Figure 3: High-resolution aberration-corrected STEM analysis of ZnSe shell
(a) STEM image of a CdS/CdSe/ZnSe DHNR. Scale bar, 1 nm. (b) Z-contrast intensity of representative individual cation–anion column pairs—labelled b1 (CdSe-rich center of the tip) and b2 (mixed CdSe and ZnSe outer region of the tip) in (a). (c) Z-contrast intensity analysis of cation and anion column pairs along the perpendicular direction to the rod axis. Filled circles correspond to the average of all line scans of cation/anion pair columns along the direction of the arrow inside dotted rectangle labeled c1 in the STEM image of (a). Open squares correspond to the direction indicated for dotted rectangle labeled c2 in the STEM image of (a). Z-contrast is defined as (Ianion−Ication)/Ication, where Ij is the count of scattered electrons for ion column j.
