Fig. 2: Structural and physicochemical characterizations of the CsPbI3@COF-Cl system.

a, b TEM images showing CsPbI3 QDs (black dots) confined within the COF-Cl matrix. c HRTEM image with lattice spacing of confined CsPbI3 QD in CsPbI3@COF-Cl system. Inset: Magnified view of the CsPbI3 QD showing atomic arrangement. d Fast-Fourier transform pattern corresponding to the CsPbI3 QDs, confirming their high crystallinity. e HAADF-STEM image of the CsPbI3@COF-Cl system. Inset: Size distribution histogram of the confined CsPbI3 QDs. f EDX elemental mapping showing the spatial distribution of Cl, Cs, Pb, and I within the same region. g Contact angle measurements on a pressed tablet of the CsPbI3@COF-Cl system. h PXRD pattern of the CsPbI3@COF-Cl system. i N2 sorption isotherms at 77 K and corresponding Brunauer-Emmett-Teller (BET) surface area plots for pristine COF-Cl and the CsPbI3@COF-Cl system. Source data are provided as a Source Data file.