Highly efficient organic solar cells with improved stability enabled by ternary copolymers with antioxidant side chains

The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives are blended as radical scavengers into the active layer.However,it will induce the intrinsic morphology instability and adversely affect the efficiency and long-term stability.Herein,the antioxidant dibutylhydroxytoluene(BHT)group has been covalently linked onto the side chain of benzothiadiazole(BT)unit,and a series of ternary copolymers D18-Cl-BTBHTx(x=0,0.05,0.1,0.2)with varied ratio of BHT-containing side chains have been synthesized.It was found that the introduction of BHT side chains would have a negligible effect on the photophysical properties and electronic levels,and the D18-Cl-BTBHT0.05:Y6-based OSC achieved the highest power conversion efficiency(PCE)of 17.6%,which is higher than those based active layer blended with BHT additives.More importantly,the unencapsulated device based on D18-Cl-BTBHTx(x=0.05,0.1,0.2)retained approximately 50%of the initial PCE over 30 hours operation under ambient conditions,significantly outperforming the control device based on D18-Cl(90%degradation in PCE after 30 h).This work provides a new structural design strategy of copolymers for OSCs with simultaneously improved efficiency and stability.

CHARACTERIZATION OF RADIATION GRAFT COPOLYMER OF INORGANIC COMPOUND ONTO ALKENE

ＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＲＡＤＩＡＴＩＯＮＧＲＡＦＴＣＯＰＯＬＹＭＥＲＯＦＩＮＯＲＧＡＮＩＣＣＯＭＰＯＵＮＤＯＮＴＯＡＬＫＥＮＥＺｈａｎｇＷａｎｘｉ；ＣｈｅＪｉｔａｉ；ＹａｎＭｅｉｌａｎ（ＣｈａｎｇｃｈｕｎｉｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉ...

Synthesis and Flocculation Property of Chitosan-Acrylamide Graft Copolymer

Chitosan, as a kind of natural polymer, has many advantages, such as abundant sources, biological degradation, no secondary contamination and facile modification. In this work, we prepared modified chitosan flocculants with double electrical behavior via polymerizing chitosan, acrylamide and sodium carboxymethyl cellulose together by using ammonium persulfate as the indicator in water. The product is a comb-type of chitosan copolymer and a polymeric ampholyte. And then we studied the product by FTIR, UV-Vis, TG, DSC spectrometeries and viscometry, etc. We also performed CACM′s water treat experiment. The effects of pH values, reaction time and dose of the new floccalant on treating various of waste water have been investigated, too.

Synthesis of Novel Covalent-linked Linear Porphyrin-Thiophene Copolymers

Linear porphyrin-thiophene copolymers were synthesized by linking 5, 15-positions of porphyrin with tetrathiophene or bithiophene moieties for preparing conducting polymer. 2,8,12,18-tetraethyl-3,7,13,17-tetramethyl-5, 15-dithienylporphyrin4a (45.1%), 5, 15-di-bithienyl- 2,8,12,18-tetraethyl-3, 7, 13, 17-tetramethylporphyrin4b (61. 2%) and their metal complexes were also reported in high yields (>90%) as the monomers. 5, 15-di-bithienylporphyrin and its metal complexes could be polymerized by oxidation using FeCl3 as oxidant. However, 5,15-dithienylporphyrin and its metal complexes can not be polymerized by same reaction. Their polymers were synthesized by electrochemical oxidation on the gold-plate electrode. The structures of copolymers were identified by elemental analysis and IR spectra. And the conductivity of poly 5,15-di-bithienylporphyrin was measured to reach over 1.0× 10?6S/cm. Key words organic conductor - thienylporphyrin - porphyrin-thiophene copolymer - electropolymerization CLC number O 62 Foundation item: Supported by the National Natural Science Foundation of China (29872033, 20272046)Biography: CHEN Zhang-ping (1946-), male, Professor, research direction: porphyrin chemistry.

