共轭聚合物发光和光伏材料研究进展

聚合物光电功能材料与器件因其广阔的应用前景,1990年以年来吸引了世界各国学术界的广泛关注和兴趣.聚合物光电子器件主要包括聚合物电致发光二极管、聚合物场效应晶体管和聚合物太阳能电池等,其使用的关键材料是共轭聚合物光电子材料,包括共轭聚合物发光材料、场效应晶体管材料和光伏材料等.本文主要对共轭聚合物电致发光材料和光伏材料的研究进展进行综述,介绍了这些聚合物材料的种类、结构和性质以及在聚合物电致发光器件和聚合物太阳能电池中的应用.并讨论了当前共轭聚合物光电子材料中的关键科学问题和今后的发展方向.     

基于共轭聚合物的近红外光传感器

近红外光(NIR)传感器在军事警戒、空间勘探、科研检测、医疗诊断等领域有着极为重要的应用价值。传统的NIR传感材料主要是基于半金属的无机材料,借助窄带隙来吸收低能量的NIR而改变材料自身的电导率,继而实现检测。无机传感材料由于加工繁琐、不具备柔性、成本高昂以及难降解等因素致其进一步发展受到限制。新兴的共轭聚合物材料通过光热转换或者能级可调的光电效应实现对NIR的高灵敏传感,同时能够实现快速响应。该类聚合物材料具有π电子离域的共轭结构,同样具有较窄的带隙,在NIR照射下能够通过自身电导率的改变或光热转换作用将热量传递至其他超热敏材料来实现对光的检测。借助柔性、环境友好、制备简单、便于掺杂、灵敏度高等优势,共轭聚合物材料为新一代NIR传感器的应用与普及开辟了新的前景。     

Effect and Mechanism of Solvent Properties on Solution Behavior and Films Condensed State Structure for the Semi-rigid Conjugated Polymers

Solvents have an essential association with polymer solution behavior. However, few researches have been deeply done on this respect. In recent years, our research group focus on the study on effect of solvent properties on solution behavior and film condensed state structure for semi-rigid conjugated polymer up till to apply for optoelectronic device. Herein, influence of solvent properties including solubility of solvent, aromaticity, polarity and hydrogen bonds on semi-rigid polymer chain sol...     

Synthesis and photocatalytic activity of TiO2/conjugated polymer complex nanoparticles

A photocatalyst of nanometer TiO2/conjugated polymer complex was successfully synthesized and characterized by spectroscopic methods and photocatalytic experiments. The complex photocatalyst could be activated by absorbing both ultraviolet and visible light （λ = 190-800 nm）. Methylene blue （MB） could be degraded more efficiently on the complex photocatalyst than on the TiO2 under natural light. The conjugated polymer played a promoting role in the photocatalytic degradation of MB. The calcination temperature had an important effect in degradation of dye and could be summarized as 260℃ 〉 300 ℃ 〉 340 ℃ 〉 220 ℃ 〉 180 ℃.     

Realizing high hydrogen evolution activity under visible light using narrow band gap organic photocatalysts

The design and synthesis of conjugated semiconducting polymers for photocatalytic hydrogen evolution have engendered intense recent interest. However, most reported organic polymer photocatalysts show a relatively broad band gap with weak light absorption ability in the visible light region, which commonly leads to a low photocatalytic activity under visible light. Herein, we synthesize three novel dithieno[3,2-b:2′,3′-d]thiophene-S,S-dioxide (DTDO) containing conjugated polymer photocatalysts by a facile C–H arylation coupling polymerization reaction. The resulting polymers show a broad visible light absorption range up to 700 nm and a narrow band gap down to 1.81 eV due to the introduction of the DTDO unit. Benefiting from the donor–acceptor polymer structure and the high content of the DTDO unit, the three-dimensional polymer PyDTDO-3 without the addition of a Pt co-catalyst shows an attractive photocatalytic hydrogen evolution rate of 16.32 mmol h⁻¹ g⁻¹ under visible light irradiation, which is much higher than that of most reported organic polymer photocatalysts under visible light.

