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.