Extended Data Fig. 1: Vertical structure of carbon nitride and silicon.

a, Cross-sectional TEM images of the edge parts of sample (1) (left), sample (4) (middle), and sample (7) (right). The sampling spots are marked with red stars in insets (sampling position 10 in Fig. 1e). b-e, Cross-sectional TEM images of the central parts of sample (1) (b), sample (6) (c), sample (7) (d), and sample (8) (e) grown on the p-Si wafer.