Two　new　hole　selective　materials　(HSMs)　based　on　dangling　methylsulfanyl　groups　connected　to　the　C-9　position　of　the　fluorene　core　are　synthesized　and　applied　in　perovskite　solar　cells.　Being　structurally　similar　to　a　half　of　Spiro-OMeTAD　molecule,　these　HSMs　(referred　as　FS　and　DFS)　share　similar　redox　potentials　but　are　endowed　with　slightly　higher　hole　mobility,　due　to　the　planarity　and　large　extension　of　their　structure.　Competitive　power　conversion　efficiency　(up　to　18.6%)　is　achieved　by　using　the　new　HSMs　in　suitable　perovskite　solar　cells.　Time-resolved　photoluminescence　decay　measurements　and　electrochemical　impedance　spectroscopy　show　more　efficient　charge　extraction　at　the　HSM/perovskite　interface　with　respect　to　Spiro-OMeTAD,　which　is　reflected　in　higher　photocurrents　exhibited　by　DFS/FS-integrated　perovskite　solar　cells.　Density　functional　theory　simulations　reveal　that　the　interactions　of　methylammonium　with　methylsulfanyl　groups　in　DFS/FS　strengthen　their　electrostatic　attraction　with　the　perovskite　surface,　providing　an　additional　path　for　hole　extraction　compared　to　the　sole　presence　of　methoxy　groups　in　Spiro-OMeTAD.　Importantly,　the　low-cost　synthesis　of　FS　makes　it　significantly　attractive　for　the　future　commercialization　of　perovskite　solar　cells.　©　2019　WILEY-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim