Anisotropic Angstrom-Wide Conductive Channels in Black Phosphorus by Top-down Cu Intercalation

Intercalation is an effective method to improve and modulate properties of two-dimensional materials. Even so, spatially controlled intercalation at atomic scale, which important introduce modulated properties, has not been successful due difficulties in controlling the diffusion intercalants. Here, we show formation angstrom-wide conductive channels (~4.3 A) black phosphorus by Cu intercalation. The structure, resultant microstructural effects, mechanism, local variations electronic were investigated extensively transmission electron microscopy including situ observation, DFT calculation, force microscopy.