We investigated the optical properties of hybrid exciton–plasmon coupling ensembles composed of ZnSe/ZnS quantum dots and Ag nanoparticles in aqueous solution. We modulated their average interval by changing the rati...We investigated the optical properties of hybrid exciton–plasmon coupling ensembles composed of ZnSe/ZnS quantum dots and Ag nanoparticles in aqueous solution. We modulated their average interval by changing the ratio of quantum dots and Ag nanoparticles. The transition from dramatic PL enhancement to PL quenching state was experimentally observed, according to the continuous decrease of the PL lifetime. The PL enhancement rate exceeded 10, with the Purcell factor of 3.5. Meanwhile, the proportion of fast decay increased from 0.3 to 0.6, corresponding to the proportion of slow decay decreased from 0.7 to 0.4. Our experiment is important for the hybrid exciton–plasmon coupling system to be practicable in optoelectronic application.展开更多
CuZnSe/ZnS core/shell quantum dots exhibiting yellow fluorescent emission were synthesized in aqueous phase via a one-potmicrowave irradiation approach, where glutathione （GSH） as stabilizer and selenium dioxide （S...CuZnSe/ZnS core/shell quantum dots exhibiting yellow fluorescent emission were synthesized in aqueous phase via a one-potmicrowave irradiation approach, where glutathione （GSH） as stabilizer and selenium dioxide （SeO2） containing Cu as seleniumsource, respectively. The QDs obtained at the optimal conditions without any post-treatment present high crystallinity, which wasconfirmed by transmission electron microscopy （TEM） and high resolution transmission electron microscopy （HRTEM）. Thecore/shell structure was confirmed by X-ray photoelectron spectra （XPS） and Powder X-ray diffraction （XRD）. The binding ofGSH on the surface of QDs through thiol ligands was proved by the characterization of Fourier Transform Infrared Spectroscopy（FTIR）, suggesting the biocompatibility of the obtained QDs.展开更多
Quasi-type II heterostructured nanocrystals(NCs)have been of particular interest due to their great potential for controlling the interplay of charge carriers.However,the lack of material choices for quasi-type II NCs...Quasi-type II heterostructured nanocrystals(NCs)have been of particular interest due to their great potential for controlling the interplay of charge carriers.However,the lack of material choices for quasi-type II NCs restricts the accessible emission wavelength from red to near-infrared(NIR),which hinders their use in light-emitting applications that demand a wide range of visible colors.Herein,we demonstrate a new class of quasi-type II nanoemitters formulated in ZnSe/ZnSe_(1-X)Te_(X)/ZnSe seed/spherical quantum well/shell heterostructures(SQWs)whose emission wavelength ranges from blue to orange.In a given geometry,ZnSe_(1-X)Te_(X) emissive layers grown between the ZnSe seed and the shell layer are strained to fit into the surrounding media,and thus,the lattice mismatch between ZnSe_(1-X)Te_(X) and ZnSe is effectively alleviated.In addition,composition of the ZnSe_(1-X)Te_(X) emissive layer and the dimension of the ZnSe shell layer are engineered to tailor the distribution and energy of electron and hole wave functions.Benefitting from the capabilities to tune the charge carriers on demand and to form defectfree heterojunctions,ZnSe/ZnSe_(1-X)Te_(X)/ZnSe/ZnS NCs show near-unity photoluminescence quantum yield(PLQY>90%)in a broad range of emission wavelengths(peak PL from 450nm to 600 nm).Finally,we exemplify dichromatic white NC-based light-emitting diodes(NC-LEDs)employing the mixed layer of blue-and yellow-emitting ZnSe/ZnSe_(1-X)TeX/ZnSe/ZnS SQW NCs.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2018YFA0306304)the National Natural Science Foundation of China(Grant No.11674069)
文摘We investigated the optical properties of hybrid exciton–plasmon coupling ensembles composed of ZnSe/ZnS quantum dots and Ag nanoparticles in aqueous solution. We modulated their average interval by changing the ratio of quantum dots and Ag nanoparticles. The transition from dramatic PL enhancement to PL quenching state was experimentally observed, according to the continuous decrease of the PL lifetime. The PL enhancement rate exceeded 10, with the Purcell factor of 3.5. Meanwhile, the proportion of fast decay increased from 0.3 to 0.6, corresponding to the proportion of slow decay decreased from 0.7 to 0.4. Our experiment is important for the hybrid exciton–plasmon coupling system to be practicable in optoelectronic application.
文摘CuZnSe/ZnS core/shell quantum dots exhibiting yellow fluorescent emission were synthesized in aqueous phase via a one-potmicrowave irradiation approach, where glutathione （GSH） as stabilizer and selenium dioxide （SeO2） containing Cu as seleniumsource, respectively. The QDs obtained at the optimal conditions without any post-treatment present high crystallinity, which wasconfirmed by transmission electron microscopy （TEM） and high resolution transmission electron microscopy （HRTEM）. Thecore/shell structure was confirmed by X-ray photoelectron spectra （XPS） and Powder X-ray diffraction （XRD）. The binding ofGSH on the surface of QDs through thiol ligands was proved by the characterization of Fourier Transform Infrared Spectroscopy（FTIR）, suggesting the biocompatibility of the obtained QDs.
基金the National Research Foundation of Korea(NRF)grant funded by the Ministry of Science,ICT and Future Planning(No.2020M3H4A1A01086888,No.2020M3D1A2101319,No.2020R1A2C2011478,and No.2019M3D1A1078299)the Ministry of Trade,Industry&Energy(MOTIE,Korea)(No.20010737)the Electronics and Telecommunications Research Institute(ETRI)grant funded by the Korean Government(No.20ZB1200,Development of ICT Materials,Components and Equipment Technologies).G.N.and L.A.P.are thankful for the financial support from the Sao Paulo Research Foundation(FAPESP)under the grant No.2018/15574-6.
文摘Quasi-type II heterostructured nanocrystals(NCs)have been of particular interest due to their great potential for controlling the interplay of charge carriers.However,the lack of material choices for quasi-type II NCs restricts the accessible emission wavelength from red to near-infrared(NIR),which hinders their use in light-emitting applications that demand a wide range of visible colors.Herein,we demonstrate a new class of quasi-type II nanoemitters formulated in ZnSe/ZnSe_(1-X)Te_(X)/ZnSe seed/spherical quantum well/shell heterostructures(SQWs)whose emission wavelength ranges from blue to orange.In a given geometry,ZnSe_(1-X)Te_(X) emissive layers grown between the ZnSe seed and the shell layer are strained to fit into the surrounding media,and thus,the lattice mismatch between ZnSe_(1-X)Te_(X) and ZnSe is effectively alleviated.In addition,composition of the ZnSe_(1-X)Te_(X) emissive layer and the dimension of the ZnSe shell layer are engineered to tailor the distribution and energy of electron and hole wave functions.Benefitting from the capabilities to tune the charge carriers on demand and to form defectfree heterojunctions,ZnSe/ZnSe_(1-X)Te_(X)/ZnSe/ZnS NCs show near-unity photoluminescence quantum yield(PLQY>90%)in a broad range of emission wavelengths(peak PL from 450nm to 600 nm).Finally,we exemplify dichromatic white NC-based light-emitting diodes(NC-LEDs)employing the mixed layer of blue-and yellow-emitting ZnSe/ZnSe_(1-X)TeX/ZnSe/ZnS SQW NCs.
