LAUSR

Summary Although the development of perovskite solar cells (PSCs) surpassed the power conversion efficiencies (PCEs) of well-known thin-film solar cell technologies, approaching its theoretical PCE over 30% is still attractive, albeit challenging. In this Perspective, we examine the current challenges of achieving the record PCE of 25.2% and outline directions toward the theoretical PCE. A survey of the increment of the currently certified PCEs allows a comparison of photovoltaic parameters and suggests that improving the fill factor (FF) value is the determining factor for achieving 25.2%. The parameter limitations for achieving 30% are then clarified on the basis of the performance comparison between PSCs and other photovoltaic technologies. Finally, lessons from the Si and GaAs solar cells are combined to provide strategies for boosting the PCE of PSCs.