Recent progress in solution-processed flexible organic photovoltaics

The certified power conversion efficiency(PCE)of organic photovoltaics(OPV)fabricated in laboratories has improved dramatically to over 19%owing to the rapid development of narrow-bandgap small-molecule acceptors and wide bandgap polymer donor materials.The next pivotal question is how to translate small-area laboratory devices into large-scale commercial applications.This requires the OPV to be solution-processed and flexible to satisfy the requirements of high-throughput and large-scale production such as roll-to-roll printing.This review summarizes and analyzes recent progress in solution-processed flexible OPV.After a detailed discussion from the perspective of the behavior of the narrow bandgap small-molecule acceptor and wide bandgap polymer donor active layer in solution-processed flexible devices,the existing challenges and future directions are discussed.