5，8-二呋喃基萘基喹喔啉与对苯撑乙炔交替共聚物的合成及其性能北大核心CSCD

利用Stille耦合反应合成了新型单体5,8-二呋喃基萘基喹喔啉,溴化后与不同长链烷氧基侧链的对苯撑乙炔共聚,合成了聚[2,5-二(辛氧基)-1,4-苯撑乙炔撑-5,8-二(呋喃基)萘基喹喔啉](PⅠ)和聚[2,5-二(十二烷氧基)-1,4-苯撑乙炔撑-5,8-二(呋喃基)萘基喹喔啉](PⅡ)。通过FT-IR、1 H-NMR等手段对单体和共聚物的结构进行了表征,采用紫外-可见吸收光谱、荧光发射光谱和循环伏安法对聚合物的光、电性能进行了探讨。结果表明:单体和共聚物PⅠ、PⅡ在长波处的紫外-可见吸收峰分别为435、418、423nm,相应的荧光发射峰分别为551、589、579nm。2种共聚物均在1.54V处出现氧化峰,无相应的还原峰。     

小分子优先结晶构筑聚合物/非富勒烯共混体系互穿网络结构

非富勒烯小分子受体(SMAs)有序聚集决定聚合物/非富勒烯共混体系光伏电池的双分子复合几率。 然而,由于非对称相分离聚合物趋于优先形成网络,抑制小分子受体分子结晶。 在聚[(2,6-(4,8-二(5-(2-乙基己基噻吩-2-基)苯并[1,2-b:4,5-b']二噻吩))-alt-(5,5-(1',3'-二-2-噻吩基-5',7'-二(2-乙基己基)苯并[1',2'-c:4',5'-c']二噻吩-4,8-二酮))](PBDB-T)/9-二(2-亚甲基(3-(1,1-二氰基亚甲基)-6,7-二氟-茚酮))-5,5,11,11-四(4-己基苯基)-二噻吩并[2,3-d:2',3'-d']-s-引达省[1,2-b:5,6-b']二噻吩(IT-4F)共混体系,四氢呋喃蒸汽处理可提高IT-4F结晶性,150 ℃热退火可提高PBDB-T的结晶性。 因此,依次利用蒸汽退火和热退火处理薄膜,诱导小分子先结晶、聚合物后结晶,从而降低PBDB-T对小分子扩散的限制,构建高结晶互穿网络结构。 形貌优化后降低了双分子复合,器件光电转换效率从5.95%提高至7.18%。     

基于给体-受体型三苯胺喹喔啉类电致变色材料的合成及性能研究

近年来,基于给体-受体(D-A)型共轭聚合物的电致变色器件表现出响应速率快、颜色可调、良好的循环稳定性等诸多优点,受到广泛关注.设计了一类以三苯胺为电子给体,喹喔啉衍生物为电子受体的新型给体-受体-给体(D-A-D)型化合物5,8-二(4-(二苯基氨基)苯基)-2,3-二甲基喹喔啉(Q1)和6,9-二(4-(二苯基氨基)苯基)-1,2,3,4-四氢吩嗪(Q2),通过电化学聚合制备了D-A型聚合物聚(5,8-二(4-(二苯基氨基)苯基)-2,3-二甲基喹喔啉)(PQ1)和聚(6,9-二(4-(二苯基氨基)苯基)-1,2,3,4-四氢吩嗪)(PQ2).研究表明,该类新型的D-A型聚合物在中性时为浅黄色,且随着电压的增大呈现多种颜色变化.该类电致变色材料具有响应时间快、着色效率较高、循环稳定性良好等优点,且其在780 nm附近的最大光学对比度均超过70%,具有潜在的应用价值.     

