A near unity pyridinium manganese(II)-based luminescent halide for multifunctional applications

Zero-dimensional organic-inorganic hybrid metal halides (OIMHs) have exhibited considerable potential for applications in the backlight display, lighting, and anti-counterfeiting areas. Developing new OIMHs with high photoluminescence quantum yield (PLQY) and environmental stability holds significant importance. Herein, a novel zero-dimensional pyridinium manganese-based OIMH, (C 14 H 16 N) 2 MnCl 4 (C 14 H 16 N = 1-benzyl-3,5-dimethylpyridinium), was synthesized via a solvent evaporation method. This crystal displays a distinct green emission centered at 524 nm, which is attributed to the d-d transition of Mn 2 + ions under multiple excitation wavelengths. At the optimal excitation wavelength of 307 nm, (C 14 H 16 N) 2 MnCl 4 achieves a PLQY of 97.6 % and remarkable environmental stability, along with a lifetime of 2.557 ms. When combined with K 2 SiF 6 :Mn 4+ and (Sr, Ca)AlSiN 3 :Eu 2+ , two white light LEDs were fabricated for backlight display and illumination applications, respectively. The first white LED produces efficient white light emission with a correlated color temperature (CCT) of 5388 K and a wide color gamut of 99.9 % NTSC. The second LED shows a CCT of 4666 K, CIE coordinates of (0.3501, 0.3245), and a color rendering index of 87.1, meeting the lighting requirements. Finally, a large area of highly transparent flexible luminescent fiber film was produced using an electrospinning technique, demonstrating considerable potential for applications in information encryption and warnings under dark conditions. This new crystal shows a good prospect in multifunctional luminescence applications.