The solvent additive strategy has been widely utilized to boost the power conversion efficiency (PCE) of organic solar cells(OSCs).However,the residual solvent additive in the active layer tends to induce a gradual morphology degradation and further influences the long-term stability of OSCs.Here,a solid additive,1,4-diiodobenzene (DIB),was introduced to fabricate efficient OSCs.We found that the treatment of DIB can lead to optimized morphology to form a bicontinuous network with intensified intermolecular packing in the donor and acceptor phases.Notably,DIB can be easily removed from the active layer via a simple alcohol washing process and no further post-thermal annealing is needed,which is desirable for large-scale manufacturing of OSCs.As a result,high efficiencies of 17.47% for PM6:Y6 and 18.13% (certified as 17.7%) for PM6:BTP-eC9 binary OSCs are achieved,which are among the highest efficiencies reported for binary OSCs thus far.Moreover,OSCs fabricated with DIB also exhibit superior stability compared with the as-cast and traditional solvent additive processed devices.Additionally,DIB was successfully applied in different active layers,manifesting its general applicability.This work provides a feasible approach to enhance both the efficiency and stability of OSCs.