Fabrication of Hybrid Low-Dimensional Perovskite Solar Cells by Combing Scalable Doctor Blade Coating and Methylamine Post Treatment

Three-dimensional (3D) metal-halide perovskites have been paid much attention for use in solar cells due to the high absorption coefficient, great ambipolar charge mobility, long carrier diffusion length, and low exciton binding energy. However, the poor stability of 3D perovskite from the hydrophilic nature limits the practical application. In this regard, the hybrid low-dimensional perovskites are developed by combing the doctor blade coating and methylamine post-treatment process. A series of different hybrid low-dimensional perovskites are facilely made by the addition of phenethylammonium iodide (PEAI) in the doctor blade coating solution of MAPbI₃ perovskite based on the hot-casting approach. The result shows that the addition of PEAI can form a low-dimensional perovskite layer on top of the 3D MAPbI₃ perovskite film right after the doctor blade coating, which improves the perovskite stability but lowers the device performance due to the large bandgap and poor charge transportation. To find a compromise between the device stability and performance, the methylamine post-treatment process is employed on such a hybrid low-dimensional perovskite. The SEM, XRD, Raman microscopy, Kelvin probe force microscopy (KPFM), and UV-Vis are carried out to understand the morphology, crystallization, contact potential difference and optical property of the hybrid low-dimensional perovskites before and after the methylamine post treatment. More details related to the perovskite device stability and performance, affected by the amount of added PEAI and methylamine post treatment, will be mentioned in the presentation.