Solidification of solvent additive for stable binary polymer solar cells with~19%efficiency

Polymer solar cells(PSCs)have garnered considerable attention due to their numerous benefits,such as solution-processability,and potential applications in flexible and semitransparent devices.With the development of photovoltaic materials and device structures,power conversion efficiencies(PCEs)of PSCs have exceeded 19%to date[1,2].Moreover,an ideal morphology for efficient and stable PSCs is extremely essential[3,4].