Room-temperature strong light-matter coupling and polariton condensation in perovskite materials

Strong light-matter coupling have been reported in a wide range of organic and inorganic semiconductors, while the demonstrations of the polariton condensation and the subsequent polariton lasing are still limited within a handful of semiconductors at both low and room temperatures. Recent progress on halide perovskites, particularly the all-inorganic perovskite, suggested an alternative optical gain materials towards strong light-matter coupling operated at room temperature due to large exciton binding energy, large oscillator strength and facile synthesis. In this talk, I will first present our results on synthesis of high quality hybrid perovskite materials and their excellent optical gain properties, then I will present our recent demonstration of polariton lasing and polariton Bose-Einstein condensate at room temperature in CsPbCl3 nanoplatelets embedded in a planar microcavity. These effects are unambiguously evidenced in the blue region of the visible spectrum by superlinear power dependence, macroscopic ground state occupation, blueshift of the ground state emission, narrowing of the linewidth and build-up of long-range spatial coherence. Next, I will present our latest results on room-temperature strong light-matter coupling in CsPbBr3 nanowires embedded in a planar microcavity, whereby a polariton emission characterized by the typical polariton dispersion in laterally confined nanostructures is clearly evidenced in the green region of the visible spectrum. Polariton condensate ultrafast propagation can be further realized in such 1D microcavity. Our research advocates the considerable promise of perovskite materials for room temperature polaritonics applications, for instance ultrafast polaritonics and electrically driven polariton laser.