Perovskite solar cells (PSCs) have received significant attention in academia and industry due to their low cost and high-power conversion efficiency (PCE). Single- and multijunction PSCs have obtained promising certified PCEs, which suggests that PSCs are a very promising next-generation photovoltaic technology. In addition to the perovskite absorber layer, other functional layers, including electron transport layer (ETL), hole transport layer (HTL), and electrode layer (EL), have also made huge contributions to enhancing device performance. This book focuses on the development, advancement, and application of these functional layers in various PSCs. This volume: Introduces ETL, HTL, and EL in efficient and stable PSCs. Covers material properties. Discusses a wide variety of PSCs including single-crystal PSCs, flexible PSCs, perovskite tandem solar cells, lead-free PSCs, inorganic PSCs, fully printable mesoscopic PSCs, electron/hole-transport-layer-free PSCs, semitransparent PSCs for building-integrated photovoltaics (BIPV), tandem solar cells, perovskite indoor photovoltaics, and inverted PSCs. Details potential for commercial application. This book is aimed at researchers, advanced students, and industry professionals in materials, energy, and related areas of engineering who are interested in development and commercialization of photovoltaic technologies.