Synthesis and Characterization of Ultrathin Silver Sulfide Nanoplatelets

We report the synthesis of ultrathin, silver sulfide (Ag 2 S) nanoplatelets (NPLs) synthesized via a one-pot method in ethylene glycol with 3-mercaptopropionic acid serving as both the sulfur precursor and platelet ligand.The colloidally synthesized nanoplatelets are exceptionally thin, with a thickness of only 3.5±0.2Å, and a 1S exciton Bohr diameter to confinement ratio of ∼12.6.The NPL growth is shown to be quantized by layer thickness using absorption and photoluminescence (PL) spectroscopy.Transmission electron microscopy (TEM), atomic force microscopy (AFM), and x-ray diffraction analyses of the NPLs show that they correspond to the (202) plane of the β-Ag 2 S structure.The PL quantum yield of these NPLs is ∼30% suggesting their potential use in biomedical imaging.Optoelectronic properties were evaluated via sensitized photocurrent spectroscopy with the resulting spectra closely matching the distinctive absorption spectral shape of the Ag 2 S NPLs.