Direct detection of circularly polarized light (CPL) is a challenging task due to limited materials and ambiguous structure–property relationships that lead to low distinguishability of the light helicities. Perovskite ferroelectric semiconductors incorporating chirality provide new opportunities in dealing with this issue. Herein, a pair of 2D chiral perovskite ferroelectrics is reported, which have enhanced CPL detection performance due to interplays among lattice, photon, charge, spin, and orbit. The chirality‐transfer‐induced chiral&polar ferroelectric phase enhances the asymmetric nature of the photoactive sublattice and achieves a switchable self‐powered detection via the bulk photovoltaic effect. The single‐crystal‐based device exhibits a CPL‐sensitive detection performance under 430 nm with an asymmetric factor of 0.20 for left‐ and right‐CPL differentiation, about two times that of the pure chiral counterparts. The enhanced CPL detection performance is ascribed to the Rashba–Dresselhaus effect that originates from the bulk inversion asymmetry and strong spin–orbit coupling, shown with a large Rashba coefficient, which is demonstrated by density functional theory calculation and circularly polarized light excited photoluminescence measurement. These results provide new perspectives on chiral Rashba ferroelectric semiconductors for direct CPL detection and ferroelectrics‐based chiroptics and spintronics.

Ferroic phase transition molecular crystals (FPTMCs), i.e., ferroelectrics and ferroelastics, are an important family of functional molecular materials, having merits of easy synthesis, structural tunability and flexibility, and biocompatibility. Both...

Functional dynamic molecular crystals have drawn increasing interest in exploring next-generation flexible and smart materials. Molecular rotors, as a typical type of dynamic materials, are good candidates to exhibit bulk...

Metal-halide perovskites have been extensively investigated due to their fascinating structural diversity and outstanding optoelectronic properties. We report the photoluminescence and photoelectric response behavior of a nontypical Dion–Jacobson perovskite [(4AMTP)PbBr2]2PbBr4 (4AMTP = 4-aminomethyltetrahydropyran cation), featuring neutral PbBr2 layers incorporated into the cationic layers between the anionic [PbBr4]2– layers. A 4AMTP-coordinated PbBr2 unit constitutes the unique nontypical dication layer. The seven-coordinated PbBr6O unit forms a largely distorted decahedron with a short distance from the inorganic [PbBr4]2– layer. The photoluminescence behavior of [(4AMTP)PbBr2]2PbBr4 shows crystal size dependence. Larger crystals show purplish-blue emission with two peaks at 414 and 431 nm, whereas smaller grain size (<50 μm) crystals demonstrate a single emission peak at 425 nm. Meanwhile, it shows a blue-light photoelectric response under the illumination of 405 nm with an on/off ratio of 175 for single-crystal devices and 97 for thin-film devices. The photoresponse performance is proportional to the molar extinction coefficient of the absorption band edge.

Martensitic transformation, usually accompanied by ferroelastic and thermoelastic behaviors, is an interesting and useful mechanical-related property upon external stimuli. For molecular crystals, however, martensitic systems to show reversible stimuli-actuation behaviors are still limited because of a lack of designability and frequent crystal collapse due to large stress releases during the transformations. Here, a one-dimensional hybrid perovskite semiconductor (NMEA)PbI3 (NMEA = N-methylethylammonium) was prepared by following a dimensionality reduction design principle. The crystal undergoes reversible ferroelastic and thermoelastic martensitic transformations, which are attributed to weak intermolecular interactions among the chains that easily trigger the interchain shearing movement. The actuation behavior occurring during the phase transition is very close to room temperature and demonstrated to behave as a mechanical actuator for switching. This work provides an effective approach to designing molecular actuators with promising applications in next-generation intelligence devices.