Perovskite Bulk Crystals Grown through Antisolvent Droplet-Assisted Crystallization and Associated Wavelength-Dependent Photoluminescence Dynamics

Perovskite bulk crystals (BCs) have been generally synthesized and grown via the temperature-mediated processes. Here, we report a facile strategy of using antisolvent droplets for assisting the crystallization and growth of large high-quality perovskite BCs (∼5 mm) at room temperature. The formation of either CsPbBr3 or Cs4PbBr6 BCs was controllable through tuning the composition of solvents used during growth. Such high-quality as-grown BCs were chosen for demonstrating the carrier–lattice interactions under photoexcitation operation. The wavelength-dependent time-resolved photoluminescence dynamics revealed that both the blue-side and red-side "solvation-like" effect between the photocarriers and surrounding lattices existed in the BCs, whereas only the blue-side one was obviously observed in the nanocrystals. The antisolvent droplet-assisted crystallization offers a versatile strategy of growing perovskite BCs with tunable compositions, and the distinct solvation behaviors enrich a fundamental understanding of photocarrier energy relaxations in perovskites with nanoscale and bulk forms.