Lead sulfide quantum dots(PbS QDs)are promising candidates for high-performance solar cells due to their tunable bandgaps and low-cost solution processing.However,low carrier mobility and numerous surface defects rest...Lead sulfide quantum dots(PbS QDs)are promising candidates for high-performance solar cells due to their tunable bandgaps and low-cost solution processing.However,low carrier mobility and numerous surface defects restrict the performance of the fabricated solar cells.Herein,we report the synthesis of novel PbS-perovskite core-shell QDs to solve the low carrier mobility problem of PbS QDs via a facile hot injection method.CsPbI_(2)Br shell enabled strain-free epitaxial growth on the surface of PbS QDs because of 98%lattice match.Our results demonstrate a significant improvement in the photoluminescence and stability of the synthesized PbS-CsPbI_(2)Br QDs upon shell formation,attributed to the effective suppression of surface defects by the epitaxial shell of CsPbI_(2)Br.As a result,the obtained solar cell based on PbS-CsPbI_(2)Br core-shell QD exhibits a power conversion efficiency(PCE)of 8.43%,two times higher than that of pristine PbS QDs.Overall,the construction of PbS-CsPbI_(2)Br core-shell structures represent a promising strategy for advancing the performance of PbS QDs-based optoelectronic devices.展开更多
Crystalline Ge is a highly active anode material for Li storage but inactive for Na storage because of high diffusion barrier. By in-situ Raman spectrum, we explore that the Na could reversibly ailoy/dealloy with the ...Crystalline Ge is a highly active anode material for Li storage but inactive for Na storage because of high diffusion barrier. By in-situ Raman spectrum, we explore that the Na could reversibly ailoy/dealloy with the amorphous Ge, but does not with the crystalline Ge. Herein, the amorphous Ge is fabricated by an acid-etching Zintl phase Mg2Ge route at room temperature, which shows a mesoporous architecture with a Brunauer-Emmett-Teller (BET) surface area of 29.9 m^2·g^-1 and a Barrett-Joyner-Halenda (BJH) average pore diameter of 7.6 nm. This mesoporous architecture would enhance the Na-ion/electron diffusion rate and buffer the volume expansion. As a result, the as-prepared amorphous Ge shows superior Na-ion storage performance including high reversible capacity over 550 mA·h·g^-1 at 0.2 C after 50 cycles, good rate capability with a capacity of 273 mA·h·g^-1 maintained at 5.0 C, and long-term cycling stability with capacities of 450 mA·h·g^-1 at 0.4 C after 200 cycles. For the K-ion storage, the amorphous Ge is also more active than the crystalline counter and maintains a capacity of 210 mA·h·g^-1 after 100 cycles at 0.2 C.展开更多
基金the National Postdoctoral Program for Innovative Talents (No.BX201600140)China Postdoctoral Science Foundation funded project (No.2016M600484)+2 种基金the Fundamental Research Funds for the Central Universities (No.WK2060190078)the National Natural Science Fund of China (No.21701163) and Anhui Provincial Natural Science Foundation (No.1808085QB25).
基金support from the National Natural Science Foundation of China(Nos.22325505,52073271,and 22305236)the USTC Research Funds of the Double First-Class Initiative(No.YD2060002034)+1 种基金the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP018)the China Postdoctoral Science Foundation(Nos.2023M733375 and 2023T160619).
文摘Lead sulfide quantum dots(PbS QDs)are promising candidates for high-performance solar cells due to their tunable bandgaps and low-cost solution processing.However,low carrier mobility and numerous surface defects restrict the performance of the fabricated solar cells.Herein,we report the synthesis of novel PbS-perovskite core-shell QDs to solve the low carrier mobility problem of PbS QDs via a facile hot injection method.CsPbI_(2)Br shell enabled strain-free epitaxial growth on the surface of PbS QDs because of 98%lattice match.Our results demonstrate a significant improvement in the photoluminescence and stability of the synthesized PbS-CsPbI_(2)Br QDs upon shell formation,attributed to the effective suppression of surface defects by the epitaxial shell of CsPbI_(2)Br.As a result,the obtained solar cell based on PbS-CsPbI_(2)Br core-shell QD exhibits a power conversion efficiency(PCE)of 8.43%,two times higher than that of pristine PbS QDs.Overall,the construction of PbS-CsPbI_(2)Br core-shell structures represent a promising strategy for advancing the performance of PbS QDs-based optoelectronic devices.
基金supported by the National Natural Science Foundation of China (Nos.21701163, 21671181, and 21831006)Anhui Provincial Natural Science Foundation (No.1808085QB25).
文摘Crystalline Ge is a highly active anode material for Li storage but inactive for Na storage because of high diffusion barrier. By in-situ Raman spectrum, we explore that the Na could reversibly ailoy/dealloy with the amorphous Ge, but does not with the crystalline Ge. Herein, the amorphous Ge is fabricated by an acid-etching Zintl phase Mg2Ge route at room temperature, which shows a mesoporous architecture with a Brunauer-Emmett-Teller (BET) surface area of 29.9 m^2·g^-1 and a Barrett-Joyner-Halenda (BJH) average pore diameter of 7.6 nm. This mesoporous architecture would enhance the Na-ion/electron diffusion rate and buffer the volume expansion. As a result, the as-prepared amorphous Ge shows superior Na-ion storage performance including high reversible capacity over 550 mA·h·g^-1 at 0.2 C after 50 cycles, good rate capability with a capacity of 273 mA·h·g^-1 maintained at 5.0 C, and long-term cycling stability with capacities of 450 mA·h·g^-1 at 0.4 C after 200 cycles. For the K-ion storage, the amorphous Ge is also more active than the crystalline counter and maintains a capacity of 210 mA·h·g^-1 after 100 cycles at 0.2 C.
