Hydrothermal synthesis of bright and stable AgInS2 quantum dots with tunable visible emission

Highly luminescent AgInS2 quantum dots (AIS QDs) were synthesized via hydrothermal method using L-glutathione (GSH) and sodium citrate (SC) as ligands. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) results confirmed that the AIS QDs have tetragonal chalcopyrite structure with good crystallinity, and the average diameter was about 3-5 nm. In addition, the obtained AIS QDs exhibited tunable photoluminescence (PL) spectra ranging from 575 nm to 650 nm and the quantum yield (QY) could reach up to 21.6% with the Ag/In ratio of 1: 4 without further processing. Moreover, the experimental results demonstrated that the AIS QDs had long fluorescence lifetimes and excellent storage stability, indicating their promising applications in light-emitting diode (LED) and biological imaging fields.