Over　the　past　few　years,　the　photoelectric　conversion　efficiency　(PCE)　of　organic-inorganic　hybrid　perovskite　solar　cells　(PSCs)　has　continuously　been　promoted,　and　a　PCE　of　27.3%　has　been　achieved.　However,　the　inherent　lability　has　hindered　the　commercialization　process　of　PSCs.　Under　unfavorable　conditions,　CsFAMA-based　perovskite　can　emerge　the　ionic　migration　and　volatilization,　generating　defects　which　adversely　affect　the　photovoltaic　performance　and　stability　of　the　devices.　Herein,　the　p-fluorophenylacetyl　chloride　molecules　(4-FBCl)　with　multifunctional　groups　(-C=O　and　[sbnd]F)　were　first　introduced　to　inhibit　the　migration　and　volatilization　of　cations　in　the　perovskite　lattice,　effectively　passivating　the　defects　by　coordinating　with　Pb2+　and　forming　hydrogen　bond　interactions　with　N[sbnd]H　in　FA+.　Concurrently,　the　functional　groups　present　within　the　4-FBCl　molecules　established　chemical　interactions　with　PbI2　and　FAI　in　perovskite　precursor　solution.　It　demonstrated　that　this　process　decelerated　the　reaction　between　PbI2　and　FAI　to　reduce　the　nucleation　sites　during　the　annealing　process,　which　could　delay　perovskite　crystallization　and　enhance　the　preferred　orientation　of　the　perovskite　(110)　crystal　plane,　thus　significantly　improving　the　crystallization　quality　of　the　perovskite.　Moreover,　the　immobilization　of　cations　and　inhibition　of　FA+　volatilization　had　a　significant　effect　on　stabilizing　the　crystal　structure　of　perovskite,　thus　suppressing　the　precipitation　of　PbI2.　As　a　result,　a　PCE　of　the　4-FBCl-modified　device　exhibited　a　superior　elevation　(from　23.06%　to　24.85%).　Furthermore,　it　also　had　an　excellently　environmental　stability　under　the　high-temperature　and　high-humidity　conditions,　maintaining　84%　of　its　initial　efficiency　for　1600　h　at　25　°C,　20–25%　relative　humidity　without　encapsulation.　©　2025　Elsevier　B.V.