Abstract
In the modern era, energy demand rises dramatically accompanied by the rapid growth of our population, causing urgent energy shortages and environmental issues around the globe. People turned their attention to solar energy for an eco-friendly and economic solution, in which, perovskite solar cells emerged and had caught a great deal of attention in the past decades for their promising and commercial development potential. To fully release their capability for a high-performance device, defect mechanisms which are one of the main factors inhibiting the efficiency and stability, as well as passivation strategies must be thoroughly studied. In this review, the concept and formation mechanism of the defects are summarized, the corresponding defect characterization techniques regarding their working principles and downsides were also compared. Furthermore, substantial passivation strategies were discussed. Although perovskite solar cells still have a long way to go, facing difficulties in a lot of other aspects, we believe that the research we are doing now is of great significance in making perovskite into a real application.