Shining Mn<sup>4+</sup> in 0D Organometallic Fluoride Hosts towards Highly Efficient Photoluminescence
Hong Ming, Yifei Zhao, Yayun Zhou, Мaxim S. Моlokeev, Yuanjing Wang, Shuai Zhang, Enhai Song, Shi Ye, Zhiguo Xia, Qinyuan Zhang
Abstract
Abstract The design and discovery of Mn 4+ ‐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 Mn 4+ ‐activated narrow‐band red‐emitting phosphors with both high external quantum efficiency (EQE, >50%) and short fluorescence lifetime (τ ≤ 3.8 ms) are designed by introducing Mn 4+ into newfound tetramethylammonium (Me 4 N)‐based organometallic fluoride (Me 4 N) 2 B F 6 ( B = Ge, Ti, Zr) hosts. These intriguing properties of Mn 4+ arise from the larger steric hindrance of (Me 4 N) + cations and low local structure symmetry in the 0D (Me 4 N) 2 B F 6 , as verified by the structural and spectral analyses. (Me 4 N) 2 GeF 6 :Mn 4+ , as a representative, shows a high EQE of ≈64.6% and a short lifetime of ≈3.78 ms. A prototype projector with superb performance is assembled by employing a remote (Me 4 N) 2 GeF 6 :Mn 4+ ‐based white light‐emitting diode with high luminous efficiency (≈143.09 lm W −1 ) and WCG (≈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 Mn 4+ ‐doped fluoride phosphors and provides a deeper understanding on the correlation between structure and luminescence.