Solely 3-Coordinated Organic-Inorganic Hybrid Copper(I) Halide: Hexagonal Channel Structure, Turn-On Response to Mechanical Force, Moisture, and Amine

Zero-Dimensional Broadband Yellow Light Emitter (TMS)3Cu2I5 for Latent Fingerprint Detection and Solid-State Lighting

We report a new hybrid organic-inorganic Cu(I) halide, (TMS)₃Cu₂I₅ (TMS = trimethylsulfonium), which demonstrates high efficiency and stable yellow light emission with a photoluminescence quantum yield (PLQY) over 25%. The zero-dimensional crystal structure of the compound is comprised of isolated face-sharing photoactive [Cu₂I₅]^3- tetrahedral dimers surrounded by TMS⁺ cations. This promotes strong quantum confinement and electron-phonon coupling, leading to a highly efficient emission from self-trapped excitons. The hybrid structure ensures prolonged stability and nonblue emission compared to unstable blue emission from all-inorganic copper(I) halides. Substitution of Cu with Ag leads to (TMS)AgI₂, which has a one-dimensional chain structure made of edge-sharing tetrahedra, with weak light emission properties. Improved stability and highly efficient yellow emission of (TMS)₃Cu₂I₅ make it a candidate for practical applications. This has been demonstrated through utilization of (TMS)₃Cu₂I₅ in white light-emitting diode with a high Color Rendering Index value of 82 and its use as a new luminescent agent for visualization of in-depth latent fingerprint features. This work illuminates a new direction in designing multifunctional nontoxic hybrid metal halides.

Excitation-Dependent Luminescence of 0D ((CH3)4N)2ZrCl6 across the Full Visible Region

Herein, we report a novel hybrid organic-inorganic Zr(IV) metal halide ((CH₃)₄N)₂ZrCl₆, which demonstrates fascinating excitation-dependent luminescence across the full visible region. The single crystal of ((CH₃)₄N)₂ZrCl₆ showed an unexpected high degree of symmetry and formed a unique 0D structure with isolated [ZrCl₆]^2- octahedrons. Amazingly, three different emission groups emerged under changeable excitation light. The first emission group peaked at 462 nm with a ns lifetime and a μs lifetime, which is assigned to free-exciton fluorescence and thermally activated delayed fluorescence (TADF). The second group of emissions featured elaborate multipeak light-emitting components, which is ascribed to the d-d transitions of Zr(IV). The third emission group centered at 660 nm was attributed to the typical self-trapped exciton (STE) emission. To our best knowledge, this work for the first time reports a 0D organic-inorganic metal halide with distinctive excitation-dependent full-visible-spectrum luminescence via four different emission mechanisms.

A Red-Emitting Hybrid Manganese Halide Perovskite C5H5NOMnCl2·H2O Featuring One-Dimensional Octahedron Chains

Herein, we successfully synthesized a new organic-inorganic hybrid manganese halide perovskite C₅H₅NOMnCl₂·H₂O, in which organic molecules, water molecules (through O atoms), and Cl atoms coordinate with Mn atoms to form deformed [MnO₃Cl₃] octahedrons. Then, octahedrons form a chain through edge sharing, resulting in a 1D-chain single crystal structure. The high-quality C₅H₅NOMnCl₂·H₂O single crystal prepared by a simple solvent evaporation method produced bright red emission at 656 nm attributed to the d-d transition of Mn²⁺. Also, it has a photoluminescence quantum yield (PLQY) of 24.2%. Photoluminescence excitation and absorption spectra were both featured with multiple bands and were in good agreement with the Mn²⁺ 3d energy levels. The photoluminescence decay spectrum showed an average lifetime of 0.466 ms, which further proves the d-d transition mechanism. The C₅H₅NOMnCl₂·H₂O single crystal had a direct band gap of 1.43 eV. Moreover, a red light LED with a CCT of 1857 K was obtained based on the C₅H₅NOMnCl₂·H₂O powder, indicating its promising application in red-emitting LED.