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Conjugated polymers with well-balanced ambipolar charge transport is essential for organic circuits at low cost and large area with simplified fabrication techniques. Aiming at this point, herein, a novel asymmetric thiophene/pyridine-flanked diketopyrrolopyrrole-based copolymer (PPyTDPP–2FBT) is designed and synthesized. Due to the effect of incorporating F atoms on molecular energy alignment and conjugation conformation, the PPyTDPP–2FBT copolymer exhibits typical V-shaped ambipolar field-effect transfer characteristics with well-balanced hole and electron mobilities of 0.64 and 0.46 cm2 V−1 s−1, respectively. Furthermore, organic digital and analog circuits such as inverters and frequency doublers are successfully constructed based on solution-processed films of the PPyTDPP–2FBT copolymers which show a typical circuit operating mode with a high gain of 133 due to the well-balanced electrical properties. In addition, PPyTDPP–2FBT-based devices also demonstrate good stability and batch repeatability, suggesting their great potential applications in organic integrated electronic circuits.

In this article, an acid-responsive luminescent material, 1,4-di(quinoline-6-yl)buta-1,3-diyne (DQBD) is designed and synthesized. Upon different pH values, gradual changes of fluorescence colors for DQBD in both solution and solid phases are demonstrated due to the protonation effect. Moreover, such responsive characteristics can also be reversible, suggesting DQBD as a promising fluorescent material with great potential for reusable- and accurate-pH sensors in the future.

二维共轭聚合物具有平面共轭结构和分子中离域的π电子体系, 因而具有很强的平面内电荷传输能力, 表现出独特的物理和化学性质, 在光学、电学、传感等领域具有广阔的应用前景. 但如何获得分子结构及形貌符合二维特征、且尺寸满足制作电子器件需求的分子非常困难, 是广大科研人员急需解决的问题. 本文总结了界面合成二维共轭聚合物的方法, 讨论了这个领域目前面临的问题和挑战, 并指出了未来的研究方向.

There is very limited repertoire of organic ambipolar semiconductors to date. Electron donor-acceptor alternative stacking is a unique and important binary motif for 1D mixed-stack cocrystals, opening up possibilities for the development of organic ambipolar semiconductors. Herein, four 1D mixed-stack cocrystals using N,N'-bis(perfluorobutyl)-1,7-dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDICNF) as the acceptor and anthracene, pyrene, perylene, and meso-diphenyl tetrathia[22]annulene[2,1,2,1] (DPTTA) as the donors are achieved in a stoichiometric ratio (D:A = 1:1) through solution or vapor processed methods. Their packing structures, energy levels, charge transfer interactions, coassembling behaviors, and molecular orientations are systematically investigated by single-crystal X-ray analysis, absorption spectra, fluorescence quenching, Job's curve plot, and polarized photoluminescence measurements with the help of theoretical calculations. The donor-acceptor alternative stacking direction coincides with the long axis for all the four cocrystals. The field-effect transistors based on Pyrene-PDICNF show the electron mobility up to 0.19 cm2 V-1 s-1 , which is the highest value among perylene diimide-based cocrystals. Moreover, DPTTA-PDICNF cocrystals possess well-balanced electron and hole mobility with 1.7 × 10-2 and 2.0 × 10-2 cm2 V-1 s-1 respectively due to both hole and electron strong superexchange interactions, shedding light on the design of 1D mixed-stack cocrystals with excellent ambipolar transport behaviors.

Preparing two-dimensional conjugated polymers (2DCPs) with desirable structures and semiconducting properties is promising but remains a great challenge. Presented here is a new 2DCP, named 2D polytriethyltriindole (2DPTTI), which is efficiently synthesized by a modified interfacial Suzuki reaction from 2,7,12-tribromo-5,10,15-triethyltriindole (2-BrTTI) and 1,4-benzenediboronic acid dipinacol ester (BADE) precursors at room temperature. Wafer-scale free-standing 2DPTTI films with controllable thicknesses between 2.5 and 46.0 nm were obtained by adjusting the experimental conditions. The resulting 2DPTTI films, used as an active layer in organic field effect transistors (OFETs), exhibited typical p-type semiconducting properties and superior UV optoelectronic performance with a photosensitivity of 3.7×103 and responsivity of 1.4×103 A W-1 , as well as a light-blue fluorescence character. This report provides a general approach for constructing various semiconducting 2DCPs, by an interfacial Suzuki reaction, towards multifunctional organic electronics.

