Green massive mechanical synthesis of highly efficient Zn-Doped Cs3Cu2I5 for LED and X-ray imaging applications

As a new generation of environmentally friendly halide materials, Cs 3 Cu 2 I 5 shows up the promising application in scintillation, LED, and photoelectric detection fields. However, liquid phase methods cannot produce Cs 3 Cu 2 I 5 on a large scale, and the preparation process is accompanied by serious pollution. Although the ball milling method can solve the problems caused by the liquid phase synthesis method, the Cs 3 Cu 2 I 5 obtained has many surface defects and low luminescence efficiency. In this work, a strategy of doping-assisted ball-milling synthesis using ZnI 2 is proposed. Similar to the chemical preparation of Cs 3 Cu 2 I 5 , the iodine-rich environment during the modified ball milling process can also play a role in repairing surface defects. And it has been demonstrated through experiments and first principles calculations that the distortion of [Cu 2 I 5 ] 3- under ground/excited state can be adjusted through doping Zn into the Cu1 site, the formation barrier of self-trapped excitons is reduced, and the luminous efficiency of Cs 3 Cu 2 I 5 is significantly improved. Subsequently, using the simple hot-pressing method, the representative Cs 3 Cu 2 I 5 :1.0Zn sample was combined with commercially available polypropylene to fabricate Cs 3 Cu 2 I 5 :1.0Zn@PP film. Finally, the potential applications of the newly-developed film in portable and customizable WLED and scintillation fields were explored.