Exciton-plasmon couplings in plexcitonic CuCl-Ag nanoshells: Rabi splitting and induced transparency

摘要

The plasmon-exciton couplings in a Ag nanoshell with a semiconductor CuCl core (CuCl-Ag) have been studied theoretically. By changing the geometry of the CuCl-Ag nanoshell, the antisymmetric dipole mode (ω_(+|1)) in the outer Ag shell can be tuned through the exciton resonance (ωe) of the inner CuCl core. For a small CuCl core, the strong plasmon-exciton couplings between the ω_(+|1) and ωe modes can induce two new plexcitonic modes. A splitting energy between the plasmon and exciton of about 85 meV is obtained for the CuCl-Ag nanoshell. Furthermore, it is found that the plasmon-exciton induced transparency can be realized in the CuCl-Ag nanoshell with a large inner CuCl core, which results from the destructive interference between the broad ω_(+|1) peak and the sharp ωe peak.