Fig. 2From: Imaging of polymer:fullerene bulk-heterojunctions in a scanning electron microscope: methodology aspects and nanomorphology by correlative SEM and STEMa Cross-section scheme of the model sample with alternating PTB7 and PC71BM layers stacked on a Si substrate. b Top-view SE-SEM image of the prepared wedge-shaped specimen and c offset-thickness determination by EFTEMBack to article page