Controlling crystalline structure of ZnS nanocrystals only by tuning sulfur precursor addition rate.

Unlike previous studies that emphasize the important role of thermodynamics or surface energy on the structure stabilization of ZnS nanocrystals, we successfully controlled the crystalline structure of ZnS nanocrystals simply by tuning sulfur precursor addition rate under exactly the same other conditions. We observed the structure of as prepared ZnS nanocrystals was evolved from wurtzite into zinc blende with increasing the addition rate of sulfur precursor. The method may extend to engineer other nanomaterials with desired physicochemical properties by controlling crystalline structure. On the other hand, it also makes a new approach to understand the crucial factors that determine the growth mechanism and the crystal structure of nanomaterials in theory.