TY  - JOUR
AU  - Müller-Caspary, Knut
AU  - Grieb, Tim
AU  - Müßener, Jan
AU  - Gauquelin, Nicolas
AU  - Hille, Pascal
AU  - Schörmann, Jörg
AU  - Verbeeck, Johan
AU  - Van Aert, Sandra
AU  - Eickhoff, Martin
AU  - Rosenauer, Andreas
TI  - Electrical Polarization in AlN/GaN Nanodisks Measured by Momentum-Resolved 4D Scanning Transmission Electron Microscopy
JO  - Physical review letters
VL  - 122
IS  - 10
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2019-01297
SP  - 106102
PY  - 2019
AB  - We report the mapping of polarization-induced internal electric fields in AlN/GaN nanowire heterostructures at unit cell resolution as a key for the correlation of optical and structural phenomena in semiconductor optoelectronics. Momentum-resolved aberration-corrected scanning transmission electron microscopy is employed as a new imaging mode that simultaneously provides four-dimensional data in real and reciprocal space. We demonstrate how internal mesoscale and atomic electric fields can be separated in an experiment, which is verified by comprehensive dynamical simulations of multiple electron scattering. A mean difference of 5.3±1.5  MV/cm is found for the polarization-induced electric fields in AlN and GaN, being in accordance with dedicated simulations and photoluminescence measurements in previous publications.
LB  - PUB:(DE-HGF)16
C6  - pmid:30932647
UR  - <Go to ISI:>//WOS:000461067700007
DO  - DOI:10.1103/PhysRevLett.122.106102
UR  - https://juser.fz-juelich.de/record/860624
ER  -