Fig. 1: Tuning structural and chemical properties through ultrafast laser irradiation.
From: Ultrafast photochemistry produces superbright short-wave infrared dots for low-dose in vivo imaging
a HAADF-STEM micrograph of the as-synthesized Ag2S dots. Scale bar is 10 nm. b High-resolution STEM of as-synthetized dots showing lattice fringes d111 and d−104 of cubic Ag and monoclinic Ag2S, respectively. 2D EDS mapping of the spatial distribution of Ag (c), S (d), and Ag+S (e). f Magnified STEM micrograph of two Ag2S dots. g Net X-ray intensity profiles extracted from the green arrow marked in f. Note how the Ag/S ratio increases at the edges of the dots, which coincides with the electro-dense area. The inset shows a model Ag2S dot. h HAADF-STEM micrograph of Ag2S dots after ultrafast laser irradiation with 50 fs laser pulses for 90 min at a power density of 9 W cm−2. Scale bar is 10 nm. i High-resolution STEM of an ultrafast laser-irradiated Ag2S dot showing lattice fringes d111 and d110 of cubic Ag and monoclinic Ag2S, respectively. Note the presence of a shell marked with a blue bracket around the nanoparticle. 2D EDS mapping of the spatial distribution of Ag (j), S (k), Cl (l), and Ag+S + Cl (m) of an ultrafast laser-irradiated Ag2S dot. n Magnified STEM micrograph of an ultrafast laser-irradiated Ag2S dot. o Net X-ray intensity profiles extracted from the green arrow marked in image (n), where we can observe the presence of Ag, S, and Cl. The inset in o shows a schematic representation of a single Ag2S dot after ultrafast laser irradiation.