基于不同长度烷基侧链的s-四嗪基聚合物合成及性能研究

以s-四嗪作为拉电子结构单元(A),以二氟取代四噻吩衍生物作为推电子结构单元(D),并分别以2-己基癸烷基,2-辛基十二烷基,2-癸基十四烷基作为侧链,设计并合成了三种D-A型聚合物光伏材料P(Tet-T16)、P(Tet-T20)和P(Tet-T24)。研究结果表明,具有最短烷基链的聚合物P(Tet-T16)表现出最弱的分子间π-π堆砌,而具有合适长度烷基侧链(2-辛基十二烷基)的聚合物P(Tet-T20)具有最强的分子间相互作用和最有规律的分子堆砌,这更有利于载流子的传输。因此,基于P(Tet-T20)/PC_(71)BM的聚合物太阳能电池器件表现出最佳光伏性能(PCE=5.10%)。同时,由于三种聚合物的HOMO能级都低于-5.56 eV,三种富勒烯PSCs器件的开路电压(V_(oc))均高于1.00 V,其中,基于P(Tet-T24)的PSC表现出1.04 V的高V_(oc)值,这是目前报道的以s-四嗪基聚合物作为给体材料的PSCs中的最高V_(oc)值。但过低HOMO能级与高性能非富勒烯受体的HOMO能级不匹配,限制了其在非富勒烯PSCs中的应用。     

P3HT/非富勒烯受体异质结有机太阳电池

非富勒烯受体材料在分子设计、光吸收及能级等多方面具有极其丰富的可调控性, 使得基于非富勒烯电子受体的本体异质结有机太阳电池(BHJ OSC) 近年得以迅速发展。P3HT聚合物作为被广泛研究的第二代有机半导体材料, 其价格便宜、具有较好的结晶性以及优异的载流子传输性能, 是经典的电子给体材料。本文综述了近年来以P3HT聚合物为给体、非富勒烯类有机化合物为电子受体的有机太阳电池研究进展, 探讨了P3HT/非富勒烯受体BHJ OSC中, 影响器件效率提升的关键因素, 以及电子受体优化设计方面的相应要求。对基于P3HT/非富勒烯受体 BHJ OSC器件的研究前景进行了展望。     

非富勒烯受体DA'D型稠环单元的结构修饰及电池性能研究

近年来,设计和合成高性能非富勒烯受体(NFAs)材料已经成为太阳能电池研究领域的前沿课题。基于DA'D型稠环结构的NFAs由于具有吸光系数高、能级和带隙可调、结构易于修饰、分子可高效合成、光电学性能优异等优点而受到了越来越广泛的关注。在短短7年的时间里,能量转换效率(PCE)从3%~4%提高到18%。2019年初邹应萍等报道了一个优秀的受体分子Y6,与PM6共混制备单结电池,获得了15.7%的能量转换效率。Y6类受体材料的中心给电子单元为DA'D型稠环结构,缺电子单元(A')通过氮原子与两个给电子单元(D)并联形成稠环结构,这有助于降低前线分子轨道能级并增强吸收,同时与氮相连的两个烷基链和位于噻吩并噻吩β位的两个侧链则有助于提高溶解度及调节结晶性。自Y6问世以来,人们对分子的结构剪裁进行了深入的研究,并报道了数十种新的结构。在这些新的受体中,DA'D部分的结构裁剪对提高器件效率和太阳能电池的性能起着至关重要的作用。本文对A'、D单元和侧链结构修饰的研究进展进行了综述。通过选择几组受体,对最近报道的分子进行分类,并将它们的光学、电化学、电学和光电性质与精确的结构修饰相关联,从而对结构-性能关系进行全面概述。     

5，8-二呋喃基萘基喹喔啉与对苯撑乙炔交替共聚物的合成及其性能

利用Stille耦合反应合成了新型单体5,8-二呋喃基萘基喹喔啉,溴化后与不同长链烷氧基侧链的对苯撑乙炔共聚,合成了聚[2,5-二（辛氧基）-1,4苯撑乙炔撑-5,8-二（呋喃基）萘基喹喔啉]（PⅠ）和聚[2,5-二（十二烷氧基）-1,4-苯撑乙炔撑-5,8-二（呋喃基）萘基喹喔啉]（PⅡ）。通过FT—IR、1H—NMR等手段对单体和共聚物的结构进行了表征,采用紫外-可见吸收光谱、荧光发射光谱和循环伏安法对聚合物的光、电性能进行了探讨。结果表明：单体和共聚物PⅠ、PⅡ在长波处的紫外-可见吸收峰分别为435、418、423nm,相应的荧光发射峰分别为551、589、579nm。2种共聚物均在1．54V处出现氧化峰,无相应的还原峰。     

