The　loss　of　open-circuit　voltage　is　a　major　obstacle　for　approaching　the　theoretical　value　of　the　power　conversion　efficiency　in　hybrid　perovskite　solar　cells.　In　this　study,　a　feasible　and　effective　strategy　for　modifying　the　interface　between　the　perovskite　and　the　mesoporous　TiO2　layer　is　proposed　and　implemented　for　the　first　time　using　2-methylimidazole　as　a　coating　layer.　As　a　result,　the　open-circuit　voltage　in　the　perovskite　solar　cells　is　significantly　improved　by　80　mV.　The　electronic　impedance　spectroscopy　and　photoluminescence　spectroscopy　results　demonstrate　that　the　modification　of　2-methylimidazole　as　an　interfacial　insulating　layer　suppresses　the　electron　transfer　back　from　the　anode　electrode　to　the　perovskite　active　layer,　thereby　inhibiting　the　recombination　of　the　carriers　at　the　interfaces,　which　results　in　an　enhancement　of　the　open-circuit　voltage　in　the　device.　The　cell　modified　with　2-methylimidazole　shows　increases　in　the　open-circuit　voltage　from　1.05　to　1.13　V　and　in　the　power　conversion　efficiency　from　17.48%　to　19.45%.　The　optimal　device　with　an　area　of　1　cm2　also　exhibits　an　impressive　efficiency　of　16.38%.　©　2020　Elsevier　B.V.