For efficient colloidal quantum dot(CQD)solar cells(CQD-SCs),thiol-passivated p-type CQDs are generally used as a hole-transporting material(HTM);however,there are issues with the control of optoelectrical properties,...For efficient colloidal quantum dot(CQD)solar cells(CQD-SCs),thiol-passivated p-type CQDs are generally used as a hole-transporting material(HTM);however,there are issues with the control of optoelectrical properties,low thiol passivation rate,and poor morphology with a power conversion efficiency(PCE)of approximately 11%.Although polymeric HTMs have been introduced to address these issues,maximizing efficiency and achieving green-solvent processability and thermal stability for commercialization is necessary.Here,we synthesize a novel benzodifuran(BDF)-based HTM(asy-ranPBTBDF)showing an electron-deficient state,low steric hindrance,and low planarity compared to those of a typical benzodithiophene(BDT)-based HTM(asy-ranPBTBDT).BDF properties lead to deep high occupied molecular orbital(HOMO)levels,closeπ-πstacking,excellent solubility,and amorphous properties related to efficiency,green-solvent processability,and thermal stability.With these benefits,the asy-ranPBTBDF-based CQD-SC showed enhanced open-circuit voltage(Voc)(0.65 V)and PCE(13.29%)compared to those of the asy-ranPBTBDT-based device(0.63 V and 12.22%)in toxic processes with chlorobenzene.The asy-ranPBTBDF-based CQD-SC showed a PCE of 12.51%in a green-solvent process with 2-methylanisole and improved thermal stability at 80℃(83.8%retaining after 24 h)owing to less lateral crystallization than the asy-ranPBTBDT-based device(60.8%retaining after 24 h).展开更多
It is of great significance to study the brain structure and function in deep-tissue for neuroscience research and bio-medical applications because of the urgent demand for precise theranostics.Three-photon fluorescen...It is of great significance to study the brain structure and function in deep-tissue for neuroscience research and bio-medical applications because of the urgent demand for precise theranostics.Three-photon fluorescence microscopic(3PFM)bioimaging excited by the light in near-infrared IIb(NIR-IIb,1,500–1,700 nm)spectral region is one of the most promising imaging techniques with the advantages of high spatial resolution,large imaging depth,and reduced scattering.Herein,a type of NIR-IIb light excitable deep-red emissive semiconducting polymer dots(P-dots)with bright 3PF and large three-photon absorption cross-section(σ3)at 1,550 nm was prepared.Then the P-dots were functionalized with polystyrene polymer polystyrene graft ethylene oxide functionalized with carboxyl groups(PS-PEG-COOH)and modified with NH2-poly(ethylene glycol)(PEG)to synthesis photochemically stable and biocompatible P-dots nanoparticles(NPs).Further the P-dots NPs were utilized for in vivo 3PFM bioimaging of cerebral vasculature with and without the brain skull under 1,550 nm femtosecond(fs)laser excitation.In vivo 3PFM bioimaging of the mice cerebral vasculature at various vertical depths was obtained.Moreover,a vivid three-dimensional structure of the mice vascular architecture beneath the skull was reconstructed.At the depth of 350μm beneath the brain skull,3.8μm blood vessels could still be clearly recognized.NIR-IIb excitable P-dots assisted 3PFM bioimaging has great potential in accurate deep tissue bioimaging.展开更多
Owing to the outstanding characteristics of tailorable electronic and optical properties,semiconducting polymers have attracted considerable attention in recent years.Among them,organic polymer dots process large brea...Owing to the outstanding characteristics of tailorable electronic and optical properties,semiconducting polymers have attracted considerable attention in recent years.Among them,organic polymer dots process large breadth of potential synthetic diversity are the representative of photocatalysts for hydrogen production,which presents both an opportunity and a challenge.In this mini-review,first,the organic polymer photocatalysts were introduced.Then,recent reports on polymer dots which showed a superior photocatalytic activity and a robust stability under visible-light irradiation,for hydrogen production were summarized.Finally,challenges and outlook on using organic polymer dots-based photocatalysts from hydrogen production were discussed.展开更多
基金supported by National Research Foundation of Korea(NRF)grant funded by Ministry of Science and ICT(MSIT)(2021R1A2C3004420,2021M3H4A1A02055684,and 2020R1C1C1012256)the DGIST R&D Program of the Ministry of Science and ICT(21-CoE-ET-01)Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2021R1A6A3A14038599).
