Environmental-Friendly Cs3MnxZn(1-x)Br5@PS Films Used for Wide Color Gamut Backlight Displays

In recent years, all-inorganic metal lead halide cesium perovskites (CsPbX3, X = Cl, Br, and I) have shown excellentluminescence performance in the field of wide color gamut backlightdisplays. However, Pb2+in CsPbX3easily leaks because of the unstablestructure of CsPbX3, which seriously threatens human health.However, Mn-based metal halides (MHs) have unique environ-mentally friendly characteristics. In this work, Zn2+-doped Cs3MnBr5MHs were successfully prepared, which exhibited highly efficient greenemissions at 520-522 nm. Moreover, Cs3MnxZn(1-x)Br5showsexcellent stability at room temperature (25 degrees C) compared withCs3MnBr5. More excitingly, when Cs3MnxZn(1-x)Br5was encapsulatedin a polystyrene (PS) polymer, Cs3MnxZn(1-x)Br5@PS showed betterwater, acid, daylight, and blue light stabilities. In addition, the backlightdisplay device was designed based on different green-red ratios and thicknesses of Cs3MnxZn(1-x)Br5@K2SiF6:Mn4+@PS lightconversionfilms, and the color gamut was over 109% of the NTSC 1953 standard, which is better than that of the reported WLEDdevices 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.

Automated summary

In recent years, all-inorganic metal lead halide cesium perovskites have shown excellent luminescence performance in wide color gamut backlight displays. However, the leakage of Pb2+ due to the unstable structure of cesium perovskites poses a serious threat to human health. This study successfully prepared Zn-doped Cs3MnBr5 metal halides, which demonstrated highly efficient green emission and excellent stability. Encapsulating the metal halides in a polymer further improved their water, acid, daylight, and blue light stabilities. The designed backlight display device based on these metal halides achieved a color gamut that surpassed the NTSC 1953 standard, showing great potential for non-toxic, low-cost, and high-performance liquid crystal displays.