Perovskite　/　silicon　heterojunction　tandem　solar　cell　has　been　regarded　as　a　promising　strategy　to　break　the　inherent　Shockley-Queisser　limit　imposed　on　single-junction　solar　cells.　However,the　existence　of　defects　within　the　multi-crystalline　perovskite　active　layer　would　form　additional　recombination　centers　for　photo-generated　carriers,and　bring　about　unfavorable　losses　to　the　performance　of　solar　cells.　Therefore,it　is　both　necessary　and　significant　to　explore　effective　passivation　approaches.　In　this　work,we　adopt　1,4-diaminobutane　dihydrochloride　by　mixing　it　into　the　perovskite　precursor　and　found　this　could　optimize　the　performance　of　monolithic　perovskite　/　silicon　tandem　solar　cells.　Ultimately,the　synergistic　effects　contributed　by　the　component　chloride　ion　and　diaminobutane　of　1,4-diaminobutane　dihydrochloride　improve　both　the　open-circuit　voltage　and　fill　factor,and　this　help　us　to　achieve　a　certified　PCE　of　28.　77%　by　NREL.　©　2024　Cailiao　Daobaoshe/　Materials　Review.　All　rights　reserved.