Fig. 1. XRD spectrum (top) of CsPbBr₃ NCs film and standard diffraction pattern (bottom) of CsPbBr₃

Fig. 2. (a) TEM images of CsPbBr₃ NCs; (b) the size distribution of the NCs; (c) SEM images of CsPbBr₃ NCs; (d) CsPbBr₃ NCs films after Al₂O₃ passivation

Fig. 3. (a) UV-Vis absorption spectrum (dotted line) and fluorescence (FL) emission spectrum (solid line) of the CsPbBr₃ NCs; optical photographs of CsPbBr₃ NCs under (b) natural light and (c) UV light

Fig. 4. (a) FL spectra of nanocrystal/metal wire-grid composite films before and after Al₂O₃ passivation; (b) plots of FL intensity of the CsPbBr₃ NCs/metal wire-grid composited film versus time of irradiation by UV light before and after Al₂O₃ passivation; (c) plots of FL intensity of the CsPbBr₃ NCs film versus time of irradiation by UV light before and after Al₂O₃ passivation (Dotted lines are for samples after Al₂O₃ passivation, and solid lines are for samples before the Al₂O₃ passivation)

Fig. 5. (a) Schematic diagram of polarization fluorescence spectroscopy test; (b) FL spectra of CsPbBr₃ NCs/metal wire-grid composited films corresponding to different polarization angles of the exciting light; plots of FL intensities of the CsPbBr₃ NCs/metal wire-grid composited film before (c) and after (d) Al₂O₃ passivation versus the polarization angles of the exciting light