초록 |
Photovoltaic applications require manipulation of CsPbI3 perovskite quantum dots (CsPbI3-QDs) surface to replace long-chain ligands such as oleate and oleylammonium with short-chain ligands, in order to improve charge transport. These ligands are sequentially replaced with acetate anions and formamidinium (FA) cations via solid-state ligand exchange. However, FA replacement removes the hydrophobic protective layer, opening the path for moisture penetration and resulting in poor device stability. Herein, we demonstrate that aromatic ring-based hydrophobic phenethylammonium (PEA) cations are incorporated into the CsPbI3-QDs, leading to improved their charge transport and moisture stability. PEA does not change the size, composition, and dimensionality of CsPbI3-QDs and affords high moisture stability under ambient conditions. In addition, PEA-incorporated CsPbI3-QD solar cells show a high device stability and performance with power conversion efficiency of 14.1 %. |