Lead halide perovskite quantum dots(QDs)suffer from frequent batch-to-batch inconsistencies and poor reproducibility,resulting in serious non-radiative defect-assisted recombination and Auger recombination.To overcome...Lead halide perovskite quantum dots(QDs)suffer from frequent batch-to-batch inconsistencies and poor reproducibility,resulting in serious non-radiative defect-assisted recombination and Auger recombination.To overcome these challenges,in this study,CsPbBr3 QDs were prepared by designing a novel cesium precursor recipe that involved a combination of dual-functional acetate(AcO-)and 2-hexyldecanoic acid(2-HA)as short--branched-chain ligand:first,AcO aided in significantly improving the complete conversion degree of cesium salt,enhancing the purity of the cesium precursor from 70.26%to 98.59%with a low relative standard deviation of size distribution and photoluminescence quantum yield(9.02 and 0.82%,respectively)by decreasing the formation of by-products during the reaction,which leads to enhanced homogeneity and reproducibility,especially at room-temperature.Second,AcO can act as a surface ligand to passivate the dangling surface bonds.Furthermore,compared to oleic acid,2-HA exhibited a stronger binding affinity toward the QDs,further passivated the surface defects,and effectively suppressed biexciton Auger recombination,thereby improving the spontaneous emission rate of the QDs.Consequently,the QDs prepared using this new recipe exhibited a uniform size distribution,a green emission peak at 512 nm,a high photoluminescence quantum yield of 99%with excellent stability,and a narrow emission linewidth of 22 nm.In particular,the optimized QDs exhibited enhanced amplified spontaneous-2 emission(ASE)performance,while the ASE threshold of treated QDs reduced by 70%from 1.8μJ·cm to 0.54μJ·cm-2.展开更多
Recently organic-inorganic perovskite has been established as a promising platform for achieving room temperature exciton-polaritons,attributable to its superior optical coherence and robust exciton binding energies.H...Recently organic-inorganic perovskite has been established as a promising platform for achieving room temperature exciton-polaritons,attributable to its superior optical coherence and robust exciton binding energies.However,when interfaced with metallic surfaces,the rapid degradation and quenching effect in perovskite have presented significant challenges,which critically hinders the exploration of light-matter interactions within metallic plasmonic structures.In this study,we report a quasi-two-dimensional lead halide perovskite that demonstrates a pronounced strong coupling phenomenon within an array of aluminum nanocones.The investigated quasi-two-dimensional perovskite structure exhibits high photoluminescence quantum efficiency and improved stability against metallic-induced degradation.Interestingly,the periodical arraying in honeycomb formation of plasmonic structure has advantages in angle-dependent dispersions and the loss neutralizing effectively.Besides,the plasmonic cone lattice characterized by its collective surface lattice resonance,features an exceptionally small mode volume and high quality,enhancing its interaction with the perovskite.A significant Rabi splitting of 243 meV is observed at an incident angle of 30°.The dynamics of the Rabi oscillation is revealed by transient absorption spectra and theoretically analyzed by cavity quantum electrodynamics.This advancement in polariton research paves the way for novel applications,including quantum sources,enhanced photon-electron conversion efficiencies,and low-threshold lasing.展开更多
Quantum dot light-emitting diodes(QLEDs)have attracted considerable attention in displays owing to their high color purity,wide gamut,narrow emission band,and solution-processed characteristics.However,a major problem...Quantum dot light-emitting diodes(QLEDs)have attracted considerable attention in displays owing to their high color purity,wide gamut,narrow emission band,and solution-processed characteristics.However,a major problem of the unbalanced carrier(electrons and holes)injection in QLEDs deteriorates their performance.Here,we balanced the charge injection in QLEDs by optimizing the carrier transport layers.Different organic hole transport layers(HTLs)with a suitable thickness were employed to match the electron transport layer(ETL)of ZnO.Mg^(2+) was doped into the ZnO(MZO)ETL to decrease the electron mobility and match the hole mobility of the HTL.Consequently,the QLEDs exhibited an excellent external quantum efficiency(EQE)of 21.10%at a luminance of 4661 cd m^(-2).In the luminance range of 100–30,000 cd m^(-2),EQE roll-off was considerably low,and more than 80%of the initial EQE value could be maintained,indicating less Auger recombination because of the balanced carrier injection.This work reveals that compared with energy level matching,the charge transfer capability of the transport layers is more instrumental in the charge balance regulation of QLED devices.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52302171)Shandong Provincial Natural Science Foundation,China(ZR2023QF005)+2 种基金Heilongjiang Provincial Natural Science Foundation of China(LH2023F026,LH2020A007,and LH2020F027)New Era Longjiang Excellent Doctoral Discovery Project(LJYXL2022-003),Teaching Reform Research Project of Harbin Engineering University(79005023/013)Fundamental Research Funds for the Central Universities(3072024XX2606,3072022TS2613,79000012/012).
