Lyotropic liquid crystalline phases of anisotropic nanoparticles of organic-inorganic metal halide perovskites: photoluminescence from self-assembled ordered microstructures of semiconductors.

Abstract

A simple method (which could be completed within 60 minutes at 298 K) was developed to transform layered organic-inorganic metal halide perovskites into colloidal lyotropic liquid crystalline dispersions with microscopic structural orderliness as well as semiconducting properties and photoluminescence. Experimentally, hexagonal-shaped mesogenic nanoplatelets of two-dimensional lead iodide perovskites (R-NH3)2PbI4 were synthesized by antisolvent-induced rapid microcrystallization and stabilized by surfactants, and self-assembled into discotic-nematic phases with optical anisotropy and greenish-blue fluorescence. Combining the stimuli-responsive, light-interactive, and reconfigurable ordered structures of liquid crystals with the adjustable semiconductivity of hybrid perovskites, these photoluminescent soft anisotropic materials may be used for polarized light emission or detection.