Superradiance Emission and Its Thermal Decoherence in Lead Halide Perovskites Superlattices

Self-assembled nanocrystals (NCs) into superlattices (SLs) are alternative materials to polycrystalline films and single crystals, which can behave very differently from their constituents, especially when they interact coherently with each other. This work concentrates on the Superradiance (SR) emission observed in SLs formed by CsPbBr3 CsPbBrI2 NCs. Micro-Photoluminescence spectra transients temperature range 4–100 K measured extract information about SR states uncoupled domains of For mostly homogeneous lines (linewidth 1–5 meV), this measures lifetimes as short 160 ps, 10 times lower than value a thin film made same NCs, is due near identical NCs 1000 40 000 coupled dipole–dipole interaction. The thermal decoherence exciton state evident above 25 its coupling an effective phonon energy ≈8 meV. These findings important step toward understanding enhancement factor dephasing process perovskite SLs.