Solid‐State Photochemical Cascade Process Boosting Smart Ultralong Room‐Temperature Phosphorescence in Bismuth Halides

Abstract

Molecular ultralong room‐temperature phosphorescence (RTP), exhibiting multiple stimuli‐responsive characteristics, has garnered considerable attention due to its potential applications in light‐emitting devices, sensors, and information safety. This work proposes the utilization of photochemical cascade processes (PCCPs) in molecular crystals to design a stepwise smart RTP switch. By harnessing the sequential dynamics of photo‐burst movement (induced by [2+2] photocycloaddition) and photochromism (induced by photogenerated radicals) in a Bi‐based metal‐organic halide (MOH), a continuous and photo‐responsive ultralong RTP can be achieved. Furthermore, utilizing the same Bi‐based MOH, diverse application demonstrations, such as multi‐mode anti‐counterfeiting and information encryption, can be easily implemented. This work thus not only serves as a proof‐of‐concept for the development of solid‐state PCCPs that integrate photosalient effect and photochromism with light‐chemical‐mechanical energy conversion, but also lays the groundwork for designing new Bi‐based MOHs with dynamically responsive ultralong RTP.

Ultrastable Copper Iodide Hybrid with Intrinsic Greenish White-Light Emission by Incorporating an Anionic Inorganic Functional Unit into an Extended Structure

“…Studies have shown that the luminescence in such materials primarily arises from electron transfer processes between the organic and inorganic components. − The zero-dimensional anionic copper halide inorganic cluster motifs have been demonstrated as the important functional units for high-performance all-in-one (AIO) types of luminescent compounds. In addition, the covalent bonds between the two components provide pathways for efficient electron transfer, which is typically considered a crucial prerequisite for high luminescence efficiency of these structures.…”

Photocycloaddition of Zero-Dimensional Metal Halide Hybrids with Reversible Photochromism

“…As a kind of ionic compound, metal halide hybrids (MHHs) mainly consist of organic cations and metal halide polyhedra anions. Due to their wide composition and structure tunability, easy preparation, and excellent optical properties, MHHs have been attracted enormous attention in optoelectronic fields including X-ray scintillator, − solid-state lighting, − anticounterfeiting, − information encryption, and stimulus response. , Recently, [2 + 2] photocycloaddition was successfully employed to control the room-temperature phosphorescence switch and photochromism in zero-dimensional (0D) bibased MHHs . Endowing MHHs with reversible photochromism could significantly broaden their applications in fields such as high-level-security information encryption and optical data storage.…”

“…49,50 Recently, [2 + 2] photocycloaddition was successfully employed to control the room-temperature phosphorescence switch and photochromism in zero-dimensional (0D) bibased MHHs. 51 Endowing MHHs with reversible photochromism could significantly broaden their applications in fields such as high-level-security information encryption and optical data storage. Different from CPs and MOFs with rational structural tunability, the ionic nature of MHHs determines the poor predictability and tunability of their structures due to random assembly between organic cations and anions.…”

Modulation of Solid-State Fluorescence Properties for Anthracene Chalcone Heterocyclic Compounds by Charge-Transfer Cocrystal Self-Assembly: Molecular Stacking Mode and DFT Analysis

“…In recent years, various applications of organic crystal luminescent materials have made significant progress, such as laser sensors, photoelectron conversion, and optical signal transduction . As the key to expanding the application scope, achieving the modulation of the solid-state optical properties of the target organic molecule is challenging. − At the same time, the solid-state aggregation fluorescence quenching effect of organic molecules must also be considered to avoid strong emissivity in the dispersed state and weak or no emissivity in the aggregated state.…”