Abstract:
All-solid-state perovskite solar cells become a promising alternative for the new age thin film solar cells. From 2009, the power conversion efficiency (PCE) has rapidly increased from 3.8% to 20.1%. Although the high efficiency of these solar cells is being intensively investigated by many researchers, degradation of perovskite has been a big problem in all-solid-state perovskite solar cells. In order to elongate the life time of the solar cells in outdoor working condition, the factors of degradation should be the first to be known. In this study, several factors that may affect the degradation of Methyl ammonium lead iodide perovskite (CH3NH3PbI3), which is commonly used as light absorption material in such photoelectric devices, were investigated. Meanwhile, it was discovered that a certain amount of PbI2 species usually existed in the CH3NH3PbI3 film fabricated by two-step method and it may led to improved carrier behavior. The effect on stability due to the presence of PbI2 was also studied. These kinds of studies help us to find out the main factors causing the degradation of CH3NH3PbI3.