric field in the GaN nanorods. Interesting findings and comprehensive data evaluation and interpretation will be presented.