As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such ...As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such as lower photoluminescence quantum yield(PLQY),complex synthetic pathways,uncontrollable emission spectra,and insufficient photostability.In this study,CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra.Then their ensemble spectroscopic properties during nucleation formation,alloying,and ZnS shell growth processes were systematically investigated.PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In,Zn^(2+)doping and ZnS shell growth.In particular,CuInZnS@ZnS QDs possess a significantly long emission lifetime(up to 750 ns),high PLQY(up to 85%),and excellent crystallinity.Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model.By controlling the stoichiometric ratio of Cu/In,two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects.Therefore,this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.展开更多
CdS and CdS/ZnS quantum dots were synthesized by the microemulsion method in sulfosuccinic acid bis(2-ethylhexyl)ester sodium salt(AOT) surfactant reverse micelles containing water.The products were characterized by U...CdS and CdS/ZnS quantum dots were synthesized by the microemulsion method in sulfosuccinic acid bis(2-ethylhexyl)ester sodium salt(AOT) surfactant reverse micelles containing water.The products were characterized by UV-Vis spectrometer,transmission electronmicroscopy(TEM),energy dispersive X-ray spectroscope(EDX)and photoluminescence(PL) spectroscope.The diameter of CdS/ZnS nanoparticle was obvious larger than that of CdS nanoparticle.The diameter of the nanoparticle was estimated,which was confirmed by the images of TEM.The existence of core-shell structure was established by the result of energy dispersive X-ray analysis.PL studies of the samples showed that the luminescence from CdS was enhanced by the ZnS shell.A possible reason was that the ZnS shell reduced the number of defects on the surface of CdS quantum dots,which were assumed to act as centers for radiation-free recombination.展开更多
基金Fund Project for Transformation of Scientific and Technological Achievements of Jiangsu Province of China(BA2023020)。
文摘As an essential candidate for environment-friendly luminescent quantum dots(QDs),CuInS-based QDs have attracted more attention in recent years.However,several drawbacks still hamper their industrial applications,such as lower photoluminescence quantum yield(PLQY),complex synthetic pathways,uncontrollable emission spectra,and insufficient photostability.In this study,CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra.Then their ensemble spectroscopic properties during nucleation formation,alloying,and ZnS shell growth processes were systematically investigated.PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In,Zn^(2+)doping and ZnS shell growth.In particular,CuInZnS@ZnS QDs possess a significantly long emission lifetime(up to 750 ns),high PLQY(up to 85%),and excellent crystallinity.Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model.By controlling the stoichiometric ratio of Cu/In,two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects.Therefore,this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.
文摘CdS and CdS/ZnS quantum dots were synthesized by the microemulsion method in sulfosuccinic acid bis(2-ethylhexyl)ester sodium salt(AOT) surfactant reverse micelles containing water.The products were characterized by UV-Vis spectrometer,transmission electronmicroscopy(TEM),energy dispersive X-ray spectroscope(EDX)and photoluminescence(PL) spectroscope.The diameter of CdS/ZnS nanoparticle was obvious larger than that of CdS nanoparticle.The diameter of the nanoparticle was estimated,which was confirmed by the images of TEM.The existence of core-shell structure was established by the result of energy dispersive X-ray analysis.PL studies of the samples showed that the luminescence from CdS was enhanced by the ZnS shell.A possible reason was that the ZnS shell reduced the number of defects on the surface of CdS quantum dots,which were assumed to act as centers for radiation-free recombination.
基金Supported by National Natural Science Foundation of China(11547018)Research Foundation of Education Bureau of Hubei Province(Q20142706)+1 种基金Natural Science Foundation of Hubei Engineering University(z2013028)Natural Science Foundation of Hubei Province(2014CFB579)~~
