Environmental-Friendly Cs<sub>3</sub>Mn<sub><i>x</i></sub>Zn<sub>(1–<i>x</i>)</sub>Br<sub>5</sub>@PS Films Used for Wide Color Gamut Backlight Displays
Wenya Chen, Qingyun He, Ziyao He, Qin Wang, Jing Ding, Qiao Huang, Xiaojuan Liang, Zhaoping Chen, Weidong Xiang
Abstract
In recent years, all-inorganic metal lead halide cesium perovskites (CsPbX3, X = Cl, Br, and I) have shown excellent luminescence performance in the field of wide color gamut backlight displays. However, Pb2+ in CsPbX3 easily leaks because of the unstable structure of CsPbX3, which seriously threatens human health. However, Mn-based metal halides (MHs) have unique environmentally friendly characteristics. In this work, Zn2+-doped Cs3MnBr5 MHs were successfully prepared, which exhibited highly efficient green emissions at 520–522 nm. Moreover, Cs3MnxZn(1–x)Br5 shows excellent stability at room temperature (25 °C) compared with Cs3MnBr5. More excitingly, when Cs3MnxZn(1–x)Br5 was encapsulated in a polystyrene (PS) polymer, Cs3MnxZn(1–x)Br5@PS showed better water, acid, daylight, and blue light stabilities. In addition, the backlight display device was designed based on different green–red ratios and thicknesses of Cs3MnxZn(1–x)Br5@K2SiF6:Mn4+@PS light conversion films, and the color gamut was over 109% of the NTSC 1953 standard, which is better than that of the reported WLED devices based on Mn-based MHs thus far. This work undoubtedly shows that Mn-based MHs have great application potential in wide color gamut backlight displays and provide a practicable route to fabricate nontoxic, low-cost, and high-performance liquid crystal displays.