Fig. 2: Structure and composition of ultrathin PBOC layers.

a−f STEM-EDS elemental-mapping images and the corresponding element atomic concentrations. g Bi 4f and Pb 4f spectra of ultrathin PBOC layer. h−k Atom-resolved inversed FFT HAADF- and BF- STEM images, with the labelled zone axis (O and Cl atoms are omitted for the sake of clarity in Fig. k). l Le Bail fitting results against PXRD pattern.