Coexisting CsPbCl3:CsPbI3 perovskite nanocrystal glasses with high luminescence and stability

Many previous studies have reported that because of the large difference between the ionic radii of Cl and I, halogen exchange is difficult to occur between CsPbCl3 and CsPbI3 perovskite nanocrystals, and the interaction between CsPbCl3 and CsPbI3 NCs will lead to their dissolution. In this work, two kinds of nanocrystals, CsPbCl3 and CsPbI3, were successfully crystallized simultaneously in glass by an in-situ growth method for the first time. Because of the effective reabsorption of photons, the CsPbCl3:CsPbI3 nanocrystals displayed higher fluorescence emission intensity and higher photoluminescence quantum yield than those of CsPbI3 nanocrystals. In addition, CsPbCl3:CsPbI3 nanocrystal glasses showed excellent water resistance and thermal stability, which benefited from the effective protection of the glass matrix. In particular, the fluorescence intensity of the nanocomposites remained above 95% after immersion in water for 60 days. Light-emitting devices were prepared by combining a near-infrared-emitting CsPbCl3:CsPbI3 nanocrystal glass and 400 nm LED chip, which were applied to indoor plant growth.