Heavy Mn-doped CsPbBr₃nanocrystals synthesized by high energy ball milling with high stability

CsPbX₃(X = Cl, Br, I) semiconductor nanocrystals (NCs) have excellent optical and photoelectric properties, and are potential core materials for various photoelectric devices. However, the toxicity of Pb and instability have been the key limitations to application of NCs. Herein, using MnBr₂and MnBr₂·4H₂O as manganese sources, heavy Mn-doped CsPbBr₃(Mn:CsPbBr₃) NCs are synthesized by high-energy ball grinding, which avoids high temperature, a large number of polar solvents and atmosphere protection required in traditional liquid phase methods. However, when MnBr₂·4H₂O is used as the raw material, infinite solid solution doping can be achieved, and the synthesized Mn:CsPbBr₃NCs show smaller particle size, stronger PL intensity and stability. The reason is that presence of crystal water plays a similar role to wet milling in the ball milling process, and can promote the passivation effect of oleylamine (OAm) on nanocrystal defects and the connection between them. In addition, a simple, easy-operating and beneficial to commercial production method for the preparation of Mn:CsPbBr₃NCs/EVA flexible films is proposed, which can effectively improve the stability of Mn:CsPbBr₃NCs. This study is expected to provide an effective way for the synthesis and stability improvement of CsPbX₃NCs doped with different ions.