Unraveling the Ultrafast Self-assembly and Photoluminescence in Zero-Dimensional Mn2+-Based Halides with Narrow-Band Green Emissions

摘要

The discovery of narrow-band luminescent materials remains an immense challenge to optimize the performance of white light-emitting diodes (LEDs). So far, the zero-dimensional (0D) Mn2+-based halides with near-unity narrow-band emissions have emerged as a class of promising phosphors in solid-state displays, but the related large-scale synthesis strategies have not been proposed and evaluated. Herein, we report an in situ synthetic process of 0D Mn2+-based halides and utilize (C20H20P)(2)MnBr4 as a case to investigate the photoluminescence characteristics and the structural essence of ultrafast self-assembly. The bright green emission peak at 523 nm with a full width at half maximum of 48 nm for (C20H20P)(2)MnBr4 is attributed to the d-d transition (T-4(1)-(6)A(1)) of tetrahedrally coordinated [MnBr4](2-) centers, and the fabricated white LED device shows a wide color gamut of 103.7% National Television System Committee (NTSC) standard. Remarkably, the experimental and theoretical results indicate that there are hydrogen bonding of C-H center dot center dot center dot Br and weak van der Waals interactions between [C20H20P]+ and [MnBr4](2-), resulting in the root for the realization of ultrafast self-assembly in 0D Mn2+-based halides. This work reveals a feasible and general synthesis method for preparing 0D Mn2+-based halides, thereby providing a possibility for their industrial application in solid-state displays.

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