文摘For efficient colloidal quantum dot(CQD)solar cells(CQD-SCs),thiol-passivated p-type CQDs are generally used as a hole-transporting material(HTM);however,there are issues with the control of optoelectrical properties,low thiol passivation rate,and poor morphology with a power conversion efficiency(PCE)of approximately 11%.Although polymeric HTMs have been introduced to address these issues,maximizing efficiency and achieving green-solvent processability and thermal stability for commercialization is necessary.Here,we synthesize a novel benzodifuran(BDF)-based HTM(asy-ranPBTBDF)showing an electron-deficient state,low steric hindrance,and low planarity compared to those of a typical benzodithiophene(BDT)-based HTM(asy-ranPBTBDT).BDF properties lead to deep high occupied molecular orbital(HOMO)levels,closeπ-πstacking,excellent solubility,and amorphous properties related to efficiency,green-solvent processability,and thermal stability.With these benefits,the asy-ranPBTBDF-based CQD-SC showed enhanced open-circuit voltage(Voc)(0.65 V)and PCE(13.29%)compared to those of the asy-ranPBTBDT-based device(0.63 V and 12.22%)in toxic processes with chlorobenzene.The asy-ranPBTBDF-based CQD-SC showed a PCE of 12.51%in a green-solvent process with 2-methylanisole and improved thermal stability at 80℃(83.8%retaining after 24 h)owing to less lateral crystallization than the asy-ranPBTBDT-based device(60.8%retaining after 24 h).
基金This work was supported by the National Natural Science Foundation of China(Nos.61735016,61975172,and 91632105)Zhejiang Provincial Natural Science Foundation of China(Nos.LR17F050001 and LY17C090005)the Fundamental Research Funds for the Central Universities and State Key Laboratory of Pathogenesis,Prevention and Treatment of High Incidence Diseases in Central Asia Fund(No.SKL-HIDCA-2019-3).
文摘It is of great significance to study the brain structure and function in deep-tissue for neuroscience research and bio-medical applications because of the urgent demand for precise theranostics.Three-photon fluorescence microscopic(3PFM)bioimaging excited by the light in near-infrared IIb(NIR-IIb,1,500–1,700 nm)spectral region is one of the most promising imaging techniques with the advantages of high spatial resolution,large imaging depth,and reduced scattering.Herein,a type of NIR-IIb light excitable deep-red emissive semiconducting polymer dots(P-dots)with bright 3PF and large three-photon absorption cross-section(σ3)at 1,550 nm was prepared.Then the P-dots were functionalized with polystyrene polymer polystyrene graft ethylene oxide functionalized with carboxyl groups(PS-PEG-COOH)and modified with NH2-poly(ethylene glycol)(PEG)to synthesis photochemically stable and biocompatible P-dots nanoparticles(NPs).Further the P-dots NPs were utilized for in vivo 3PFM bioimaging of cerebral vasculature with and without the brain skull under 1,550 nm femtosecond(fs)laser excitation.In vivo 3PFM bioimaging of the mice cerebral vasculature at various vertical depths was obtained.Moreover,a vivid three-dimensional structure of the mice vascular architecture beneath the skull was reconstructed.At the depth of 350μm beneath the brain skull,3.8μm blood vessels could still be clearly recognized.NIR-IIb excitable P-dots assisted 3PFM bioimaging has great potential in accurate deep tissue bioimaging.
基金This work was supported by ACS Petroleum Research Fund(PRF#59716-DNI10).
文摘Owing to the outstanding characteristics of tailorable electronic and optical properties,semiconducting polymers have attracted considerable attention in recent years.Among them,organic polymer dots process large breadth of potential synthetic diversity are the representative of photocatalysts for hydrogen production,which presents both an opportunity and a challenge.In this mini-review,first,the organic polymer photocatalysts were introduced.Then,recent reports on polymer dots which showed a superior photocatalytic activity and a robust stability under visible-light irradiation,for hydrogen production were summarized.Finally,challenges and outlook on using organic polymer dots-based photocatalysts from hydrogen production were discussed.
