Structural basis for near unity quantum yield core/shell nanostructures.
Aberration-corrected Z-contrast scanning transmission electron microscopy of core/shell nanocrystals shows clear correlations between structure and quantum efficiency. Uniform shell coverage is obtained only for a graded CdS/ZnS shell material and is found to be critical to achieving near 100% quantum yield. The sublattice sensitivity of the images confirms that preferential growth takes place on the anion-terminated surfaces. This explains the three-dimensional "nanobullet" shape observed in the case of core/shell nanorods.
McBride
James
J
Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA.
Treadway
Joe
J
Feldman
L C
LC
Pennycook
Stephen J
SJ
Rosenthal
Sandra J
SJ
D019187:Cadmium Compounds / Q000737:chemistry*; D017348:Microscopy, Electron, Scanning Transmission; D049329:Nanostructures / Q000737:chemistry*; D045663:Quantum Dots; D013440:Sulfides / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
D019187:Cadmium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C034939:cadmium sulfide; C031238:zinc sulfide