Two-dimensional　(2D)　Sn-based　perovskites　have　emerged　as　a　promising　alternative　to　Pb-based　perovskites　due　to　their　nontoxic　nature.　However,　Sn2+　ions　tend　to　get　oxidized　to　Sn4+　during　the　synthesis　process,　leading　to　crystalline　defects　and　rapid　nonradiative　transitions,　which　limits　their　applications.　In　this　study,　we　present　a　facile　molecular　doping　strategy　for　(C18H35NH3)2SnBr4　perovskite　by　introducing　o-phenylenediamine　(oPD)　in　the　precursor　solution.　The　oPD　serves　a　dual　role:　it　not　only　acts　as　an　electron　donor,　creating　a　reducing　environment　to　suppress　the　oxidation　of　Sn2+,　but　also　functions　as　a　chelating　agent,　forming　stable　compounds　with　Sn2+.　This　approach　results　in　20%　oPD　doped　(C18H35NH3)2SnBr4　perovskite,　which　exhibits　a　high　photoluminescence　quantum　yield　(PLQY)　of　95.3%　and　excellent　stability　against　oxygen.　Furthermore,　UV-pumped　orange　and　white　light-emitting　diodes　(LEDs)　with　a　CIE　coordinate　(0.562,　0.431,　0.327,　and　0.346)　were　produced　using　oPD-doped　2D　tin-based　perovskite　powders,　respectively.　These　findings　suggest　that　the　doping　strategy　has　great　potential　to　enhance　the　stability　of　2D　Sn-based　perovskites　and　facilitate　their　application　in　the　field　of　lighting　devices.　©　2023　American　Chemical　Society.