Narrow band gap conjugated polymer photocatalysts containing dithieno[3,2-b:2′,3′-d]thiophene-S,S-dioxide show an attractive photocatalytic hydrogen evolution rate of 16.32 mmol h⁻¹ g⁻¹ under visible light irradiation.     

Light‐driven atom transfer radical polymerization on supramolecular complexes of conjugated polymers and single‐walled carbon nanotubes

Previous approaches used to decorate latently reactive conjugated polymer‐coated carbon nanotube complexes have utilized “grafting‐to” strategies. Here, we coat the carbon nanotube surface with a conjugated polymer whose side chains contain the radical initiator, α‐bromoisobutyrate, which enables atom transfer radical polymerization (ATRP) from the polymer–nanotube surface. Using light to generate Cu(I) in situ, ATRP is used to grow narrow dispersity polymer chains from the polymer–nanotube surface. We confirm the successful polymerization of (meth)acrylates from the polymer–nanotube surface using a combination of gel permeation chromatography and infrared spectroscopy. Strikingly, we demonstrate that nanotube optoelectronic properties are preserved after radical‐mediated polymer grafting using Raman spectroscopy and photoluminescence mapping. Overall, this work elucidates a method to grow narrow dispersity polymer chains from the polymer–nanotube surface using light‐driven radical chemistry, with concurrent preservation of nanotube optoelectronic properties. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2015–2020     

共轭聚合物光电探测器研究进展

相较于传统无机半导体材料,有机共轭聚合物半导体具有响应光谱高度可调、质量轻、可大面积制备、与柔性基板兼容等优点,其作为光活性层在下一代可穿戴光电探测器的应用中显示出巨大的应用潜力.共轭聚合物具有多样化的结构设计,不同的分子结构对其光物理化学性能可进行灵活调控,进而展现出各具特色的光电特性.同时,通过结构优化亦可赋予共轭...     

Luminscent graphene quantum dots for organic photovoltaic devices

Recent research in organic photovoltaic (OPV) is largely focused on developing low cost OPV materials such as graphene. However, graphene sheets (GSs) blended conjugated polymers are known to show inferior OPV characteristics as compared to fullerene adduct blended with conjugated polymer. Here, we demonstrate that graphene quantum dots blended with regioregular poly(3-hexylthiophene-2,5-diyl) or poly(2-methoxy-5-(2-ethylhexyloxy)-1,4phenylenevinylene) polymer results in a significant improvement in the OPV characteristics as compared to GSs blended conjugated polymers. This work has implications for inexpensive and efficient solar cells as well as organic light emitting diodes.     

塑料太阳能电池研究进展

塑料太阳能电池是目前国际上比较活跃的研究领域,它具有制备工艺简单、可制备在柔性衬底上、材料的化学结构可调等优点.重点介绍以共轭聚合物-富勒烯衍生物混合物为活性层的体异质结结构塑料太阳能电池研究进展.从活性层薄膜的微观形态结构调控、电极接触界面、光场在电池各层中的空间分布以及叠层结构等几个方面综述了影响塑料太阳能电池效率的因素和提高效率的方法.最后简要介绍了塑料太阳能电池所面临的问题和挑战.     

高效聚合物光伏材料研究进展

聚合物光伏电池因具有重量轻、成本低以及可制成柔性大面积器件等优点而具有广阔的应用前景.近年来,采用共轭聚合物作为光伏电池活性层材料的研究进展十分迅速.本文介绍了聚合物光伏电池的工作原理和器件结构,综述了聚合物材料作为给体,在体相异质结型光伏器件中的最新研究进展,并对今后进一步提高这类电池的能量转换效率问题进行了探讨.     

主链含噁二唑的离子传导型聚对苯乙炔衍生物的合成及发光性能

通过共聚合将噁二唑结构单元引入苯乙炔(PPV)主链,以改进电子注入与传输性能;用离子传导型的聚氧乙烯(PEO)链作为高分子的侧链.用该种聚合物制作的发光二极管(LED)与不含噁二唑的同类结构的共轭聚合物相比,性能明显提高,并制作了发光电池(LEC),对其性能进行初步研究.     

