Graded synthetic approach for the fabrication of nanocrystal quantum dots for enhanced carrier injection in light-emitting diodes

A synthetic approach for fabricating compositionally graded multishell nanocrystal quantum dots (NQDs) from cubic CdSe is presented. The structural shapes with each shell formation were examined using scanning transmission electron microscopy (STEM) coupled with energy dispersive x-ray spectroscopy and electron energy loss spectroscopy (EELS). The optical properties probed via time-resolved spectroscopy further revealed detailed carrier behavior at the core/graded shell interface. A highly luminescing stable optical device was built using our graded multishell NQDs.