Publications by authors named "Kailong Wu"

Food security is a global issue, since it is closely related to human health. Antibiotics play a significant role in animal husbandry owing to their desirable broad-spectrum antibacterial activity. However, irrational use of antibiotics has caused serious environmental pollution and food safety problems; thus, the on-site detection of antibiotics is in high demand in environmental analysis and food safety assessment.

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Developing excited-state intramolecular proton transfer (ESIPT) emitters with high photoluminescence quantum yields (Φs) and long fluorescence lifetimes in solid state remains a formidable challenge. In this study, we integrated the molecular design tactics of thermally activated delayed fluorescence (TADF) into ESIPT molecules with the goals of improving their Φs and increasing their fluorescence lifetimes. Two proof-of-concept molecules, PXZPDO and DMACPDO, were developed by adopting symmetric D-π-A-π-D molecular architectures (where D and A represent donors and acceptors, respectively) featuring electron-donating phenoxazine or a 9,9-dimethyl-9,10-dihydroacridine moiety, an ESIPT core β-diketone, and phenylene π-bridges.

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In this work, an effectual strategy of constructing polar small molecule acceptors (SMAs) to promote fill factor (FF) of nonfullerene polymer solar cells (PSCs) is first reported. Three asymmetrical SMAs of IDT6CN, IDT6CN-Th, and IDT6CN-M, which own large dipole moments, are designed and synthesized. The PSCs based on three polar SMAs exhibit apparently higher FFs compared with their symmetrical analogues.

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Two new blue emitters, i.e., bis-[2-(9,9-dimethyl-9,10-dihydroacridine)-phenyl]-sulfone ( o-ACSO2) and bis-[3-(9,9-dimethyl-9,10-dihydroacridine)-phenyl]-sulfone ( m-ACSO2), with reserved fine thermally activated delayed fluorescent (TADF) nature and simply tuned thermal and optoelectronic properties, were synthesized by isomer engineering.

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A novel small molecule acceptor MeIC with a methylated end-capping group is developed. Compared to unmethylated counterparts (ITCPTC), MeIC exhibits a higher lowest unoccupied molecular orbital (LUMO) level value, tighter molecular packing, better crystallites quality, and stronger absorption in the range of 520-740 nm. The MeIC-based polymer solar cells (PSCs) with J71 as donor, achieve high power conversion efficiency (PCE), up to 12.

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Two new non-fullerene acceptors, IDTC and IDTO, were designed and synthesized for the application in organic solar cells (OSCs). Compared with IDTC, the introduction of electron-donating alkoxy groups of IDTO leads to a higher LUMO level with a slightly blue-shifted absorption. Using the polymer PBDB-T as donor and the two small molecules as acceptors in the conventional device structure, the IDTC-based OSC exhibits a power conversion efficiency (PCE) of 9.

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Thermally activated delayed fluorescence (TADF) polymers are designed and synthesized by grafting the TADF emitter to the side chain of the polycarbazole backbone. By employing these TADF polymers with large ratio of delayed fluorescence component and high photoluminescence quantum yield as the emitters, the solution-processed light-emitting diodes achieve a maximal external quantum efficiency of 16.1% at a luminance of around 100 cd m .

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Two new polymers, and , are synthesized through copolymerization of 4-(2-octyldodecyl)-dithieno[3,2-:2',3'-]pyridin-5(4)-one () with indacenodithiophene () or indacenodithieno[3,2-]thiophene (). The rational combination of the planar unit with ladder-type and units endows the resulting copolymers with wide optical bandgaps of 2.05 eV, low HOMO energy levels of -5.

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We have developed two new carbazole-dendronized emitters based on a green emissive thermally activated delayed fluorescence (TADF) core. Both dendrimers possess excellent thermal stability, good solution processability, and an obvious TADF feature. Non-doped OLEDs based on the emitters formed by a solution process exhibit a maximum external quantum efficiency (EQE) of 13.

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A series of green butterfly-shaped thermally activated delayed fluorescence (TADF) emitters, namely PXZPM, PXZMePM, and PXZPhPM, are developed by integrating an electron-donor (D) phenoxazine unit and electron-acceptor (A) 2-substituted pyrimidine moiety into one molecule via a phenyl-bridge π linkage to form a D-π-A-π-D configuration. Changing the substituent at pyrimidine unit in these emitters can finely tune their emissive characteristics, thermal properties, and energy gaps between the singlet and triplet states while maintaining frontier molecular orbital levels, and thereby optimizing their optoelectronic properties. Employing these TADF emitters results in a green fluorescent organic light-emitting diode (OLED) that exhibits a peak forward-viewing external quantum efficiency (EQE) close to 25 % and a slow efficiency roll-off characteristic at high luminance.

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An adamantane-based host material, namely, 4-{3-[4-(9H-carbazol-9-yl)phenyl]adamantan-1-yl}benzonitrile (CzCN-Ad), was prepared by linking an electron-donating carbazole unit and an electron-accepting benzonitrile moiety through an adamantane bridge. In this approach, two functional groups were attached to tetrahedral points of adamantane to construct an "sp(3)" topological configuration. This design strategy endows the host material with a high triplet energy of 3.

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