Novel synthesis of selective phase-shape orientation of AgInS₂ nanoparticles at low temperature

In this work, phase- and shape-controlled AgInS₂ (AIS) colloidal nanoparticles are synthesized by thermal decomposition of metal xanthate at a temperature of ~110 °C in an organic solvent containing surfactant molecules. The spherical tetragonal-shaped AIS was observed when o-dichlorobenzene (DCB) with oleylamine (OLA) and trioctylphosphine (TOP) was used, while rod-shaped AIS with orthorhombic structure was observed in the presence of o-dichlorobenzene with pyridine (PY). The resulting nanoparticles are analyzed by X-ray diffraction (XRD), UV-vis, PL, Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM) techniques. It is also reported that the AIS nanoparticles (NPs) synthesized in the presence of OLA and TOP show a photoluminescence properties, and their fluorescence emission wavelength can readily be tuned from the ultraviolet (UV) to the visible spectrum region by merely prolonging the reaction time.