Photoinduced interfacial charge transfer plays a critical role in energy conversion involving van der Waals(vdW)heterostructures constructed of inorganic nanostructures and organic materials.However,the effect of mole...Photoinduced interfacial charge transfer plays a critical role in energy conversion involving van der Waals(vdW)heterostructures constructed of inorganic nanostructures and organic materials.However,the effect of molecular stacking configurations on charge transfer dynamics is less understood.In this study,we demonstrated the tunability of interfacial charge separation in a type-Ⅱ heterojunction between monolayer(ML)WS_(2) and an organic semiconducting molecule[2-(3″′,4′-dimethyl-[2,2′:5′,2′:5″,2″′-quaterthiophen]-5-yl)ethan-1-ammonium halide(4Tm)]by rational design of relative stacking configurations.The assembly between ML-WS_(2) and the 4Tm molecule forms a face-to-face stacking when 4Tm molecules are in a selfaggregation state.In contrast,a face-to-edge stacking is observed when 4Tm molecule is incorporated into a 2D organic-inorganic hybrid perovskite lattice.The face-to-face stacking was proved to be more favorable for hole transfer from WS_(2) to 4Tm and led to interlayer excitons(IEs)emission.Transient absorption measurements show that the hole transfer occurs on a time scale of 150 fs.On the other hand,the face-to-edge stacking resulted in much slower hole transfer without formation of IEs.This inefficient hole transfer occurs on a similar time scale as A exciton recombination in WS_(2),leading to the formation of negative trions.These investigations offer important fundamental insights into the charge transfer processes at organic−inorganic interfaces.展开更多
基金primarily supported by the US Department of Energy,Office of Basic Energy Sciences under award number DE-SC0022082support from National Science Foundation under award number 2143568-DMR.
文摘Photoinduced interfacial charge transfer plays a critical role in energy conversion involving van der Waals(vdW)heterostructures constructed of inorganic nanostructures and organic materials.However,the effect of molecular stacking configurations on charge transfer dynamics is less understood.In this study,we demonstrated the tunability of interfacial charge separation in a type-Ⅱ heterojunction between monolayer(ML)WS_(2) and an organic semiconducting molecule[2-(3″′,4′-dimethyl-[2,2′:5′,2′:5″,2″′-quaterthiophen]-5-yl)ethan-1-ammonium halide(4Tm)]by rational design of relative stacking configurations.The assembly between ML-WS_(2) and the 4Tm molecule forms a face-to-face stacking when 4Tm molecules are in a selfaggregation state.In contrast,a face-to-edge stacking is observed when 4Tm molecule is incorporated into a 2D organic-inorganic hybrid perovskite lattice.The face-to-face stacking was proved to be more favorable for hole transfer from WS_(2) to 4Tm and led to interlayer excitons(IEs)emission.Transient absorption measurements show that the hole transfer occurs on a time scale of 150 fs.On the other hand,the face-to-edge stacking resulted in much slower hole transfer without formation of IEs.This inefficient hole transfer occurs on a similar time scale as A exciton recombination in WS_(2),leading to the formation of negative trions.These investigations offer important fundamental insights into the charge transfer processes at organic−inorganic interfaces.
