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.