Chelation of Zn Cations as a Method for Their Replacement by Mn, Fe, Co in ZnSe Nanocrystals.

This article describes a new technique for postsynthetic doping/alloying of Mn into ZnSe nanocrystals. The key feature is that it employs diethyldithiocarbamate anion to selectively bind the host cations and promote ion exchange. The presence of Mn in the product is confirmed with photoluminescence (PL) and total reflection X‐ray fluorescence spectroscopy. The cation exchange reaction takes place at temperatures as low as 100 °C. Higher temperatures allow to incorporate the impurity in greater quantities; however, after a crossover temperature of ≈200 °C, the process gets convoluted with Ostwald ripening and sulfide deposition, as evident from electron diffraction data, high‐resolution transmission electron microscopy (HR‐TEM), and elemental analysis of the samples. Studies of PL lifetime and quantum yield confirm these findings. Preliminary success is also shown for other impurities: Fe and Co are present in the respective samples in ≈17 at% of total metal content. [ABSTRACT FROM AUTHOR]