TY  - JOUR
AU  - Borghardt, Sven
AU  - Winkler, Florian
AU  - Zanolli, Z.
AU  - Verstraete, M. J.
AU  - Barthel, Juri
AU  - Tavabi, A. H.
AU  - Dunin-Borkowski, Rafal
AU  - Kardynal, Beata
TI  - Quantitative agreement between electron-optical phase images of WSe2 and simulations based on electrostatic potentials that include bonding effects
JO  - Physical review letters
VL  - 118
IS  - 8
SN  - 1079-7114
CY  - College Park, Md.
PB  - APS
M1  - FZJ-2017-01504
SP  - 086101
PY  - 2017
AB  - The quantitative analysis of electron-optical phase images recorded using off-axis electron holography often relies on the use of computer simulations of electron propagation through a sample. However, simulations that make use of the independent atom approximation are known to overestimate experimental phase shifts by approximately 10%, as they neglect bonding effects. Here, we compare experimental and simulated phase images for few-layer WSe2. We show that a combination of pseudopotentials and all-electron density functional theory calculations can be used to obtain accurate mean electron phases, as well as improved atomic-resolution spatial distribution of the electron phase. The comparison demonstrates a perfect contrast match between experimental and simulated atomic-resolution phase images for a sample of precisely known thickness. The low computational cost of this approach makes it suitable for the analysis of large electronic systems, including defects, substitutional atoms, and material interfaces.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000394667600004
C6  - pmid:28282203
DO  - DOI:10.1103/PhysRevLett.118.086101
UR  - https://juser.fz-juelich.de/record/827368
ER  -