Abstract
Thioglycolic acid (TGA)-coated colloidal Ag2S quantum dots (QDs) emitting in the near-infrared (NIR) region upon excitation by an 808 nm diode laser were synthesized. The observed photoluminescence (PL) was attributed to the presence of ligand-modified Ag2S on the QD surfaces and could be easily controlled by a simple dilution process due to the concentration-dependent surface structure of the colloidal QDs. Upon dilution of the solution, the PL intensity initially increased before later decreasing, with a blueshift being observed in the PL spectra. These phenomena can be accounted for by the aggregation of QDs due to a decrease in the content of ligand-modified Ag2S on the QD surfaces upon dilution, which in turn affected the fluorescence resonance energy transfer (FRET), and re-emission of the surface energy level.
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Zhang, Y., Xia, J., Li, C. et al. Near-infrared-emitting colloidal Ag2S quantum dots excited by an 808 nm diode laser. J Mater Sci 52, 9424–9429 (2017). https://doi.org/10.1007/s10853-017-1131-5
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DOI: https://doi.org/10.1007/s10853-017-1131-5