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A technique of obtaining plexitonic structures based on Ag 2 S quantum dots passivated with l-cysteine (Ag 2 S/l-Cys QDs) in the presence of Au nanorods passivated with cetyltrimethylammonium bromide molecules (Au/CTAB NRs) with controlled luminescence properties has been developed. The structural and luminescence properties of Ag 2 S/l-Cys QDs with Au/CTAB NRs are studied. The effect of plasmonic Au/CTAB NRs on IR trap state luminescence (750 nm) is considered. It has been found that the direct interaction between the components of the plexcitonic nanostructure leads to a significant luminescence quenching of Ag 2 S/l-Cys QDs, with the luminescence lifetime being constant. This is the evidence for photoinduced charge transfer. The spatial separation of the components of plexcitonic nanostructures due to the introduction of a polymer - poly(diallyldimethylammonium chloride) (polyDADMAC) provides a means to change their mutual arrangement and achieve an increase in the IR trap state luminescence intensity and a decrease in the luminescence lifetime from 7.2 ns to 4.5 ns. With weak plexcitonic coupling in the nanostructures [Ag 2 S QD/l-Cys]/[polyDADMAC]/[Au/CTAB NRs], the possibility of increasing the quantum yield of trap state luminescence for Ag 2 S QDs due to the Purcell effect has been demonstrated. In the case of formation [Ag 2 S QD/l-Cys]/[polyDADMAC]/[Au/CTAB NRs] a transformation of shallow trap state structure was established using the thermostimulated luminescence method., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this paper, we present the results on photoinduced formation of colloidal Ag 2 S quantum dots with sizes of 1.5-3 nm passivated by 2-mercaptopropionic acid (Ag 2 S/2-MPA) in the presence of ethylene glycol. The synthetized colloidal Ag 2 S/2-MPA QDs have NIR recombination luminescence with its maximum near 800 nm. The control of absorption and luminescence properties of the QDs is achieved by photoactivation. It is shown that photoexposure of colloidal solution of Ag 2 S/2-MPA QDs leads to an increase in the QD size and monodispersity along side with the growth of the luminescence quantum yield from 1% to 7.9%. Enhancement of the luminescence quantum yield is accompanied by an increase in the average luminescence lifetime up to 190 ns, which is due to the blocking of the nonradiative recombination channel with the radiative recombination rate being (3-5.5) × 10 5 s -1 . It is shown that the purification of the Ag 2 S/2-MPA solution by a dialysis membrane from regenerated cellulose leads to an increase in the sample monodispersity, as well as stops the photoinduced growth of QDs, and also reduces the degradation of their photoluminescence., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)