P-doped all-small-molecule organic solar cells with power conversion efficiency of 17.73%

Design of Halogenated Donors for Efficient All-Small-Molecular Organic Solar Cells

“…However, it still falls behind those of polymer solar cells (PSCs), which boost an efficiency exceeding 19%. − The aforementioned phenomena stem from the similar chemical structures of small-molecule donors and acceptors, and the inability to form preaggregation in the solution, , resulting in the unfavorable morphology and lower short-circuit current density ( J sc ) and fill factor (FF). To address above issues, endeavors have been made in molecule design and device engineering techniques including solvent/thermal annealing, mixed solvent approach, additive strategy, etc. − These approaches have been proven to be very favorable in manipulating the phase morphology of all-small-molecule (ASM) systems. Among these, molecule-level designing and optimization play an indispensable and foundational role in manipulating the morphology, contributing significantly to the notable progress achieved in enhancing the efficiencies of ASM-OSCs. − Furthermore, considering the swift advancement of nonfullerene acceptors, it becomes imperative to explore small-molecule donors to address potential shortages in the field.…”