Fig. 3.

Compositional and crystallographic analysis of nanowire heterojunctions. a HAADF-STEM image, and the corresponding STEM-EDS elemental maps, of a heterojunction CdSe/Cu₂Se NW. The white box indicates the region that was exposed to e-beam irradiation. Scale bar is 200 nm. b HRTEM image of the CdSe/Cu₂Se interface found in the heterojunction’s region marked with a dashed yellow box in a, with the corresponding FFT showing the epitaxial relationship between CdSe and Cu₂Se (c). d Mean dilation map calculated from the GPA analysis of the HRTEM image shown in b. Scale bar in b is 5 nm