LAUSR

Summary Currently, most cathode interlayer (CIL) materials for organic solar cells (OSCs) cannot be processed by printing techniques, which severely limits their use in practical productions. Herein, we report a naphthalene diimide (NDI)-based small-molecular compound (N,N-dimethylamino)propyl naphthalene diimide (NDI-N) as printable CIL for OSCs. NDI-N exhibits a unique advantage that combines the merits of high crystallinity and good film-forming property in one material, endowing the semiconductor with excellent electron-transport properties and good processability. By using the NDI-N as CIL, a high power-conversion efficiency (PCE) of 13.9% was achieved in a PBDB-T-2F:IT-4F-based OSC device. More importantly, a large-area OSC device of 1 cm2 was fabricated by using the blade-coated NDI-N CIL and an outstanding PCE of 13.2% was achieved, which represents the highest efficiency of large-area OSCs. The results in this work may pave the way for low-cost and mass production of OSCs.