Low photolumines-cence(PL)quantum yield of molybdenum disulfide(MoS_(2))quan-tum dots(QDs)has lim-ited practical applica-tion as potential fluores-cent materials.Here,we report the intercalation of aluminum ion(Al^(3+...Low photolumines-cence(PL)quantum yield of molybdenum disulfide(MoS_(2))quan-tum dots(QDs)has lim-ited practical applica-tion as potential fluores-cent materials.Here,we report the intercalation of aluminum ion(Al^(3+))to enhance the PL of MoS_(2)QDs and the un-derlying mechanism.With detailed characterization and exciton dynamics study,we suggest that additional surface states including new emission centers have been effectively introduced to MoS_(2)QDs by the Al^(3+)intercalation.The synergy of new radiative pathway for exciton re-combination and the passivation of non-radiative surface traps is responsible for the en-hanced fluorescence of MoS_(2)QDs.Our findings demonstrate an efficient strategy to improve the optical properties of MoS_(2)QDs and are important for understanding the regulation effect of surface states on the emission of two dimensional sulfide QDs.展开更多
Defect-mediated processes in two-dimensional transition metal dichalcogenides have a significant influence on their carrier dynamics and transport properties,however,the detailed mechanisms remain poorly understood.He...Defect-mediated processes in two-dimensional transition metal dichalcogenides have a significant influence on their carrier dynamics and transport properties,however,the detailed mechanisms remain poorly understood.Here,we present a comprehensive ultrafast study on defect-mediated carrier dynamics in ion exchange prepared few-layer MoS2 by femtosecond time-resolved Vis-NIR-MIR spectroscopy.The broadband photobleaching feature observed in the near-infrared transient spectrum discloses that the mid-gap defect states are widely distributed in few-layer MoS2 nanosheets.The processes of fast trapping of carriers by defect states and the following nonradiative recombination of trapped carriers are clearly revealed,demonstrating the mid-gap defect states play a significant role in the photoinduced carrier dynamics.The positive to negative crossover of the signal observed in the mid-infrared transient spectrum further uncovers some occupied shallow defect states distributed at less than0.24 e V below the conduction band minimum.These defect states can act as effective carrier trap centers to assist the nonradiative recombination of photo-induced carriers in few-layer MoS2 on the picosecond time scale.展开更多
Strong coupling between plasmons and multiple different exciton states(MESs)enables the creation of multiple hybrid polariton states under ambient conditions.These hybrid states possess unique optical properties diffe...Strong coupling between plasmons and multiple different exciton states(MESs)enables the creation of multiple hybrid polariton states under ambient conditions.These hybrid states possess unique optical properties different from those of their separate identities,making them ideal candidates for exploiting room-temperature multimode hybridization and multiqubit operation.In this study,we revealed the static spectral response properties of plasmon-MES strong coupling via a fully quantum mechanics approach.These theoretical predictions were experimentally demonstrated in plasmonic nanocavities containing two and three different exciton species.Additionally,the dynamical absorption processes of such strong coupling systems were investigated,and results indicated that the damping of the hybrid polariton states induced by the strong coupling could be markedly modulated by the acoustic oscillations from the plasmonic nanocavities.Our findings contribute a theoretical approach for accurately describing the plasmon-MES interactions and a platform for developing the high-speed active plasmonic devices based on multiqubit strong coupling.展开更多
基金supported by the National Natural Sci-ence Foundation of China(No.12004101,No.61905066,No.22103024,No.61805070,and No.22105063)the Nat-ural Science Foundation of Henan Province(No.202300410065)the Open Project of the State Key Laboratory of Crop Stress Adaptation and Im-provement.
文摘Low photolumines-cence(PL)quantum yield of molybdenum disulfide(MoS_(2))quan-tum dots(QDs)has lim-ited practical applica-tion as potential fluores-cent materials.Here,we report the intercalation of aluminum ion(Al^(3+))to enhance the PL of MoS_(2)QDs and the un-derlying mechanism.With detailed characterization and exciton dynamics study,we suggest that additional surface states including new emission centers have been effectively introduced to MoS_(2)QDs by the Al^(3+)intercalation.The synergy of new radiative pathway for exciton re-combination and the passivation of non-radiative surface traps is responsible for the en-hanced fluorescence of MoS_(2)QDs.Our findings demonstrate an efficient strategy to improve the optical properties of MoS_(2)QDs and are important for understanding the regulation effect of surface states on the emission of two dimensional sulfide QDs.
基金supported by the National Key Research and Development Program of China(No.2018YFA0208700)the National Natural Science Foundation of China(No.21603270 and No.21773302)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB30000000)。
文摘Defect-mediated processes in two-dimensional transition metal dichalcogenides have a significant influence on their carrier dynamics and transport properties,however,the detailed mechanisms remain poorly understood.Here,we present a comprehensive ultrafast study on defect-mediated carrier dynamics in ion exchange prepared few-layer MoS2 by femtosecond time-resolved Vis-NIR-MIR spectroscopy.The broadband photobleaching feature observed in the near-infrared transient spectrum discloses that the mid-gap defect states are widely distributed in few-layer MoS2 nanosheets.The processes of fast trapping of carriers by defect states and the following nonradiative recombination of trapped carriers are clearly revealed,demonstrating the mid-gap defect states play a significant role in the photoinduced carrier dynamics.The positive to negative crossover of the signal observed in the mid-infrared transient spectrum further uncovers some occupied shallow defect states distributed at less than0.24 e V below the conduction band minimum.These defect states can act as effective carrier trap centers to assist the nonradiative recombination of photo-induced carriers in few-layer MoS2 on the picosecond time scale.
基金supported by the National Natural Science Foundation of China(Grant Nos.11874438,22105063,61905066,61805070,1200410122103024)+1 种基金Natural Science Foundation of Guangdong(Grant Nos.2021A1515010050,and 2018A030313722)Guangdong Polytechnic Normal University Talent Introduction Project Foundation of China(Grant No.XY2019022)。
文摘Strong coupling between plasmons and multiple different exciton states(MESs)enables the creation of multiple hybrid polariton states under ambient conditions.These hybrid states possess unique optical properties different from those of their separate identities,making them ideal candidates for exploiting room-temperature multimode hybridization and multiqubit operation.In this study,we revealed the static spectral response properties of plasmon-MES strong coupling via a fully quantum mechanics approach.These theoretical predictions were experimentally demonstrated in plasmonic nanocavities containing two and three different exciton species.Additionally,the dynamical absorption processes of such strong coupling systems were investigated,and results indicated that the damping of the hybrid polariton states induced by the strong coupling could be markedly modulated by the acoustic oscillations from the plasmonic nanocavities.Our findings contribute a theoretical approach for accurately describing the plasmon-MES interactions and a platform for developing the high-speed active plasmonic devices based on multiqubit strong coupling.
