Publications by authors named "Ning-Jiu Zhao"

Colloidal quantum dots (QDs) have demonstrated great promise in artificial photosynthesis. However, the ultrasmall size hinders its controllable and effective interaction with cocatalysts. To improve the poor interparticle electronic communication between free QD and cocatalyst, we design here a self-assembled architecture of nanoparticles, QDs and Pt nanoparticles, simply jointed together by molecular polyacrylate to greatly enhance the rate and efficiency of interfacial electron transfer (ET).

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A pair of 9-arylidene-9H-fluorene and benzothiadiazole based, low-bandgap copolymers differing merely in the para or meta substitution of alkoxy groups to the arylidene linkages, i.e. p-PAFDTBT and m-PAFDTBT respectively, were comparatively investigated by using morphological characterization, ultrafast spectroscopy and quantum chemical calculations.

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The excited-state properties and chain conformations of a new low-bandgap copolymer based on benzo[1,2-b:4,5-b']dithiophene (BDT) and thieno[3,4-b]thiophene with meta-alkoxyphenyl-substituted side chains in solution were investigated comprehensively. Time-resolved spectroscopy suggested that the excited-state properties were sensitive to the conformations of the copolymer in solution. In addition, excited-state dynamics analyses revealed the photogeneration of triplet excited states by intersystem crossing (ISC) at a rate constant of ∼0.

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The installation of heterojunctions on the surfaces of carbon nanotubes (CNTs) is an effective method for promoting the charge separation processes needed for CNT-based electronics and optoelectronics applications. Conjugated polymers are proven state-of-the-art candidates for modifying the surfaces of CNTs. However, all previous attempts to incorporate conjugated polymers to CNTs resulted in unordered interfaces.

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The photosynthetic purple bacterium Thermochromatium (Tch.) tepidum is a thermophile that grows at an optimal temperature of ∼50 °C. We have investigated, by means of steady-state and time-resolved optical spectroscopies, the effects of temperature on the near-infrared light absorption and the excitation energy transfer (EET) dynamics of its light-harvesting complex 2 (LH2), for which the mesophilic counterpart of Rhodobacter (Rba.

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Solution-phase conformations and charge photogeneration dynamics of a pair of low-bandgap copolymers based on benzo[1,2-b:4,5-b(')]dithiophene (BDT) and thieno[3,4-b]thiophene (TT), differed by the respective carbonyl (-C) and ester (-E) substituents at the TT units, were comparatively investigated by using near-infrared time-resolved absorption (TA) spectroscopy at 25 °C and 120 °C. Steady-state and TA spectroscopic results corroborated by quantum chemical analyses prove that both PBDTTT-C and PBDTTT-E in chlorobenzene solutions are self-aggregated; however, the former bears a relatively higher packing order. Specifically, PBDTTT-C aggregates with more π-π stacked domains, whereas PBDTTT-E does with more random coils interacting strongly at the chain intersections.

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Article Synopsis
  • Ultrafast near-infrared absorption spectroscopy was employed to study how film structure and photon energy affect charge recombination (CR) dynamics in P3HT/PC(61)BM blend films.
  • Solvent vapor annealed (SVA) films showed significant improvements in hole mobility and reductions in localized trap states compared to CS(2)-cast films.
  • Higher hole concentrations led to a quicker increase in hole mobility under above-gap photoexcitation, emphasizing the need to utilize photogenerated free charges at early timescales.
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Synopsis of recent research by authors named "Ning-Jiu Zhao"

  • Ning-Jiu Zhao's research focuses on enhancing the efficiency of photovoltaic materials and systems through innovative structural designs and understanding excited-state dynamics of polymeric materials.
  • His studies explore the impact of molecular architecture, like self-assembled frameworks, on improving electronic communication in nanomaterials for solar hydrogen evolution and energy transfer in light-harvesting complexes.
  • Zhao's work also investigates the effects of side-chain substitutions in low-bandgap copolymers, revealing how these modifications influence charge generation, morphology, and photophysical properties in solution.