Solar energy is considered one of the most important forms of renewable energy. Silicon solar cells are commonly used in the photovoltaic industry, but their higher production costs and complicated fabrication processes make them less affordable. Various other technologies, such as perovskite solar cells and dye-sensitized solar cells, are also emerging. Among these, perovskite solar cells are promising type of solar cells, offering comparable efficiency to that of silicon solar cells, at significantly lower costs. However, one of the drawbacks of perovskite solar cells is their relatively short lifespan, which limits their applications. Researchers are actively working to improve both the lifetime and efficiency of perovskite solar cells. This book begins by covering the basics of solar energy and the principles and different types of solar cells. The focus is then put on perovskite solar cells, how they work, their advantages and challenges, and what sets them apart from other solar cells. Device fabrication techniques and recent advancements in the field are discusses next, finishing up with a look into the future of solar cell technology.