Surface Doping for Hindrance of Crystal Growth and Structural Transformation in Semiconductor Nanocrystals

Doping can strongly influence the crystal growth of semiconductor nanocrystals. It can change the surface energy and therefore the growth directions and shape of the host nanocrystals. While doping of transition metal ions in various semiconductor host nanocrystals is widely studied for obtaining new material properties, the effect of doping on crystal growth has been less explored. Herein, we study the change in the crystal growth pattern and growth rate with doping of one of the most common dopants Mn in a ZnSe host. With the help of selective surface binding ligands, hemisphere-shaped zinc blende nanostructures are designed from ZnSe seeds and dopant Mn precursors in different amounts are introduced at different stages of the synthetic process. Monitoring the sequential product and analyzing the surface or internal locations of the dopants, the possibility of shape change has been discussed. Moreover, the mutual effects of crystal growth and doping on one another are also determined considering the progress of the reactions under different conditions. We believe that the results presented here are important for understanding the doping mechanism and its effects during crystal growth in semiconductor nanocrystals, which are not clear to date.