Shining Mn~(4+) in 0D Organometallic Fluoride Hosts towards Highly Efficient Photoluminescence

摘要

The design and discovery of Mn4+-activated fluoride phosphors that can secure both high luminescence efficiency and short fluorescence lifetime simultaneously are crucial and urgent for constructing high-quality wide-color gamut (WCG) backlight display applications. Herein, a series of brand-new Mn4+-activated narrow-band red-emitting phosphors with both high external quantum efficiency (EQE, 50) and short fluorescence lifetime (tau = 3.8 ms) are designed by introducing Mn4+ into newfound tetramethylammonium (Me4N)-based organometallic fluoride (Me4N)(2)BF6 (B = Ge, Ti, Zr) hosts. These intriguing properties of Mn4+ arise from the larger steric hindrance of (Me4N)(+) cations and low local structure symmetry in the 0D (Me4N)(2)BF6, as verified by the structural and spectral analyses. (Me4N)(2)GeF6:Mn4+, as a representative, shows a high EQE of approximate to 64.6 and a short lifetime of approximate to 3.78 ms. A prototype projector with superb performance is assembled by employing a remote (Me4N)(2)GeF6:Mn4+-based white light-emitting diode with high luminous efficiency (approximate to 143.09 lm W-1) and WCG (approximate to 112.02 National Television System Committee (NTSC)) to demonstrate their great potentials for backlight applications. The research brings up a promising alternative as the host materials for Mn4+-doped fluoride phosphors and provides a deeper understanding on the correlation between structure and luminescence.