초록 |
To improve stability against moisture, silanization (covering of a surface with silane ligand) strategy is utilized for passivating the surface of quantum dots. We introduced the silane ligand with CH3-end capping, thereby obtaining silica core/shell quantum dots with hydrophobic surface and high dispersibility. Also, the hydrophobic shell protects the core, thereby suppressing the release of heavy metal (Pb) of perovskite. In terms of energy level, it has a deeper HOMO to prevent hole injection. Based on this advantage, MAPbBr3 silica core/shell quantum dots were thinly stacked on bulk MAPbI3 (photosensitive layer) surface. In this way, more hydrophobic surface was observed for the silica core/shell quantum dots applied photosensitive layer. Also, it was confirmed the perovskite grains were largely grown, and smoother topography was observed. By these morphological effects, the stable characteristics of the photodiode was proved with highly improved detectivity. |