- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Strong Exciton-Plasmon Coupling and Hybridization of Organic-Inorganic Exciton-Polaritons in Plasmonic Nanocavity <sup>*</sup>
摘要： We investigate strong exciton-plasmon coupling and plasmon-mediated hybridization between the Frenkel (F) and Wannier–Mott (WM) excitons of an organic-inorganic hybrid system consisting of a silver ring separated from a monolayer WS2 by J-aggregates. The extinction spectra of the hybrid system calculated by employing the coupled oscillator model are consistent with the results simulated by the finite-difference time-domain method. The calculation results show that strong couplings among F excitons, WM excitons, and localized surface plasmon resonances (LSPRs) lead to the appearance of three plexciton branches in the extinction spectra. The weighting efficiencies of the F exciton, WM exciton and LSPR modes in three plexciton branches are used to analyze the exciton-polaritons in the system. Furthermore, the strong coupling between two different excitons and LSPRs is manipulated by tuning F or WM exciton resonances.
关键词： coupled oscillator model,finite-difference time-domain method,localized surface plasmon resonances,plasmonic nanocavity,exciton-plasmon coupling,Frenkel excitons,organic-inorganic hybrid system,Wannier–Mott excitons
更新于2025-09-23 15:21:01
-
Effects of near-field electromagnetic coupling in dimers of nanoparticles with a silver core and a J-aggregate dye shell
摘要： We report a theoretical study of the plasmon – exciton coupling effect on the absorption spectra of pairs of closely spaced double-layer hybrid nanoparticles consisting of a metallic core and a J-aggregate dye shell. The effect of frequency conversion of plasmonic lines due to the near-field interaction between plasmons and Frenkel excitons of the organic shell is demonstrated. The effect leads to the appearance of additional spectral lines in the long-wavelength part of the spectrum of the system of hybrid particles. The shapes and the relative intensities of the additional lines exactly reproduce the specific features of the original spectrum of plasmonic absorption bands in uncoated metallic nanoparticles. The discovered phenomenon can be used to design new types of high-sensitivity nanosensors, based on plasmon – exciton effects and principles of near-field optics.
关键词： near-field electromagnetic coupling,nanophotonics,Frenkel excitons,dimers of metalorganic nanoparticles,plasmon – exciton interaction,molecular J-aggregates,localised plasmons,absorption spectra
更新于2025-09-19 17:15:36
-
Simulations of Frenkel to Wannier-Mott-Exciton Transitions in a Nano-Hybrid System
摘要： Excitation energy transfer at a prototypical organic/inorganic interface is described theoretically. The nano-hybrid system to be investigated is built up by a vertical stacking of 20 para-sexiphenyl molecules physisorbed on a ZnO nano-crystal of 3903 atoms. To determine the time scale of excitation energy transfer all relevant electronic excitations of the organic and inorganic part are computed together with the related excitation energy transfer couplings. Values of the coupling lie in the meV-range or less. This motivates a Golden Rule description of the excitation energy transfer. Different Frenkel excitons are chosen as excitation energy donor levels. Due to the H-aggregate configuration of the organic part the number of exciton wave function nodes increases with decreasing exciton energy. As a result, the couplings of the individual molecules to a certain ZnO electron-hole pair cancel each other more intensively and the overall transfer rate gets smaller. The highest exciton levels decay most rapidly and are characterized by lifetimes in the ps-region. The lower part of the exciton band, however, has lifetimes in the ns-region. The Golden Rule description is finally compared to a direct solution of the time-dependent Schroedinger equation. The obtained transfer dynamics confirm those of the rate equation approach when the higher part of the Frenkel exciton band is considered. In the lower part the reduced number of final electron-hole pair states in the inorganic part blocks the Frenkel-exciton decay.
关键词： nano-hybrid system,Golden Rule,Frenkel excitons,time-dependent Schroedinger equation,Wannier-Mott excitons,Excitation energy transfer
更新于2025-09-11 14:15:04
-
Dynamics of Frenkel Excitons in Pentacene
摘要： The dispersion relation for noninteracting excitons and the in?uence of perturbative corrections are examined in the case of pentacene structure. The values of exchange integrals are determined by nonlinear ?ts to the experimental dispersion data, obtained by the inelastic electron scattering reported in recent experiments. We obtain theoretical dispersion curves along four different directions in the Brillouin zone which possess the same periodicity as the experimental data. We also show that perturbative corrections are negligible since the exciton gap in the dispersion relation is huge in comparison to the exchange integrals.
关键词： exciton-exciton interactions,effective ?eld theory,Heisenberg model,Frenkel excitons
更新于2025-09-10 09:29:36