共轭/非共轭嵌段聚苯撑乙烯(PPV)类共聚物的合成与性能

用活性中间体直接引发共轭/非共轭单体聚合的新方法合成了3种PPV嵌段共聚物;用核磁共振谱和FTIR光谱确定了共聚物的结构.引入非共轭片段PS缩短了PPV共轭链的长度,改善了聚合物的溶解性和可加工性.荧光光谱结果表明,嵌段聚合物可使发射峰蓝移,发光的量子效率明显提高,进而调节了发光颜色.     

Solvent-assisted, accelerated photobleaching and fluorescence recovery of conjugated polymer film

The fluorescence of conjugated polymer film was effectively quenched in polar protic solvent upon UV light irradiation and recovered by aging-in-air or reneutralization with amine.     

Organic polymer leds with mobile and immobile ions

The syntheses of partially conjugated alkoxy substituted Poly(p-phenylenevinylene) (PPV) materials with tertiary amines and cationic species covalently bound to the polymer backbone are described. The amine/cationic species are introduced via a polymer analogous reaction of a functional alcohol and the chloro-precursor polymer. Single layer, polymer light emitting diodes (PolyLEDs), prepared with the modified polymer materials show a strong ‘burn-in’ effect, leading to very high electroluminescence (EL) quantum efficiencies especially with higher workfunction cathodes.     

共轭高分子光电功能材料的多尺度性能研究——聚合物电子学领域中的新机遇

共轭高分子材料特异的金属或半导体的电子特性兼有质轻、价廉、易于加工的优点使其在有机场效应晶体管、有机太阳能电池和有机发光二极管等领域显示了重要的应用前景.然而,尽管经过几十年的不断研究,共轭高分子材料种类及其相关器件性能均已得到显著发展,但是共轭高分子材料的本征电荷传输特性仍不清楚,其研究面临巨大挑战,这主要是由共轭高分子材料本身分子量分布弥散、分子间相互缠结以及在常规旋涂薄膜器件中分子高度无序等特性所决定的.从调控共轭高分子聚集态结构的角度出发,不断提高共轭高分子的结构有序性及减小电荷传输过程中的晶界及缺陷密度,是实现共轭高分子材料本征性能认识的有效途径之一.本文首先简单归纳总结了研究者在共轭高分子多尺度聚集态结构调控及性能研究方面的初步结果,进一步结合国内外相关研究进展,重点对共轭高分子晶体方面的工作展开详细介绍,最后对该领域未来发展的挑战及机遇进行了简单评述.     

Highly efficient and stable blue‐light‐emitting binaphthol‐fluorene copolymers: A joint experimental and theoretical study of the main‐chain chirality

In a quest for the main‐chain chiral and highly stable blue‐light‐emitting π‐conjugated polymers, a novel series of soluble conjugated random and alternating copolymers (PF‐BN) derived from fluorene and axially chiral 1,1′‐binaphthol (BINOL) were successfully synthesized by Suzuki coupling polymerization. The polymer structures, optical properties, and their electrochemical properties were investigated by ¹H NMR, TGA/DSC, UV‐Vis absorption, photoluminescence, cyclic voltammetry, circular dichroism spectroscopy, and DFT calculations. The blue‐light‐emitting BINOL‐containing copolymers with proper content of BINOL show highly efficient photoluminescence and ultra highly stable light‐emission with almost unchanged fluorescent spectra after annealing at 200 °C in air for 10 h. The joint experimental and theoretical study of the main‐chain chirality reveals that (1) the chirality of BINOL can be transferred to the polymer backbone, (2) the effective conjugation length is about one BINOL and three fluorenes, (3) the main active chiral block in the copolymers is probably composed by one BINOL with the other two or three fluorenes, and (4) the dihedral angle in the PF‐BN copolymers should be larger than 105°. The incorporation of BINOL into the polyfluorene backbone is an effective way to produce highly efficient and stable blue‐light‐emitting main‐chain chiral conjugated polymer with interesting optoelectronic properties. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3868–3879, 2010     