Understanding the Impact of Fluorine Substitution on the Photovoltaic Performance of Block Copolymers

Fluorine substitution was applied to the donor and acceptor segments of block copolymers to understand the impact of molecular structure on photovoltaic block copolymers and explore efficient materials for single-component organic solar cells(SCOSCs).Along this line,three fluorinated block copolymers,namely PBDB-T-b-PTYF6,PM6-b-PTY6,and PM6-bPTYF6,derived from PBDB-T-b-PTY6 were designed and synthesized.The UV-Vis absorption,energy level,and thin-film morphology of these block copolymers were systematically characterized.All fluorinated block copolymers show narrow bandgap and improved crystallinity.An enhanced open-circuit voltage was observed in the SCOSC based on PM6-b-PTY6.However,SCOSCs based on all fluorinated block copolymers exhibited low short-circuit current due to energy level mismatch and therefore had low power conversion efficiency at around 4%.By contrast,the SCOSCs based on control block copolymer PBDB-T-b-PTY6 exhibited the highest power conversion efficiency approaching 10%,with a high short-circuit current of 18.57 mA/cm~2.Our study was the first to perform fluorination on photovoltaic block copolymers and provides insight into precisely controlling the polymer structure and understanding the structure-property relationship in SCOSCs based on block copolymers.

Effect of the Side Chain Structure on Hydrolysis Degradation of Zinc Acrylate Copolymers

In this report,zinc acrylate copolymers were synthesized by used different organic acid as the side chain structure.These copolymers were further characterized by GPC,DSC and Water absorption analysis respectively,and then the effects of the chain structure of organic acid on hydrolysis degradation and copper release rate were also discussed.In the meantime,the result shows that the biocide release rate could be controlled by used different chain structure of organic acid.

A Two-in-One Annealing Enables Dopant Free Block Copolymer Based Organic Solar Cells with over 16% Efficiency

The organic solar cells(OSCs)based on block copolymer systems bear the hope of achieving the optimal balance of power conversion efficiency(PCE)and stability,but the key index,PCE of this type devices is still low.To improve the efficiency,regulating the thin-film morphology is always the core engineering,which is usually achieved via two aspects:precursor optimization and post treatments.

催化氧化催化剂在合成橡胶尾气处理上的应用

以100 kt/a热塑性弹性体装置尾气处理系统为应用对象,对国内自主研发的VOCPlus型催化氧化催化剂进行了性能评价,并考察了其实际应用效果。结果表明,VOCPlus型催化氧化催化剂具有起燃温度低及高温稳定性好和水热稳定性较强的特点。在催化剂入口温度约372℃、反应温度428℃、非甲烷总烃质量浓度1 500 mg/m^(3)的条件下,尾气处理系统反应器出口的非甲烷总烃质量浓度可达6.2 mg/m^(3),总烃去除率维持在99%以上。橡胶装置尾气处理系统至目前已稳定达标运行超过1.5 a,满足该系统对于长周期运行的要求。

Effect of Different Organic Modifiers on the Tensile Properties of PVC/EVA/Montmorillonite Composites

Poly (vinyl chloride)/ethylene-vinyl acetate/montmorillonite (PVC/EVA/OMMT) composites were prepared by melt blending method. Two kinds of montmorillonites were organically modified by trimethyloctadecyl ammonium and dimethyl bis (hydrogenated tallow) ammonium, respectively. The morphology and tensile properties of the resultant composites were discussed in terms of the modifier type and OMMT content. The PVC/EVA/OMMT composites have intercalated structure, which is independent of the polarity of the modifiers, while the tensile properties show strong dependence on the modifier type. The OMMT modified by polar modifier gives higher tensile ductile and strength of PVC/EVA/OMMT composites.

Organic Templates for Inorganic Nanocrystal Growth

Nanocrystals provide a variety of size and shape-dependent properties with applications in a wide range of areas, gaining much attention in the past few years. However, due to the nature of the kinetic nanocrystal growth, the procedures often require strict experimental conditions and the shape and size of nanocrystals are difficult to control. In such context, organic templates, which are artificially modified or synthesized, can direct inorganic nanocrystal nucleation and growth to achieve desired shape, size and ultimately properties. In this review article, two general categories of organic templates used for making inorganic nanomaterials are discussed:biotemplates(e.g., peptide, lipid, DNA, and capsid) and block copolymer templates(e.g., block copolymer micelles, star-like block copolymer unimicelles). The goal of this review is to bridge these gaps and help foster a greater awareness of the range and applicability of different organic templating techniques within the field of nanotechnology.

