Carrier dynamics in silver nanoclusters

Categories: Ultrafast Laser Spectroscopy

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FigLS_6-1

Figure 1: An increase in PL quantum yield of Ag29 nanoclusters by its doping with a number of Au atoms (top panel). Schematic representation which reveals the involvement of two mechanisms by which MV2+ induces the decay of the excited state of Ag29 NCs through static and diffusion-controlled electron transfer (bottom panel).​

Very recently, we extended our research activities using the state-of-the-art laser spectroscopy to newly synthesized silver nanoclusters. We accomplished a ≥26-fold photoluminescence (PL) quantum yield enhancement of the Ag29 nanoclusters by its doping with a discrete number of Au atoms, producing Ag29-xAux x=1-5 (see Figure 1, top panel). The Au-doped clusters exhibit enhanced stability, long excited state lifetime and an intense red emission at ~660 nm. We took an important step forward by studying the charge transfer dynamics at these Ag29 nanoclusters-molecular acceptor interfaces. In other works, we present the light-harvesting capability of Ag29 nanoclusters using both fs-ns TA spectroscopy. We found that these new clusters can serve as a promising absorber layer in UV-Vis regions with very rapid and efficient electron injection to the molecular acceptor MV2+. Perhaps more importantly, our time-resolved data reveals the involvement of two mechanisms by which MV2+ induces the decay of the excited state of Ag29 NCs through static and diffusion-controlled electron transfer (Figure 1, lower panel).