In situ XAFS studies on the growth of ZnSe quantum dots

The growth mechanism of glutathione (GSH) capped ZnSe quantum dots (QDs) obtained from the aqueous synthesis method is studied by in situ X-ray absorption fine structure (XAFS) utilizing a flow reactor and synchrotron radiation. Detailed analysis of the Se K-edge EXAFS data reveals that the growth of ZnSe QDs from aqueous synthesis undergoes a fast nucleation process and then a slow growth stage, which follows the two-stage growth mechanism. The ZnSe QDs are strained to minimize the total free energy, and the contraction of Se–Zn bond relaxes with time. This shows the promising capability of in situ XAFS to investigate the growth process of nano-materials synthesized by chemical solution method.