Benzothiadiazole(BT) is an electron-deficient unit with fused aromatic core, which can be used to construct conjugated polymers for application in organic solar cells(OSCs). In the past twenty years, huge numbers of conjugated polymers based on BT unit have been developed,focusing on the backbone engineering(such as by using different copolymerized building blocks), side chain engineering(such as by using linear or branch side units), using heteroatoms(such as F, O and S atoms, and CN group), etc. These modifications enable BT-polymers to exhibit distinct absorption spectra(with onset varied from 600 nm to 1000 nm), different frontier energy levels and crystallinities. As a consequence, BT-polymers have gained much attention in recent years, and can be simultaneously used as electron donor and electron acceptor in OSCs, providing the power conversion efficiencies(PCEs) over 18% and 14% in non-fullerene and all-polymer OSCs. In this article, we provide an overview of BTpolymers for OSCs, from donor to acceptor, via selecting some typical BT-polymers in different periods. We hope that the summary in this article can invoke the interest to study the BT-polymers toward high performance OSCs, especially with thick active layers that can be potentially used in large-area devices. 相似文献
Two novel conjugated polymers with alternating main chain structures of zinc porphyrin-terthiophene (P-PTT) and zinc porphyrin-oligothiophene (P-POT) were synthesized by Stille reaction. The effect of different lengths of thiophene chains on the thermal, optical, electrochemical, and photovoltaic properties of the two copolymers were investigated in detail. P-PTT exhibited higher onset decomposition temperature (392 °C) and glass-transition temperature (152 °C) than those of P-POT. The introduction of thiophene units in the meso-aryl positions of porphyrin resulted in the red shift and broader absorption spectrum compared with zinc porphyrin (PZn) monomer both in chloroform solutions and on thin solid films. The electrochemical properties indicated that the energy levels of the polymers were suitable for efficient charge transfer and separation at the interface between the polymer donor and PCBM acceptor. The bulk heterojunction solar cells based on P-PTT and P-POT showed power conversion efficiencies up to 0.32% and 0.18%, respectively. 相似文献
In contrast to edge-on and face-on orientations, end-on uniaxial conjugated polymers have the theoretical possibility of providing a macroscopic crystalline film. However, their fabrication is insurmountable due to sluggishly thermodynamic equilibrium states. Herein, we report the programmatic pathway to fabricate nanoarchitectonics on end-on uniaxial conjugated metallopolymers by surface-initiated simultaneous electrosynthesis and assembly. Self-assembled monolayer (SAM) with bottom-up oriented electroactive molecules as a temple allows orientation, stacking, and reactive addition of monomers triggered by switching alternative redox reactions as well as crystallization of small molecules. Repeating the same reaction can repair the unreactive site on the SAM and dynamically and statistically ensure maximum iterative coverage with ideal linear coefficients between optical or electrical responses and iterative times. The resulting nanoarchitectonics on uniaxially assembled end-on polymers over centimeter-sized areas have a subnanometer-uniform morphology and exhibit ultrahigh modulus as well as an inorganic indium tin oxides and the highest conductance among conjugated molecular monolayers. Their memristive devices provide quantitative electrical and optical responses as a function of molecular length, bias, and iterative junctions. Precise processing of nanoarchitectonics as an electrically assisted assembly or printing technique can present sophisticated optoelectric functions and dimensional batch-to-batch consistency for micro-sized organic materials and electronics. 相似文献
In this article, a versatile 2‐D conjugated polymer, PNDTP‐DPP, containing alkylphenyl substituted naphthodithiophene is synthesized and characterized. PNDTP‐DPP exhibits good solubility and crystallinity with a π−π stacking distance of ≈3.7 Å. Investigation of polymer solar cells (PSCs) and organic field‐effect transistors (OFET) demonstrates a promising power conversion efficiency (PCE) of 4.11% and a high hole mobility of up to 0.86 cm2 V–1 s–1, so this is one of the few examples of versatile polymers that show both good field‐effect mobility and PCE.
