Magnetic fields are uniquely valuable for creating colloidal nanostructured materials, not only providing a means for controlled synthesis but also guiding their self‐assembly into distinct superstructures. In this study, a magnetothermal process for synthesizing hybrid nanostructures comprising ferrimagnetic magnetite nanorods coated with fluorescent perovskite nanocrystals is reported and their magnetic assembly into superstructures capable of emitting linear and circularly polarized light are demonstrated. Under UV excitation, the superstructures assembled in a liner magnetic field produce linear polarized luminescence, and those assembled in a chiral magnetic field exhibit strong circularly polarized luminescence (CPL) with a
- Award ID(s):
- 1748529
- NSF-PAR ID:
- 10397773
- Date Published:
- Journal Name:
- Advanced Materials
- ISSN:
- 0935-9648
- Page Range / eLocation ID:
- 2108431
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
Abstract g lumvalue up to 0.44 (±0.004). The CPL is believed to originate from the dipolar interaction between neighboring perovskite nanocrystals attached to the chiral assemblies and the chiral‐selective absorption of the perovskite emission by the magnetite phase. The magnetic synthesis and assembly approaches and the resulting distinctive chiral superstructures are anticipated to open up new avenues for designing diverse functional chiroptical devices. -
Abstract The transfer of structural mirror asymmetry from chiral molecules to the inorganic phase at solid‐liquid interfaces enabled rapid development of biomimetic chiral nanoparticles. They can be synthesized and assembled following a variety of chemical methods resulting in the broad family of chiral inorganic nanostructures (CNs). Their chemistry attracted large attention due to marked enhancement of circular dichroism and polarization rotation compared to organic molecules and particles, which opened application prospects in sensing, imaging, catalysis, nonlinear optics, electronics, and medicine. New physical, chemical and biological effects involving CNs such as giant optical activity, mechanical force‐assisted modulation of optical activity, photon‐to‐particle chirality transfer and suppression of amyloid toxicity have been observed. Marked strides toward enhancement of optical asymmetry (
g ‐factor), engineering dynamic chirality in nanostructures, and spectral range of optical activity of chiral inorganic nanostructures from the ultraviolet to terahertz regions have also been made. Here, we summarize these and other current trends in the research of chiral inorganic nanomaterials and offer our perspective how the fundamental and translational research in this area is likely to develop in the next two decades. -
Abstract Optical chirality is an effective means in screening molecules and their enantiomers in bioengineering, and recently has garnered attention as an implementation of qubits in quantum information processing. The conventional detection of circularly polarized light (CPL) is based on phase retardation and polarization separation using multiple optical components. An intrinsic solid‐state chirality detection device would be favorable for easier integration and implementation. Optical spin injection to the spin‐momentum‐locked topological surface states of topological insulators (TIs) by circularly polarized light leads to a directional DC photocurrent and hence possible circular polarization detection. However, this DC photocurrent is also accompanied by other photo‐responses. Here, a photodetection strategy using a TI transistor which senses CPL without the use of any additional components is demonstrated, it achieves a uniform response over the entire device with a sensitivity ≈5.6%. The Stokes parameters can also be extracted by arithmetic operation of photocurrents obtained with different bias and gate for a complete characterization of a polarized light beam. Therefore, this method enables chirality detection and Stokes parameter analysis using a single device. The proposed miniaturized intrinsic chirality detectors facilitate polarimetry sensing in applications from circular dichroism spectroscopy to biomedical diagnosis.
-
Abstract Natural polymers, particularly plant‐derived nanocelluloses, self‐organize into hierarchical structures, enabling mechanical robustness, bright iridescence, emission, and polarized light reflection. These biophotonic properties are facilitated by the assembly of individual components during evaporation, such as cellulose nanocrystals (CNCs), which exhibit a left‐handed helical pitch in a chiral nematic state. This work demonstrates how optically active films with pre‐programmed opposite handedness (left or right) can be constructed via shear‐induced twisted printing with clockwise and counter‐clockwise shearing vectors. The resulting large‐area thin films are transparent yet exhibit pre‐determined mirror‐symmetrical optical activity, enabling the distinction of absorbed and emitted circularly polarized light. This processing method allows for sequential printing of thin and ultrathin films with twisted layered organization and on‐demand helicity. The complex light polarization behavior is due to step‐like changes in linear birefringence within each deposited layer and circular birefringence, different from that of conventional CNC films as revealed with Muller matrix analysis. Furthermore, intercalating an achiral organic dye into printed structures induces circularly polarized luminescence while preserving high transmittance and controlled handedness. These results suggest that twisted sequential printing can facilitate the construction of chiroptical metamaterials with tunable circular polarization, absorption, and emission for optical filters, encryption, photonic coatings, and chiral sensors.
-
Abstract Metasurfaces composed of in‐plane subwavelength nanostructures have unprecedented capability in manipulating the amplitude, phase, and polarization states of light. Here, a unique type of direction‐controlled bifunctional metasurface polarizer is proposed and experimentally demonstrated based on plasmonic stepped slit‐groove dimers. In the forward direction, a chiral linear polarizer is enabled which only allows the transmission of a certain incident handedness and converts it into the specified linear polarization. In the backward direction, the metasurface functions as an anisotropic circular polarizer to selectively convert a certain linear polarization component into the desired circularly polarized transmission. The observed direction‐controlled polarization selection and conversion are explained by the spin‐dependent mode coupling process inside the bilayer structure. Anisotropic chiral imaging based on the proposed metasurface polarizer is further demonstrated. The results provide new degrees of freedom to realize future multifunctional photonic integrated devices for structured light conversion, vector beam generation, optical imaging and sensing, and optical communication.