The study investigates the dynamics of self-hybridized exciton-polaritons (E-Ps) in two-dimensional (2D) hybrid organic-inorganic perovskites (2D HOIPs). The researchers demonstrate that 2D HOIP crystals thicker than 0.5 μm on Au substrates support multiple orders of self-hybridized E-P modes, which have high Q factors (>100) and modulate the optical dispersion of the crystal, enhancing sub-gap absorption and emission. Through various spectroscopic techniques, they confirm energy transfer from higher-energy E-Ps to lower-energy E-Ps and charge transport at interfaces. The findings provide new insights into charge and energy transfer in E-Ps, opening opportunities for their manipulation in polaritonic devices. The study also explores the role of strong light-matter coupling in modifying the optical dispersion of 2D perovskite crystals and the potential for energy harvesting applications such as polaritonic photodetectors and photovoltaics.The study investigates the dynamics of self-hybridized exciton-polaritons (E-Ps) in two-dimensional (2D) hybrid organic-inorganic perovskites (2D HOIPs). The researchers demonstrate that 2D HOIP crystals thicker than 0.5 μm on Au substrates support multiple orders of self-hybridized E-P modes, which have high Q factors (>100) and modulate the optical dispersion of the crystal, enhancing sub-gap absorption and emission. Through various spectroscopic techniques, they confirm energy transfer from higher-energy E-Ps to lower-energy E-Ps and charge transport at interfaces. The findings provide new insights into charge and energy transfer in E-Ps, opening opportunities for their manipulation in polaritonic devices. The study also explores the role of strong light-matter coupling in modifying the optical dispersion of 2D perovskite crystals and the potential for energy harvesting applications such as polaritonic photodetectors and photovoltaics.