Composition determination of semiconductor alloys towards atomic accuracy by HAADF-STEM

L Duschek, P Kükelhan, A Beyer, S Firoozabadi… - Ultramicroscopy, 2019 - Elsevier
This paper presents a comprehensive investigation of an extended method to determine
composition of materials by scanning transmission electron microscopy (STEM) high angle …

Controlled formation of stacked si quantum dots in vertical SiGe nanowires

EM Turner, Q Campbell, J Pizarro, H Yang… - Nano Letters, 2021 - ACS Publications
We demonstrate the ability to fabricate vertically stacked Si quantum dots (QDs) within SiGe
nanowires with QD diameters down to 2 nm. These QDs are formed during high-temperature …

Sampling optimization of Moiré geometrical phase analysis for strain characterization in scanning transmission electron microscopy

A Pofelski, S Ghanad-Tavakoli, DA Thompson… - Ultramicroscopy, 2020 - Elsevier
A strain characterization technique in a Scanning Transmission Electron Microscope (STEM)
called “STEM Moiré GPA”(SMG) emerged recently as an efficient method to map the …

Segregation at interfaces in (GaIn) As/Ga (AsSb)/(GaIn) As-quantum well heterostructures explored by atomic resolution STEM

P Kükelhan, S Firoozabadi, A Beyer, L Duschek… - Journal of Crystal …, 2019 - Elsevier
Surface segregation and interaction effects of In and Sb in (GaIn) As/Ga (AsSb)/(GaIn) As-
“W”-type quantum well heterostructures (“W”-QWHs) are investigated by high angle annular …

Angle-dependence of ADF-STEM intensities for chemical analysis of InGaN/GaN

T Grieb, FF Krause, K Müller-Caspary, JP Ahl… - Ultramicroscopy, 2022 - Elsevier
In this paper we perform angular resolved annular-dark field (ADF) scanning-transmission
electron microscopy (STEM) to study the scattered intensity in an InGaN layer buried in GaN …

Quantitative composition determination by ADF-STEM at a low-angular regime: A combination of EFSTEM and 4DSTEM

S Firoozabadi, P Kükelhan, A Beyer, J Lehr, D Heimes… - Ultramicroscopy, 2022 - Elsevier
High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) is
a valuable method for composition determination of nanomaterials. However, light elements …

Surface relaxation of strained Ga (P, As)/GaP heterostructures investigated by HAADF STEM

A Beyer, L Duschek, J Belz, JO Oelerich… - Journal of …, 2017 - Wiley Online Library
The surfaces of thin transmission electron microscopy (TEM) specimens of strained
heterostructures can relax. The resulting bending of the lattice planes significantly influences …

Atomic structure of 'W'‐type quantum well heterostructures investigated by aberration‐corrected STEM

P Kükelhan, A Beyer, C Fuchs, MJ Weseloh… - Journal of …, 2017 - Wiley Online Library
The atomic structure of (GaIn) As/Ga (AsSb)/(GaIn) As‐'W'‐type quantum well
heterostructures ('W'‐QWHs) is investigated by scanning transmission electron microscopy …

Assessment of the strain depth sensitivity of moire sampling scanning transmission electron microscopy geometrical phase analysis through a comparison with dark …

A Pofelski, V Whabi, S Ghanad-Tavakoli, G Botton - Ultramicroscopy, 2021 - Elsevier
In this study, the Moiré sampling Scanning Transmission Electron Microscopy Geometrical
Phase Analysis (or STEM Moiré GPA) strain characterization method is compared to the well …

Simultaneous determination of local thickness and composition for ternary III-V semiconductors by aberration-corrected STEM

P Kükelhan, A Beyer, S Firoozabadi, T Hepp, K Volz - Ultramicroscopy, 2019 - Elsevier
Scanning transmission electron microscopy (STEM) is a suitable method for the quantitative
characterization of nanomaterials. For an absolute composition determination on an atomic …