文摘Lead halide perovskite quantum dots(QDs)suffer from frequent batch-to-batch inconsistencies and poor reproducibility,resulting in serious non-radiative defect-assisted recombination and Auger recombination.To overcome these challenges,in this study,CsPbBr3 QDs were prepared by designing a novel cesium precursor recipe that involved a combination of dual-functional acetate(AcO-)and 2-hexyldecanoic acid(2-HA)as short--branched-chain ligand:first,AcO aided in significantly improving the complete conversion degree of cesium salt,enhancing the purity of the cesium precursor from 70.26%to 98.59%with a low relative standard deviation of size distribution and photoluminescence quantum yield(9.02 and 0.82%,respectively)by decreasing the formation of by-products during the reaction,which leads to enhanced homogeneity and reproducibility,especially at room-temperature.Second,AcO can act as a surface ligand to passivate the dangling surface bonds.Furthermore,compared to oleic acid,2-HA exhibited a stronger binding affinity toward the QDs,further passivated the surface defects,and effectively suppressed biexciton Auger recombination,thereby improving the spontaneous emission rate of the QDs.Consequently,the QDs prepared using this new recipe exhibited a uniform size distribution,a green emission peak at 512 nm,a high photoluminescence quantum yield of 99%with excellent stability,and a narrow emission linewidth of 22 nm.In particular,the optimized QDs exhibited enhanced amplified spontaneous-2 emission(ASE)performance,while the ASE threshold of treated QDs reduced by 70%from 1.8μJ·cm to 0.54μJ·cm-2.
基金National Natural Science Foundation of China(61905051,61905049,12174321)Natural Science Foundation of Heilongjiang Province(LH2020F027,LH2020A007).
文摘Recently organic-inorganic perovskite has been established as a promising platform for achieving room temperature exciton-polaritons,attributable to its superior optical coherence and robust exciton binding energies.However,when interfaced with metallic surfaces,the rapid degradation and quenching effect in perovskite have presented significant challenges,which critically hinders the exploration of light-matter interactions within metallic plasmonic structures.In this study,we report a quasi-two-dimensional lead halide perovskite that demonstrates a pronounced strong coupling phenomenon within an array of aluminum nanocones.The investigated quasi-two-dimensional perovskite structure exhibits high photoluminescence quantum efficiency and improved stability against metallic-induced degradation.Interestingly,the periodical arraying in honeycomb formation of plasmonic structure has advantages in angle-dependent dispersions and the loss neutralizing effectively.Besides,the plasmonic cone lattice characterized by its collective surface lattice resonance,features an exceptionally small mode volume and high quality,enhancing its interaction with the perovskite.A significant Rabi splitting of 243 meV is observed at an incident angle of 30°.The dynamics of the Rabi oscillation is revealed by transient absorption spectra and theoretically analyzed by cavity quantum electrodynamics.This advancement in polariton research paves the way for novel applications,including quantum sources,enhanced photon-electron conversion efficiencies,and low-threshold lasing.
基金supported by the National Natural Science Foundation of China(51774034,51961135107 and 51772026)the National Key Research&Development Program of China(2017YFE0119700)。
文摘Quantum dot light-emitting diodes(QLEDs)have attracted considerable attention in displays owing to their high color purity,wide gamut,narrow emission band,and solution-processed characteristics.However,a major problem of the unbalanced carrier(electrons and holes)injection in QLEDs deteriorates their performance.Here,we balanced the charge injection in QLEDs by optimizing the carrier transport layers.Different organic hole transport layers(HTLs)with a suitable thickness were employed to match the electron transport layer(ETL)of ZnO.Mg^(2+) was doped into the ZnO(MZO)ETL to decrease the electron mobility and match the hole mobility of the HTL.Consequently,the QLEDs exhibited an excellent external quantum efficiency(EQE)of 21.10%at a luminance of 4661 cd m^(-2).In the luminance range of 100–30,000 cd m^(-2),EQE roll-off was considerably low,and more than 80%of the initial EQE value could be maintained,indicating less Auger recombination because of the balanced carrier injection.This work reveals that compared with energy level matching,the charge transfer capability of the transport layers is more instrumental in the charge balance regulation of QLED devices.
