Figure 4: TEM and composition mapping images of a cross-sectioned CZTSSe solar device consisting of Mo/Mo(S,Se)X/CZTSSe/CdS/TCO (i-ZnO/ITO).

The elemental map (in the same scale) revealed aggregates in the CZTSSe layer near the back contact at the interface between the CZTSSe and CdS/TCO layer (the upper image) and near the back contact (the bottom image). Zn(S,Se) aggregates are indicated by dotted circles.