Luminescent Ag-doped In2S3 nanoparticles stabilized by mercaptoacetate in water and glycerol

Brightly luminescent colloidal Ag–In–S nanoparticles stabilized in aqueous solutions by branched polyethyleneimine

“…2b) typical rather for the radiative recombination of charge carriers captured by the "deep" traps. Similar broad PL bands with a maximum energy almost coinciding with the band gap were recently observed by us for the mercaptoacetate-stabilized Ag-In-S NPs [33] and interpreted as a result of size distribution in the ensemble of colloidal particles. As the bulk In 2 S 3 is characterized by a comparatively large Bohr radius of exciton, around 30 nm [36], the Ag-In-S NPs smaller than 10 nm should be the subject of strong spatial exciton confinement and should exhibit considerable dependence of the band gap on the NP size.…”

“…We can, therefore, assume that the lighter spots on the SEM photographs reflect the presence of multiple smaller Ag-In-S NPs embedded into the PEI globules (lower-contrast areas) of ~100 nm in size. Earlier we have studied Ag-In-S NPs stabilized by mercaptoacetate ions in aqueous solutions both at Ag:In ratio lower than 1:1 [33] and the stoichiometric AgInS 2 NPs [34], where no sample charging problems occured. It has been found in [33,34] by DLS, HRTEM, SAED and XRD that the Ag-In-S NPs were 4−5 nm in size and crystallized in the tetragonal modification.…”

“…Earlier we have studied Ag-In-S NPs stabilized by mercaptoacetate ions in aqueous solutions both at Ag:In ratio lower than 1:1 [33] and the stoichiometric AgInS 2 NPs [34], where no sample charging problems occured. It has been found in [33,34] by DLS, HRTEM, SAED and XRD that the Ag-In-S NPs were 4−5 nm in size and crystallized in the tetragonal modification. We expect that the size of Ag-In-S NPs incorporated into the PEI globules is comparable with the values reported in [33,34].…”

“…It has been found in [33,34] by DLS, HRTEM, SAED and XRD that the Ag-In-S NPs were 4−5 nm in size and crystallized in the tetragonal modification. We expect that the size of Ag-In-S NPs incorporated into the PEI globules is comparable with the values reported in [33,34].…”

“…Recently we have shown feasibility of the direct synthesis of luminescent Ag-In-S NPs stabilized by mercaptoacetate anions in aqueous solutions [33,34]. The PL QY of the mercaptoacetate-stabilized Ag-In-S achieved 12% in optimized synthesis condition and can be further increased to around 30% by the deposition of a ZnS shell on the NP surface.…”