UV-light mediated decomposition of a polyester for enrichment and release of semiconducting carbon nanotubes

Purification of single-walled carbon nanotubes using conjugated polymers to selectively disperse either semiconducting or metallic nanotubes is effective and has received significant attention. However, the interaction between the conjugated polymer and the nanotube surface is very strong, making it difficult to remove the adsorbed polymer. Here, we report a poly(carbazole-co-terephthalate) polymer that is not only selective for semiconducting carbon nanotubes but can also be largely removed from the nanotube surface via irradiation with UV light. Irradiation of the polymer-nanotube dispersion causes degradation of ester linkages in the polymer backbone, effectively cutting the polymer into fragments that no longer bind strongly to the nanotube surface. Characterization of the electronic nature of the samples was carried out via the combination of absorption, Raman, and fluorescence spectroscopy. In addition, thermogravimetric analysis allowed determination of the amount of polymer left on the nanotube surface after irradiation and indicated that a large proportion of the polymer is removed. The reported methodology opens new possibilities for purification of semiconducting single-walled carbon nanotubes and their isolation from the polymeric dispersant.     

Novel Cross‐Linked Conducting Polythiophene with Yellow‐Green‐Light‐Emitting Properties and Good Thermal Stability

A novel conjugated polythiophene derivative with polymethacrylate attaching to the polymer backbone via an alkyl spacer was successfully synthesized. A methacrylate‐substituted thiophene monomer, 3‐(hexyl methacrylate)thiophene was prepared and polymerized by free radical polymerization, followed by an electrochemical polymerization. The resulting polymer as a yellow‐green‐light emitter, has potential applications in photoelectronics area.     

Macromolecular dynamics of conjugated polymer in donor-acceptor blends with charge transfer complex

Donor-acceptor blends based on conjugated polymers are the heart of state-of-the-art polymer solar cells, and the control of the blend morphology is crucial for their efficiency. As the film morphology can inherit the polymer conformational state from solution, the approaches for probing and controlling the polymer conformational state in the blends are of high importance. In this study, we show that the macromolecular dynamics in solutions of the archetypical conjugated polymer, MEH-PPV, is essentially changed upon addition of an acceptor 2,4,7-trinitrofluorenone (TNF) by using dynamic light scattering (DLS). We have observed four new types of the macromolecular dynamics absent in the parent polymer determined by the polymer and acceptor content. The MEH-PPV?:?TNF ground-state charge-transfer complex (CTC) is suggested to result in these dynamics. In the dilute polymer solution, the CTC formation leads to slower dynamics as compared with the pristine polymer. This is evidence of aggregates formed by intercoil links that are the CTCs involving two conjugated segments of different coils with acceptor molecules being sandwiched between them. At low acceptor content, the aggregates are not stable but at high acceptor content, they are. In the semidilute solution at low acceptor content, the dynamics becomes faster as compared with the pristine polymer that is explained by confinement of the coupled motions of entangled polymer chains. At high acceptor content, the dynamics is far much slower with a characteristic long-range correlation at the scale 3-5 μm that is explained by aggregation of polymer chains in clusters. One can expect that the DLS technique could become a useful tool to study the nano- and microstructure of donor-acceptor conjugated polymer blends to achieve controllable morphology in the corresponding blend films.     

Self organizing polymer films—a route to novel electronic devices based on conjugated polymers

Polymer blends are often used in polymer light emitting diodes as a tool to increase the efficiency of the devices. In this report, we show the necessity to take the phase separation properties of such blends into account, as the miscibility of the involved polymers drastically affects the resulting film structure. By using phase separated polymer blends involving conjugated poly(thiophenes) and different non-conjugated polymers as matrices, different types of applications, such as light emitting diodes with improved voltage control of emitted colour, sub-micron size LEDs and anisotropic conductors are demonstrated.