Exciton-Polariton Properties in Planar Microcavity of Millimeter-Sized Two-Dimensional Perovskite Sheet.

In this work, the self-organized two-dimensional (2D) perovskite crystal sheet was synthesized for exciton-polariton studies. The layered 2D perovskite sheets naturally form Fabry-Pérot (F-P) optical cavities and exhibit evident cavity polariton modes. In the region of F-P cavity polariton modes, an exciton-polariton is formed by the superposition of strongly coupled exciton and photon states and the decreased spacing between two adjacent oscillation modes can be well explained by the formation of exciton polarities. Rabi splitting energy (Ω) evaluated from the energy-wavevector (E-k) dispersion relation of exciton-polariton coupling was about 259 ± 10 meV. For edge emissions of the laminated structure, the thickness-dependent quantum well exerts great influence on the band-gap absorption and emission. This work studies exciton-polariton properties in layered 2D perovskite sheets, making it possible application for polariton devices in the strong light-matter interaction region.