| 초록 |
Nowadays, researches for renewable and sustainable energy including solar energy are actively carried out due to various environmental problems. Among them, Perovskite solar cells (PSCs) are getting a lot of attention because of its great photoelectric properties and low process cost. Formamidinium lead iodide (FAPbI3) is the most efficient perovskite material for PSCs to date. But, it has two types of phase, cubic perovskite phase (alpha phase) which has high photoelectric performance and hexagonal non-perovskite phase (delta phase) which has low photoelectric performance. Unfortunately, delta phase is more favorable than alpha phase in room temperature (RT). Therefore we should keep FAPbI3 to alpha phase in RT for highly efficient solar cells. We can do it by not only substituting some ions of FAPbI3 but also protecting from moisture. It is because smaller ions can reduce strain which causes the phase transition of FAPbI3 and moisture accelerates the phase transition by reducing activation energy. |
