%0 Journal Article
%A Borghardt, Sven
%A Winkler, Florian
%A Zanolli, Z.
%A Verstraete, M. J.
%A Barthel, Juri
%A Tavabi, A. H.
%A Dunin-Borkowski, Rafal
%A Kardynal, Beata
%T Quantitative agreement between electron-optical phase images of WSe2 and simulations based on electrostatic potentials that include bonding effects
%J Physical review letters
%V 118
%N 8
%@ 1079-7114
%C College Park, Md.
%I APS
%M FZJ-2017-01504
%P 086101
%D 2017
%X 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.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000394667600004
%$ pmid:28282203
%R 10.1103/PhysRevLett.118.086101
%U https://juser.fz-juelich.de/record/827368