Light Emission from Vibronic Polaritons in Coupled Metalloporphyrin-Multimode Cavity Systems

In this study, we explore how one can use cavity polariton formation and a non-Condon vibronic coupling mechanism to form a type of hybrid light-matter state we denote asHerzberg-Teller (HT) vibronic polaritons. We use simple models to define the basiccharacteristics of these hybrid light-matter excitations including their dispersive energies.Experimentally, wefind evidence of HT polaritons in the light emission spectra from copper(II)tetraphenylporphyrin (CuTPP) molecules strongly coupled to both single and multimodeFabry-Perot resonator structures. For specific resonator designs, wefind evidence of significantenhancement of light emission from a short-lived sing-doublet state of CuTPP, which couples toa higher energy singlet state via a non-Condon vibronic mechanism. The results of a two-statemodel support the conclusion that this enhancement and the temperature-dependent dispersionof the light emission peak energy stem from radiative relaxation into cavity photon states dressedby collective vibrations of the molecules participating in polariton formation. These results showhow researchers can leverage the complex interplay of electronic and nuclear degrees of freedomin light absorbing molecules to form a vaster array of coherent light-matter states and potentially transform platforms inoptoelectronic and photocatalytic technologies