Magnetically Responsive Semiconducting Liquid Crystals of Organic–Inorganic Metal Halide Perovskites: Dynamically Reconfigurable Anisotropic Structures and Controllable Linearly Polarized Light Emission

The generation of polarized light is central to optoelectronics. While conventional polarizers inherently waste over half of the incident light energy, luminescent liquid crystals offer an efficient alternative by directly emitting polarized photons, owing to their self-assembled anisotropic superstructures. Herein, contactless and reversible magnetic orientational control was introduced into luminescent liquid crystalline materials by doping colloidal dispersions of two-dimensional nanoparticles of organic-inorganic metal halide perovskites with magnetite nanorods. The products exhibited discotic nematic ordering, tunable semiconducting bandgaps, and magnetic responsiveness. Anisotropic microdomains formed in these liquid crystals could be unidirectionally aligned along weak (0.2 t) magnetic fields from ferrite magnets, thus enabling dynamic manipulation of the polarization direction of emitted linearly polarized light. This study presents a new approach to semiconductors with structural orderliness and may guide the development of reconfigurable photonic devices.