封装对聚合物太阳能电池性能和稳定性的影响

为了提高有机光伏器件的寿命,通常采用封装技术来限制太阳能电池在水氧中的暴露程度。尽管聚合物太阳能电池(organic solar cells,OSCs)封装领域的相关研究已取得系列进展,但文献中很少研究封装过程带来的损伤。以经典的聚-3已基噻吩为给体,[6,6]-苯基-C_(61)-丁酸甲酯为受体,通过将哌嗪作为第三组分提高器件稳定性,以氧化锌(ZnO)和三氧化钼(MoO_(3))为传输层材料制备倒置结构OSCs,系统考察大规模卷对卷器件封装中常用的紫外线(ultraviolet,UV)固化粘合剂对器件光电转化效率和稳定性的影响。结果表明,随着辐照时间的延长,UV胶封装器件的性能(开路电压、短路电流密度、填充因子和光电转化效率)呈持续下降趋势,更换MoO_(3)/Al电极后老化器件性能恢复,证实MoO_(3)/Al界面破坏是器件性能衰减的重要原因。激光束诱导电流成像显示UV胶封装出现由边缘向中心的失效过程。据此,提出如下的降解机理:UV胶中的光引发剂在紫外光照射下会产生强的质子酸,产生的质子酸与MoO_(3)发生反应,阻碍了空穴的有效传输,最终使得器件效率大幅度下降。此外,还开发出一种有效的OSCs器件用乙烯-醋酸乙烯酯共聚物膜封装工艺。本研究指出了UV胶固化粘合剂封装工艺的问题,同时也为提高聚合物太阳能电池的稳定性提供了新策略。

基于手性聚噻吩嵌段共聚物的圆偏振光探测器

手性有机半导体由于具有光谱可调和易于加工的优点,在小型化和集成化的圆偏振光检测中具有广泛的应用前景。本文通过控制手性异腈(PPI)的加入合成了聚(3-己基噻吩-嵌段-聚(苯基异氰))(P3HT80和P3HT80-PPI(L)30)。实验结果证明了两种半导体聚合物被成功合成。测试了两种半导体聚合物的光学特性,发现嵌段聚合物P3HT80-PPI(L)30具有手性光学活性。制备了基于有机场效应晶体管的圆偏振光探测器,研究器件对于450 nm的圆偏振光旋向的区分性能。实验结果表明,手性异腈(PPI)的加入虽然降低了P3HT80的电学性能,但引入了手性光学活性,使基于P3HT80-PPI(L)30制备的器件能够区分圆偏振光的旋向,并且在450 nm的光电流不对称因子gres达到了0.083。

Regioregular Asymmetric Diketopyrrolopyrrole Copolymers with Good Molecular Ordered Assembly Ability for High-performance Polymer Transistors

Introduction of asymmetric units into conjugated polymers is an important strategy to regulate the photophysical and electronic properties of polymers,as asymmetric units can not only regulate solubility and energy levels,but also molecular stacking and orientation,thus giving much higher optoelectronic properties.However,very few studies have been reported in this field.The semiconducting properties of conjugated polymers could be regulated through regioregularity adjustment.Here,we took the asymmetric thiophene/pyridine side group DPP as core and developed the regioregular monomer T-Py-DPP through three steps:alkyl chain introduction,tin monomer coupling and NBS double bromination.The T-Py-DPP monomer was polymerized into reg-PPy TDPP-2FBT with a head-to-head structure.The regioregularity of T-Py-DPP unit endowed reg-PPy TDPP-2FBT with backbone planarity,self-assembly orientation,network-like morphology and high crystallinity in films,thus the superior bipolar transport properties.The highest hole and electron mobilities of reg-PPy TDPP-2FBT were 0.93 and 0.57 cm^(2)·V^(-1)·s^(-1),respectively,with 40%improvement relative to the regiorandom polymer.

Organic quantum-well characteristics of quasi-one-dimensional copolymers

Copolymers which are synthesized by oligomers or homopolymers have quasi-one-dimen sional structures. A tight-binding model was suggested to study the organic quantum-well properties of triblock copolymers xPA/nPPP/yPA and xPPP/nPA/yPPP consisting of polyacetylene (PA) and poly(p-phenylene) (PPP). It was found that the electronic density in the lowest conductive state ( LU MO) could be tuned by the ratios of homopolymers and interfacial coupling. The spontaneous quantum tunneling effects will occur in triblock copolymer xPA/nPPP/yPA with the increasing interfacial cou pling.

