Open AccessElectron channelling: challenges and opportunities for compositional analysis of nanowires by TEM
Author(s) -
Martin Ek,
Sebastian Lehmann,
Reine Wallenberg
Publication year - 2020
Publication title -
nanotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.926
H-Index - 203
eISSN - 1361-6528
pISSN - 0957-4484
DOI - 10.1088/1361-6528/ab9679
Subject(s) - channelling , nanowire , materials science , transmission electron microscopy , electron , dopant , systematic error , nanotechnology , analytical chemistry (journal) , crystallography , optoelectronics , physics , doping , ion , chemistry , statistics , nuclear physics , mathematics , quantum mechanics , chromatography
Energy dispersive x-ray spectroscopy in a transmission electron microscope is often the first method employed to characterize the composition of nanowires. Ideally, it should be accurate and sensitive down to fractions of an atomic percent, and quantification results are often reported as such. However, one can often get substantial errors in accuracy even though the precision is high: for nanowires it is common for the quantified V/III atomic ratios to differ noticeably from 1. Here we analyse the origin of this systematic error in accuracy for quantification of the composition of III–V nanowires. By varying the electron illumination direction, we find electron channelling to be the primary cause, being responsible for errors in quantified V/III atomic ratio of 50%. Knowing the source of the systematic errors is required for applying appropriate corrections. Lastly, we show how channelling effects can provide information on the crystallographic position of dopants.