The use of de-aggregating agents in ZnSe mechanochemical synthesis

Conventional mechanochemical synthesis of zinc selenide, ZnSe nanoparticles was performed in a planetary ball mill by high-energy milling of zinc (Zn) and selenium (Se) powders with the de-aggregating agents ZnCl2 and phthalic acid (aromatic dicarboxylic acid, C8H6O4). Physical-chemical and optical properties of the prepared ZnSe nanoparticles were studied and compared. The mechanochemically synthesized products were characterized by X-ray diffraction analysis (XRD) that confirmed the presence of cubic-Stilleite and hexagonal ZnSe phases after 18, 25, 30, 40, 45 and 50 min of milling with various amounts of the added de-aggregating agents. Size of crystallites calculated from XRD patterns was from 20 to 31 nm for cubic ZnSe prepared with ZnCl2. For ZnSe synthesized with phthalic acid the crystallite size ranged from 16 to 73 nm. Size, phase composition, morphology, and crystallinity of ZnSe nanoparticles were studied by transmission electron microscopy (TEM) and selected area electron diffraction (SAED). Photoluminescence spectra (PL) at room temperature have shown a broad red emission bands, and the presence of de-aggregating agent has altered the intensity of the PL signal as well.