Semiconductor Nanocrystal Engineering by Applying Thiol‐ and Solvent‐Coordinated Cation Exchange Kinetics.

Thiol‐ and solvent‐coordinated cation exchange kinetics have been applied to engineer the composition and crystallinity of novel nanocrystals. The detailed thermodynamics and kinetics of the reactions were explored by NMR spectroscopy, time‐dependent photoluminescence (PL) characterizations and theoretical simulations. The fine structure of the colloidal semiconductor nanocrystals (CSNCs) was investigated by X‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS). In this way, high‐quality p‐type Ag‐doped ZnS quantum dots (QDs) and Au@ZnS hetero‐nanocrystals with a cubic phase ZnS shell were synthesized successfully.The unprecedented dominant Ag+‐dopant‐induced fluorescence and p‐type conductivity in the zinc‐blende ZnS are reported. The right combination of thiol and solvent allows the resulting nanocrystal to be engineered by modulating the cation exchange kinetics. By applying this method, high‐quality p‐type Ag‐doped ZnS quantum dots (QDs) and Au@ZnS hetero‐nanocrystals with a cubic phase ZnS shell were synthesized successfully. [ABSTRACT FROM AUTHOR]