Fig. 1. (a) Schematic diagram of the hybrid of Ag nanoprisms and Ag@Au HNS embedded in an ensemble of J-aggregate (TDBC). (b) The structural formula of a TDBC molecule.

Fig. 2. TEM images of (a) Ag NPs, (b) Ag@Au HNS, (c) Ag NPs/TDBC, and (d) Ag@Au HNS/TDBC. (e) and (g) Mapping of elements (distribution of Ag/Au element) of Ag NPs and Ag@Au HNS. (f) and (h) STEM images of Ag NPs and Ag@Au HNS. (i) The energy dispersive X-ray spectroscopy (EDX) analysis of Ag@Au HNS.

Fig. 3. (a) Ultraviolet-visible absorption spectrum of TDBC dye molecules. (b) Ultraviolet-visible absorption spectra of four nanostructures (black line indicates Ag NPs, red line indicates Ag@Au HNS, blue line indicates Ag NPs/TDBC, and green line indicates Ag@Au HNS/TDBC).

Fig. 4. (a) Fluorescent spectra of Ag NPs/TDBC and Ag@Au HNS/TDBC. (b), (c) Temperature-dependent fluorescence intensity curves of Ag NPs/TDBC and Ag@Au HNS/TDBC measured at T = 100–300 K.

Fig. 5. Electric field (|E/E₀|) distribution images for the (a) pure Ag individual NP with LSPR peak at 565 nm, (b) TDBC-doped Ag NPs ensemble with LSPR peak at the upper branch (ω₊) maximum (544 nm), (c) TDBC-doped Ag NPs ensemble with LSPR peak at the minimum (577 nm), (d) J-aggregate-doped Ag NPs ensemble with LSPR peak at the lower branch (ω₋) maximum (607 nm), (e) Ag@Au HNS individual nanoparticle with LSPR peak at 589 nm, (f) TDBC-doped Ag@Au HNS ensemble with LSPR peak at the upper branch (ω₊) maximum (559 nm), (g) TDBC-doped Ag@Au HNS ensemble with LSPR peak at the minimum (583 nm), and (h) J-aggregate-doped Ag@Au HNS ensemble with LSPR peak at the lower branch (ω₋) maximum (612 nm). (i) Simulation extinction spectra of four nanostructures (black line indicates Ag NPs, red line indicates Ag@Au HNS, blue line indicates Ag NPs/TDBC, and green line indicates Ag@Au HNS/TDBC).