Aqueous synthesis of stable Zn alloyed manganese halides for efficient backlit display

Metal halide perovskite has been widely researched in the field of wide color gamut backlight due to its excellent luminescence properties. However, the toxicity of lead and thermal stability issue greatly hindered its practical application. In this regard, environmentally friendly manganese halide perovskites has intrigued great attention. Herein, facile yet robust preparation of highly emissive all-inorganic manganese halides is presented via a one-step pure aqueous solution-based method without using corrosive acid solution. The introduction of Zn2+ cation-alloying enables the weakly luminescent Cs3MnCl5 to exhibit exceptionally efficient green emission at 521 nm. The alloyed Cs3MnxZn(1-x)Cl5 exhibits superior optical properties as well as improved thermal stability. In particular, alloyed Cs3MnxZn(1-x)Cl5 still retained 74% of the initial fluorescence intensity when the heating temperature was raised up to 225 °C. Furthermore, within the protective encapsulation of polydimethylsiloxane (PDMS) matrix, the prepared Cs3MnxZn(1-x)Cl5@PDMS films demonstrates excellent air, water and blue-light stability, which can be readily applied as light conversion films in backlit display. The as-prepared Cs3MnxZn(1-x)Cl5@K2SiF6: Mn4+@PDMS films displayed excellent quality and the color gamut was over 113% of the NTSC 1953 standard. This work provides a simple and effective pure aqueous-based strategy for the development of environment-friendly perovskite materials for the application of wide color gamut backlit display.