Aoshu Zhong

Fluorescent and Colorimetric Probes for Mercury(II): Tunable Structures of Electron Donor and π‐Conjugated Bridge

A new series of intramolecular-charge-transfer (ICT) molecules (compounds 1, 2, and 3) were synthesized by attaching various electron-donating thiophenes groups to a triphenylamine backbone with an aldehyde group as the electron acceptor. Based on the protection reaction between ethanethiol and aldehyde, the corresponding dithioacetals (compounds S1, S2, and S3) were prepared to serve as novel colorimetric and fluorescent chemosensors for Hg(2+) ions. Also, compound S1 was further utilized to construct the chemical-reaction-based conjugated polymer probe (PS1) towards Hg(2+) ions. In the presence of as little as 10 nM Hg(2+), compound PS1 displayed an apparent change in the fluorescent intensity. The sensing processes were revealed to be mediated by ICT, as confirmed by time-dependent DFT calculations. Furthermore, compound S1 was successfully applied to microscopic imaging for the detection of Hg(2+) in HeLa cells with ratiometric fluorescent methods.

How the linkage positions affect the performance of bulk-heterojunction polymer solar cells

Two new alternating copolymers. PCT-10,13-BPz (P1) and PCT-2,7-BPz (P2), which were constructed from the same monomers and only different in the connecting points, were synthesized via Suzuki coupling reaction. The UV-vis absorptions, thermal stability, energy levels, field-effect carrier mobility and photovoltaic characteristics of the two copolymers were systematically evaluated to understand the relationships between the polymer structure at the molecular level and the photovoltaic performances. Photovoltaic cells based on the two copolymers with a structure of ITO/PEDOT : PSS/Polymer : PC71BM/PFN/Al exhibited PCEs of 4.31% and 0.64%, respectively, under one sun of AM 1.5 solar simulator illumination (100 mW cm−2).

Synthesis, characterization and photovoltaic performances of D–A copolymers based on BDT and DBPz: the largely improved performance caused by additional thiophene blocks

Two new low bandgap copolymers, PBDT-DBPz and PBDT-DTDBPz, were prepared, in which the only difference was the additional added thiophene bridge between the BDT donor unit and DBPz acceptor unit for PBDT-DTDBPz. In addition to the improvements of UV-vis absorption and hole mobility, the PSC based on PBDT-DTDBPz:PC71BM demonstrated a power conversion efficiency of 4.75%, much higher than that of the device based on PBDT-DBPz:PC71BM (0.46%), under the same experimental conditions.

A New Low-Bandgap Polymer Containing Benzene-Fused Quinoxaline: Significantly Enhanced Performance Caused by One Additional Benzene Ring

Two new alkoxy-substituted quinoxaline (Qx)-based copolymers, PBDTQx and PBDTPz, are designed and synthesized. The only difference between these two polymers is that two methyl groups of the Qx are replaced by one additional fused benzene ring. The UV-Vis absorptions, thermal stability, energy levels, field-effect carrier mobility, and photovoltaic characteristics of the two copolymers are systematically evaluated to understand the relationships between the polymer structure at the molecular level and the photovoltaic performances. Photovoltaic cells based on the PBDTPz with a structure of ITO/PEDOT:PSS/Polymer:PC(71) BM/PEO/Ca/Al exhibit a promising efficiency of 4.40%, while that of PBDTQx is relatively much poorer.

N-arylpyrrole-based chromophores of donor-π-donor type displaying high two-photon absorption.

A series of new N-arylpyrrole-based chromophores with the donor-π-donor structure have been designed and synthesized via Wittig-Horner-Emmons olefination and Suzuki coupling reactions. The electronic and optical properties of the designed chromophores could be well tuned by modifying the conjugation bridges and changing the groups linked to the pyrrole moieties through the C-N single bond. All the chromophores exhibited two-photon absorption activity in the range of 730-900 nm with a large two-photon absorption cross section (∼1000-1700 GM).