The use of perovskites as light harvesters and emitters has revolutionized the field of photovoltaics. The unique combination of broad and high absorption coefficients along with the large carrier diffusion lengths give perovskites an edge over other emerging technologies. This Special Collection of ChemPlusChem, organized with Guest Editors Shahzada Ahmad, Giulia Grancini, and Mohammad K. Nazeeruddin, covers a broad range of topics, including materials, fabrication techniques, mechanistic studies, simulations, and machine learning.