Figure 1. Planar heterojunction PSCs using a nanocarbon layer to suppress layer-to-layer ions/molecules diffusion and facilitate electron charge carrier diffusion.

(a) SEM cross-section image of a NiMgLiO/Perovskite/N-doped graphene fullerene derivative phenyl-C61-butyric acid methyl ester (G-PCBM)/CQDs/Ag device, in which G-PCBM is graphene doped PCBM. (b) Schematic drawing of the diffusion processes within the nanocarbon-based EEL. (c) Energy band structure of the planar heterojunction cell.