Enhanced luminescence stability of high-entropy dual-phase Cs(Pb1/5Mn1/5Ni1/5Zn1/5Cd1/5)Br3/Cs(Pb1/5Mn1/5Ni1/5Zn1/5Cd1/5)2Br5 perovskite nanocrystals coated with SiO2 and EVA

All-inorganic halide perovskite nanocrystals (NCs) have attracted much attention in many fields. However, the poor stability of NCs and the toxicity of Pb have greatly hindered their practical applications. Reducing the proportion of Pb with the concept of high-entropy and coating NCs with an outer layer have been regarded as effective strategies to solve the problems. Herein, We have successfully synthesized the all-inorganic high-entropy dual-phase Cs(Pb 1/5 Mn 1/5 Ni 1/5 Zn 1/5 Cd 1/5 )Br 3 /Cs(Pb 1/5 Mn 1/5 Ni 1/5 Zn 1/5 Cd 1/5 ) 2 Br 5 (Cs‘B’Br 3 /Cs‘B’ 2 Br 5 ) perovskite NCs with good luminescence properties by a high-energy ball milling method; On the basis of which, Cs‘B’Br 3 /Cs‘B 2 ’Br 5 NCs are coated with SiO 2 and EVA resin. Due to the amorphous SiO 2 protection, the Cs‘B’Br 3 /Cs‘B 2 ’Br 5 @SiO 2 NCs maintained 93% of their emission intensity after 90 days compared to their uncoated counterparts. The PL intensity of Cs‘B’Br 3 /Cs‘B 2 ’Br 5 NCs /EVA was significantly enhanced by a factor of 4.7 for compared to the uncoated NCs. In addition, the PL emission intensity of the Cs‘B’Br 3 /Cs‘B 2 ’Br 5 NCs /EVA remained 93.7% after 90 days, and the emission peak intensity remained approximately 63% after 8 h of placement in an enclosed environment at 80% humidity through the dense polymer chains and the hydrophobic nature of the film. Finally, the film could expand its application prospects in the field of flexible device.