Trapped Exciton–Polariton Condensate by Spatial Confinement in a Perovskite Microcavity

Abstract

Lead halide perovskites exhibit good performance in room-temperature exciton–polariton lasers and efficient flow of polariton condensates. Shaping and directing polariton condensates by confining the potential is essential for polariton-based optoelectronic devices, which have seldom been explored based on perovskite materials. Here, we investigate the trapping of polaritons in micron-sized CsPbBr3 flakes embedded in a microcavity by varying the negative detuning energy (from −36 to −172 meV) at room temperature. The confinement by the crystal edge results in quantized polariton states both below and above the condensed threshold. As the cavity is more negatively detuned (Δ ≤ −118 meV), the condensed polaritons undergo a transition from the ground state to metastable states with a finite group velocity (∼50 μm/ps at Δ = −118 meV). The metastable polariton condensates can be optically and stably driven between different polariton states by simply changing the pump fluence. The manipulations of the polariton states reveal the effective control of polariton relaxation in quantized polariton states by the underlying exciton–polariton and polariton–polariton scattering. Our findings pave the way for novel polaritonic light sources and integrated polariton devices through the trap engineering of perovskite microcavities.

Exciton binding energy and effective mass of CsPbCl3: a magneto-optical study

“…These outstanding results have also fueled interest on these materials in other domains. As a direct bandgap semiconductor, lead halide perovskite exhibits also excellent electronic and emission properties, very interesting for optoelectronic applications as lasers and photodiodes [4][5][6][7], photodetectors [8] or polaritonic devices [9][10][11][12][13]. In addition, the flexible synthesis of nanostructures such as nanocrystals or nanoplatelets, offers numerous opportunities for their integration in quantum devices and the development of applications in the field of quantum optics [14,16].…”

Observation of Two Thresholds Leading to Polariton Condensation in 2D Hybrid Perovskites

“…On the other hand, optical confinement phenomena take place at the position of some particular structural defects of the perovskite crystals, [ 38,39 ] similarly to what has been reported in 3D CsPbBr 3 perovskites. [ 40 ] When a defect induces a confining potential in the device plane, lasing action from multiple high‐energy confined states is observed in the real space maps ( Figure a,b) at the defect position and, as well, in the energy dispersion map (Figure 4c). Note that the lasing action from these confined states is always resonant to the defect energy band, even when varying the cavity detuning, therefore the stimulated emission can also be activated at the lowest‐energy confined state (Figures S9 and S10, Supporting Information).…”

Engineering a light–matter strong coupling regime in perovskite-based plasmonic metasurface: quasi-bound state in the continuum and exceptional points

“…Up to now, making use of perovskite platform, different groups have successfully demonstrated polariton Bose-Einstein condensation (i.e. polariton lasing) [32][33][34][35][36][37][38][39], laser cooling [40], ballistic propagation [33], exciton-surface plasmon polaritons [6,41], polaritonic microstructures [33,[42][43][44] and lattices [36,[45][46][47]. However, the polaritonic devices reported in these works are optically pumped.…”