Insertion/Ejection of Dopant Ions in Composition Tunable Semiconductor Nanocrystals

A new doping strategy to incorporate transition metal dopant ions in semiconductor hosts has been reported here where dopant ions are incorporated in the host lattice following a feasible cation exchange process. Composition variable CdxZn1-xSe alloy nanocrystals have been chosen as an appropriate host which is formed by the cation exchange reaction of Cd with Zn ions in ZnSe nanocrystals. Concomitant insertion and ejection of dopant Cu ions are studied. It has been observed that the composition of Zn and Cd in the nanocrystals decides how much dopant Cu ions will be retained in the host lattice. The entire doping process with evolution, wide range tuning, and quenching of dopant emission as a consequence of inclusion/exclusion of dopant ions is in situ measured during the alloying process. From the retained and expelled dopant amounts, their compatibility in the host lattice is correlated.