Laser displays, benefiting from the characteristic merits of lasers, have led to the revolution of next-generation display technologies owing to their superior color expression. However, the acquis... Description

Exciton–polariton Bose–Einstein condensation (EP BEC) is of crucial importance for the development of coherent light sources and optical logic elements, as it creates a new state of matter with coherent nature and nonlinear behaviors. The demand for room temperature EP BEC has driven the development of organic polaritons because of the large binding energies of Frenkel excitons in organic materials. However, the reliance on external high-finesse microcavities for organic EP BEC results in poor compactness and integrability of devices, which restricts their practical applications in on-chip integration. Here, we demonstrate room temperature EP BEC in organic single-crystal microribbon natural cavities. The regularly shaped microribbons serve as waveguide Fabry–Pérot microcavities, in which efficient strong coupling between Frenkel excitons and photons leads to the generation of EPs at room temperature. The large exciton–photon coupling strength due to high exciton densities facilitates the achievement of EP BEC. Taking advantages of interactions in EP condensates and dimension confinement effects, we demonstrate the realization of controllable output of coherent light from the microribbons. We hope that the results will provide a useful enlightenment for using organic single crystals to construct miniaturized polaritonic devices.

Thermo-responsive light-emitting materials have wide potential applications in temperature sensing, bioimaging, optoelectronic devices and information security, due to their intriguing luminescence property changes in response to temperature. Among them, light-emitting metal complexes and related coordination materials are appealing in possessing enormous structural diversity and excellent luminescence properties. The general thermo-responsive types and the underlying mechanism of these materials and recent progress in the development of thermo-responsive metal complexes and related materials are surveyed in this critical review, including small molecular metal complexes with different electronic configurations (d⁶, d⁸, d¹⁰, among others), metal clusters, coordination polymers, metal–organic frameworks (MOFs), and multicomponent coordination polymers and assemblies. A particular focus is given on how to build systems showing ratiometric lumunescence changes in response to temperature, including molecular dyads containing two chromophores, heterodimetallic clusters, mixed-metal MOFs, and energy donor–acceptor assemblies. In addition, the applications of these materials in temperature sensing, bioimaging, and information security are briefly discussed. A perspective is given in the Conclusion section to reflect potential guidelines for future research in this field.

Atomically thin plasmonic MoO₂ nanosheets were successfully obtained via a solid–solid reaction, which exhibits tremendous potential for the general fabrication of other two-dimensional nonlayered materials.

Information encryption and decryption have attracted particular attention; however, the applications are frequently restricted by limited coding capacity due to the indistinguishable broad photoluminescence band of conventional stimuli-responsive fluorescent materials. Here, we present a concept of confidential information encryption with photoresponsive liquid crystal (LC) lasing materials, which were used to fabricate ordered microlaser arrays through a microtemplate-assisted inkjet printing method. LC microlasers exhibit narrow-bandwidth single-mode emissions, and the wavelength of LC microlasers was reversibly modulated based on the optical isomerization of the chiral dopant in LCs. On this basis, we demonstrate phototunable information authentication on LC microlaser arrays using the wavelength of LC microlasers as primary codes. These results provide enlightenment for the implementation of microlaser-based cryptographic primitives for information encryption and anticounterfeiting applications.