초록 |
We investigated the effect of the alkyl chain length of alkylamine ligands (AALs), known as linker molecules to organometallic perovskite crystallites, on the preferential alignment of the CsFAMA crystal domains by GIWAXS measurements. With different incident angles, 2D diffraction signals to the penetration depth of samples were obtained. At the film surface, we observed higher alignment of (100) domains to the surface normal direction (vertically aligned, ? = 0˚) with reducing a 45˚ tilted (100) (? = ± 45˚) domain as the longer AALs was added in the film. The effective depth of film with vertically aligned (100) domains increased with longer chain length of AALs as well. And an additional isotropic (100) domain with consuming a 45˚ tilted (100) domain appeared over the whole volume of film, especially in the case of longer AALs used. These results imply that the change of the (100) perovskite crystals alignment was dominant at the surface region of the film. |