Heavy Mn-doped CsPbBr 3 nanocrystals synthesized by high energy ball milling with high stability.

CsPbX 3 (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 MnBr 2 and MnBr 2 ·4H 2 O as manganese sources, heavy Mn-doped CsPbBr 3 (Mn:CsPbBr 3 ) 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 MnBr 2 ·4H 2 O is used as the raw material, infinite solid solution doping can be achieved, and the synthesized Mn:CsPbBr 3 NCs 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:CsPbBr 3 NCs/EVA flexible films is proposed, which can effectively improve the stability of Mn:CsPbBr 3 NCs. This study is expected to provide an effective way for the synthesis and stability improvement of CsPbX 3 NCs doped with different ions.