This study investigated the strain and damage self-sensing capabilities of basalt fiber reinforced polymer (BFRP) laminates fabricated with carbon nanofibers (CNFs)/epoxy composites subjected to tensile loadings. The conduction mechanisms based on the tunnel conduction and percolation conduction theories as well as the damage evolution were also explored. A compensation circuit with a half-bridge configuration was proposed. The results indicated the resistivity of the CNFs/BFRP laminates and CNFs/epoxy composites exhibited similar change rule, indicating that the conductive networks of CNFs/BFRP laminates were governed by CNFs/epoxy composites. With the increase of strain under monotonic tensile loading, the electrical resistance response could be classified into three stages corresponding to different damage modes. This confirmed CNFs/BFRP laminates have excellent self-sensing abilities to monitor their internal damages. Moreover, stable and repeatable strain self-sensing capacity of the CNFs/BFRP laminates was verified under cyclic tensile loading because the electrical resistance varied synchronously with the applied strain.

Sodium-ion hybrid supercapacitors have received great attracts for next-generation energy storage applications due to their high energy and power densities, as well as the abundant sodium resource. However, electrodes based on transition-metal oxides often suffer from low reversible capacity and sluggish redox kinetics, which seriously constrains the rate and cycling performance of the devices. Herein, a facile two-step hydrolysis synthesis is used to prepare uniform sandwich-like mesoporous Nb2O5/graphene/mesoporous Nb2O5 (G@mNb2O5) nanosheets as sodium storage materials. The mesoporous Nb2O5 layers on graphene are constructed by several nanometer-sized Nb2O5 particles. In virtue of the structural features, the G@mNb2O5 nanosheets electrode demonstrates high-rate capacity (293 and 125 mA h g−1at 50 and 2000 mA g−1, respectively) and stable cycling performance due to the rapid redox kinetics, including significantly increased surface pseudocapacitive contribution, improved sodium-ion diffusion coefficient, and short characteristic relaxation process. By employing activated carbon as cathode, a full sodium-ion hybrid device successfully demonstrates a high energy density of 56.1 Wh kg−1 at 120 W kg−1, and 9.7 Wh kg−1 at 7200 W kg−1, as well as a stable capacitance retention of ∼ 89% at 1 A g−1. The availability of capacitive Na-ion storage system presented here is attractive for cost-effective energy storage applications.

In this study, one new rare-earth lanthanum(Ⅲ) metal-organic coordination polymer {[La(L)1.5(H2O)(DMF)]∙DMF}n (H2L = 4,4’-(diethynylanthracene-9,10-diyl) dibenzoic acid) labeled as La-CP was successfully constructed via a solvothermal process. Structure analysis of the obtained La-CP revealed that it crystallized in the triclinic space group P-1, in which each La3+ ion was coordinated to eight oxygen atoms to form a distorted square antiprism geometry. It was important to observe π-π stacking between adjacent ligand moieties of La-CP with face-to-face distances of 3.385 and 3.447 A, endowing charge carriers with the possibility of through-space transport. The optical band gap of 2.23 eV evaluated from the UV-vis diffuse reflectance spectrum, coupled with electronic band structure calculation, provided reliable evidence of its potential semiconductor characteristic. In addition, La-CP exhibited a yellow fluorescence emission and a comparable quantum yield of 1.81% to that of free ligand H2L in terms of its optical properties. This work not only expands the list of rare-earth lanthanide coordination polymers but also offers useful guidance for materials design and related properties modulation of coordination polymers to some extent.