Figure 1

(a) The ground state absorption spectra for solutions of the monomer (${\mathrm{TSPP}}^{4-}$) and the $J$ aggregate (${\mathrm{TSPP}}^{2-}$). The molecular structure of the ${\mathrm{TSPP}}^{4-}$ monomer is shown in the inset. (b) The plasmon-exciton hybrid dispersion curve for the ${\mathrm{TSPP}}^{2-}$ $J$ aggregate on a Ag film.Reuse & Permissions

Figure 2

(a) The pump-probe ATR geometry used for a selective SPP excitation via the probe pulse. (b) Control geometry which does not allow for the probe to directly excite SPPs (c) $S_2$ transient kinetics obtained for a probe-induced plasmon energy at 1.87 ev for the ATR geometry (black circles) and for the control geometry (gray circles) with a vertical offset for clarity. The solid curves are multiexponential fits with characteristic decay times of 370 fs, 4.9 ps, 150 ps, and 1.7 ns, and amplitudes as outlined in the text. The data for the control geometry do not have a sub-ps decay for any angle of incidence. The inset shows the full, long time decay of the $S_2$ kinetics. (d) The amplitudes as a percentage of total $\Delta A$ of the 370 fs and 4.9 ps components as a function of the SPP energy excited by the probe pulse.Reuse & Permissions

Figure 3

Transient absorption spectrum of ${\mathrm{TSPP}}^{2-}$ $J$ aggregates at 1.5 ps delay for an excitation at 2.50 ev. (a) Spectrum in solution. (b)–(d) Spectra of the hybrid structure in the ATR pump-probe geometry for three SPP energies excited by the probe.Reuse & Permissions

Figure 4

Relaxation pathways when the SPP overlaps (a) the $S_1$ exciton or (b) the $S_2$ exciton. The process is analogous to an ultrafast all-optical transistor controlling the energy flow from $S_2$ to $S_1$ via SPP gating. The transistor is in its ON state for case (a) and OFF state for case (b).Reuse & Permissions