| 초록 |
The use of 2D perovskite materials such as phenethylamine halide (PEAX) on perovskite surface results in superior optoelectronic properties of perovskite solar cells (PSCs). A passivation effect that reduces defects on the 3D perovskite surface has become a mainstream working mechanism for PEAX in most reports. However, we previously revealed that the exact mechanism of PEAX is not passivation but the formation of dipole moments between perovskites and their adjacent layers. Here, we found that stability of PSCs with PEAX is inferior to those without PEAX and suggested the mechanism of how dipole effects of PEAX diminish. Based on the result, we devised a method to retain the dipole effect of PEAX by inserting PMMA (poly(methyl methacrylate)) at the perovskite/PEAX interface. Also, we confirmed that the dipole effect of PEAX on PMMA was further enhanced by heat treatment. This opens up the possibility of applying insulating layers underneath 2D materials to perovskite-based devices. |
