Synthesis of Doped ZnS Nanoclusters within Block Copolymer Nanoreactors

Abstract

We have synthesized Mn-doped and Tb-doped ZnS nanoclusters within the microphase-separated films of diblock copolymers containing carboxylic acid units on one of the blocks. The loading of metal ions can be monitored using inductively coupled plasma atomic emission spectroscopy. The impurity ion content of the acid-containing microdomains can be controlled by varying the concentration of the aqueous metal salt solutions or the time of exposure of the films to the aqueous salt solution. The doped ZnS nanoclusters are formed by subsequently treating the ion-loaded films with H 2 S. The doped nanoclusters are optically active and show emission characteristic of the impurity ions (manganese or terbium). The universal nanocluster synthesis scheme could in principle be used with various combinations of metal salts to yield many different doped semiconductor nanocluster species.