Syntheses and Optical Properties of the Water-Dispersible ZnS:Mn Nanocrystals Surface Capped by L-Aminoacid Ligands: Arginine, Cysteine, Histidine, and Methionine

Water dispersible ZnS:Mn nanocrystals were synthesized by capping the surface of the nanocrystals with four kinds of aminoacids ligands: arginine, cystein, histidine, and methionine. The arninoacids capped ZnS:Mn nanocrystal powders were characterized by XRD, HR-TEM, EDXS, and FT-IR spectroscopy. The optical properties of the aminoacids capped ZnS:Mn colloidal nanocrystals were also measured by UV/Vis and solution photoluminescence (PL) spectroscopies in aqueous solvents. The solution PL spectra showed broad emission peaks around 575 nm (orange light emissions) with PL efficiencies in the range of 4.4 to 7.1%. The measured particle sizes for the aminoacid capped ZnS:Mn nanocrystals by HR-TEM images were in the range of 5.3 to 11.7 nm.