Organometallic methods (also known

Organometallic methods (also known as the hot injection methods) use organometallic precursors possessing a fixed stoichiometric ratio of the metal cations dissolved in some organic solvent. It provides an ideal environment for controlling NCs growth because the nucleation process and the subsequent growth processes are separated. In a typical organometallic process, as depicted in Fig. 4, the organometallic precursors are quickly injected into the reaction system at a high temperature, leading to rapid nucleation. The temperature drops after injection of precursors and the growth process starts to occur. Surfactants or stabilizing agents are usually present in this crystal growth process for controlling the morphology of the resulting NCs.38 So far, this method has achieved great success in synthesizing a rich variety of NCs, including semiconductor37–39 and metal oxide125–127 types, and is widely regarded as the best approach for controlling both the size and morphology of the resulting NCs.128