TY - JOUR
T1 - Quantitative chemical mapping of InGaN quantum wells from calibrated high-angle annular dark field micrographs
AU - Carvalho, Daniel
AU - Morales, Francisco M.
AU - Ben, Teresa
AU - García, Rafael
AU - Redondo-Cubero, Andrés
AU - Alves, Eduardo
AU - Lorenz, Katharina
AU - Edwards, Paul R.
AU - O'Donnell, Kevin P.
AU - Wetzel, Christian
PY - 2015/8
Y1 - 2015/8
N2 - We present a simple and robust method to acquire quantitative maps of compositional fluctuations in nanostructures from low magnification high-angle annular dark field (HAADF) micrographs calibrated by energy-dispersive X-ray (EDX) spectroscopy in scanning transmission electron microscopy (STEM) mode. We show that a nonuniform background in HAADF-STEM micrographs can be eliminated, to a first approximation, by use of a suitable analytic function. The uncertainty in probe position when collecting an EDX spectrum renders the calibration of HAADF-STEM micrographs indirect, and a statistical approach has been developed to determine the position with confidence. Our analysis procedure, presented in a flowchart to facilitate the successful implementation of the method by users, was applied to discontinuous InGaN/GaN quantum wells in order to obtain quantitative determinations of compositional fluctuations on the nanoscale.
AB - We present a simple and robust method to acquire quantitative maps of compositional fluctuations in nanostructures from low magnification high-angle annular dark field (HAADF) micrographs calibrated by energy-dispersive X-ray (EDX) spectroscopy in scanning transmission electron microscopy (STEM) mode. We show that a nonuniform background in HAADF-STEM micrographs can be eliminated, to a first approximation, by use of a suitable analytic function. The uncertainty in probe position when collecting an EDX spectrum renders the calibration of HAADF-STEM micrographs indirect, and a statistical approach has been developed to determine the position with confidence. Our analysis procedure, presented in a flowchart to facilitate the successful implementation of the method by users, was applied to discontinuous InGaN/GaN quantum wells in order to obtain quantitative determinations of compositional fluctuations on the nanoscale.
KW - chemical mapping
KW - energy dispersive X-ray spectroscopy
KW - InGaN/GaN quantum well
KW - HAADF-STEM
KW - RBS
KW - EDX
UR - http://journals.cambridge.org/action/displayBackIssues?jid=MAM
U2 - 10.1017/S143192761501301X
DO - 10.1017/S143192761501301X
M3 - Article
SN - 1431-9276
VL - 21
SP - 994
EP - 1005
JO - Microscopy and Microanalysis
JF - Microscopy and Microanalysis
IS - 4
ER -