Block copolymers as efficient cathode interlayer materials for organic solar cells

Emerging needs for the large-scale industrialization of organic solar cells require high performance cathode interlayers to facilitate the charge extraction from organic semiconductors.In addition to improving the efficiency,stability and processability issues are major challenges.Herein,we design block copolymers with well controlled chemical composition and molecular weight for cathode interlayer applications.The block copolymer coated cathodes display high optical transmittance and low work function.Conductivity studies reveal that the block copolymer thin film has abundant conductive channels and excellent longitudinal electron conductivity due to the interpenetrating networks formed by the polymer blocks.Applications of the cathode interlayers in organic solar cells provide higher power conversion efficiency and better stability compared to the most widelyapplied ZnO counterparts.Furthermore,no post-treatment is needed which enables excellent processability of the block copolymer based cathode interlayer.

Microporous Organic Nanotube Networks from Hyper Cross-linking Core-shell Bottlebrush Copolymers for Selective Adsorption Study

We report a synthesis of microporous organic nanotube networks（MONNs） by a combination of hyper cross-linking and molecular templating of core-shell bottlebrush copolymers. The intrabrush and interbrush cross-linking of polystyrene（PS） shell layer in the core-shell bottlebrush copolymers led to the formation of micropores and large-sized nanopores（meso/macrospores） in MONNs, respectively, while selective removal of polylactide（PLA） core layer generated mesoporous tubular structure. The size of PLA-templated mesoporous cores and porous structure both at micro-and meso-scale could be controlled by simple tuning of the ratio of core/shell or the PLA core fraction in the bottlebrush precursors. Moreover, the resultant MONNs showed a highly selective adsorption capacity for the positively charged dyes on the basis of multi-porosity and carboxylate group-rich structure. In addition, MONNs also exhibited effective performance in size-selective adsorption of biomacromolecules. This work represents a new avenue for the preparation of MONNs and also provides a new application for molecular bottlebrushes in nanotechnology.

An isoindigo-bithiazole-based acceptor-acceptor copolymer for balanced ambipolar organic thin-film transistors

Balanced carrier transport is observed in acceptor-acceptor (A-A′) type polymer for ambipolar organic thin-film transistors B (OTFTs). It is found that the incorporation of two electron-accepting moieties (BTz and IIG) into a polymer main chain to form A-A′ polymer PIIG-BTz could lower highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels and facilitate good molecular stacking of the polymer. Ambipolar transistor behaviour for PIIG-BTz, with the balanced hole and electron mobilities of 0.030 and 0.022 cm2 V-1 s-1 was observed in OTFT devices, respectively. The study in this work reveals that the utilization of acceptor-acceptor (A-A′) structure in polymer main chain can be a feasible strategy to develop ambipolar polymer semiconductors.

Thieno[3,4-c]pyrrole-4,6-dione based copolymers for high performance organic solar cells and organic field effect transistors

Donor-acceptor type copolymers have wide applications in organic field-effect transistors and organic photovoltaic devices.Thieno[3,4-c]pyrrole-4,6-dione（TPD）,as an electron-withdrawing unit,has been widely used in D-A type copolymers recently.Till now,the highest power conversion efficiency and mobility of TPD-based copolymers are over 8% and 1.0 cm^2 V^（-1） s^（-1） respectively.In this review,the recent progress of TPD-based copolymers in organic solar cells and organic transistors is summarized.

Pervaporation of organic liquid/water mixtures through a novel silicone copolymer membrane

Polydimethylsiloxane-ladder like phenylsilsesquioxane copolymer as a novel membrane material has good film-forming ability, high mechanical properties and low swelling capacity. The copolymer membrane displays the permselectivity of organic liquid for the pervaporation of organic liquid/water mixtures. The pervaporation of aqueous solution of ethanol through the membrane has been investigated. High separation factor can be obtained in the range of low ethanol concentration. The flux of ethanol increases and the flux of water keeps constant as the concentration of ethanol in feed increases. The membrane shows good stability of separation at room temperature to 70℃. The comparison of the pervaporation behavior of the aqueous solutions of methanol, ethanol, 2-propanol, acetone, THF reveals that the magnitude of the separation factors and the fluxes increases in the following order: methanol<ethanol<2-propanol<acetone<THF, in spite of the size of the permeating molecules.

“SiO_2-有机硅”共聚物耐热涂料

通过SiO2 溶胶与有机硅单体进行接枝共聚反应 ,制得了兼有无机物和有机物优点的“SiO2 -有机硅”新型共聚物 ,并配制成耐高温涂料 .固化性能、力学性能和热学性能等测试表明 ,该共聚物涂料比纯有机硅、环氧改性有机硅等传统耐高温涂料具有更高的耐热性和高硬度特性 。