Enhancing the Photoluminescence of SnS Quantum Dots by ZnS Treatment

Abstract Near-infrared, nontoxic SnS quantum dot has been shown to be a good bioimaging probe. It was found that surface treatment by ZnS precursor solution improved the photoluminescence of the SnS by 19x without changing the emission wavelength. EDS and XPS showed that small amounts of ZnS was present on the surface of SnS particles, while TEM showed that the ZnS treatment caused the SnS particles to cluster leading to a redshift in the UV/Vis absorption spectra and the sharpening of XRD peaks. The suspension stability of the SnS/ZnS quantum dots was further improved with 3-Mercaptopropionic acid as a capping molecule.