| 초록 |
Here we study perovskite solar cells, which are devoid of a discrete n-type electron collection layer. We employ ethoxylated polyethylenimine (PEIE) polymeric interlayer to modify the interface between the perovskite absorber layer and the metallic transparent fluorine-doped SnO2 (FTO) electrode. Surprisingly, the PEIE interlayer obviates the requirement for the conventional dense-TiO2 (d-TiO2) compact interlayer (or organic fullerene layer), usually required to selectively extract electrons from the perovskite film. The self-organized PEIE interlayer produced a strong induced dipole moment at the perovskite-FTO interface, which results in electron accumulation in the perovskite film at this interface. The resultant n-type contact region, progressing to an intrinsic region within the bulk of the perovskite layer, favorably enables selective electron extraction at the FTO electrode. |