利用相容剂调控聚噻吩/富勒烯共混薄膜形貌

选择含有噻吩环的富勒烯衍生物([6,6]-噻吩基-C61-丁酸甲酯(TCBM-Cn,n代表在噻吩环5位的烷基链碳原子数))作为聚3-己基噻吩(P3HT)和[6,6]-苯基-C61-丁酸甲酯(PCBM)共混体系的相容剂,讨论了结晶能力不同的TCBM-Cn分子对共混体系相容性和P3HT结晶行为的影响.当使用强结晶性的相容剂TCBM-C0时,虽然不能完全抑制PCBM的聚集,但由于分子中噻吩环结构的存在,少量的相容剂即可提高P3HT的结晶度.而对于弱结晶性的相容剂TCBM-C6,虽然可以完全抑制PCBM的聚集,但是只有当其含量超过PCBM时,最终才能达到促进P3HT结晶的目的.     

压力和酸响应的四苯乙烯修饰喹喔啉类荧光染料的合成与性质研究

合成了新的给受体型四苯乙烯修饰的喹喔啉衍生物BTPQ、DBTPQ和BTBQ.三个化合物表现出不同程度的聚集诱导发光(AIE)行为,当BTBQ (四苯乙烯单元修饰在喹喔啉的2,3-位)的四氢呋喃溶液中含水量达到90%时,其荧光发射强度增加至原来的54倍.此外,固体BTBQ在三氟乙酸蒸气作用下可由淡黄色变成红色,且其蓝绿色荧光被显著猝灭,可见,它可作为传感材料用于酸蒸气的可视化检测.由于连接在喹喔啉5,8-位上的四苯乙烯单元的空阻作用导致BTPQ和DBTPQ不易被质子化,因此,二者对酸不敏感,但是,它们的固态发光颜色在研磨前后发生了明显变化,如,BTPQ在结晶态时发射蓝色荧光,经研磨变成无定形态后,发射蓝绿色荧光, BTPQ和DBTPQ的压致荧光变色行为在研磨、加热/溶剂熏蒸处理下具有可逆性.     

基于苊并[1,2-b]喹喔嗪为受体单元设计合成新型红光热活化延迟荧光分子

采用苊并[1,2-b]喹喔嗪(AQ)作为一种新的热活化延迟荧光(TADF)电子受体(A)基团,通过与强电子给体(D)基团吩噁嗪连接成D-A结构,合成出一种新型TADF分子10,10',10'-(苊并[1,2-b]喹喔嗪-3,9,10-三基)-三(10H-吩噁嗪)(AQ-TPXZ),该分子材料发射红色荧光.理论计算表明,该分子的轨道电子云重叠度很小.通过荧光和磷光光谱计算得出,其单线态-三线态能隙差为0.02eV.瞬态衰减测试显示AQ-TPXZ具有瞬时寿命和延迟寿命两种组分.以AQ-TPXZ为发光材料的有机电致发光器件(OLED)实现了红光发射,峰值位于624nm处.该器件的最大外量子效率为7.4%,高于传统的OLED的理论最大外量子效率(5%),这一结果不仅表明AQ-TPXZ为红光TADF分子,同时表明AQ可作为一种新的红光TADF电子受体片段.     

Perylene and naphthalene diimide copolymers for all-polymer solar cells: Effect of perylene/naphthalene ratio

We report the synthesis of a series of copolymers, having 2,2′-bithiophene as electron-donating moiety, and perylene diimide (PDI) and/or naphthalene diimide (NDI) as electron-accepting moiety, and employed as non-fullerene acceptors in polymer solar cells (PSCs). All the copolymers show wide absorption varying from 300 to 850 nm in the visible and NIR spectrum. When changing the PDI/NDI ratio in the polymer backbone, The LUMO energy levels vary in the range of −3.90 to −3.80 eV and the HOMO energy levels vary in the range of −6.10 to −5.85 eV. Among PSCs based on PTB7-Th donor and these polymer acceptors, the devices based on PTB7-Th/NDI100 yield the best power conversion efficiency (PCE) of 4.67%, while the PTB7-Th/PDI100-based devices yield a PCE of 1.03%. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 682–689     

A chlorinated non-fullerene acceptor for efficient polymer solar cells

After additive and thermal annealing treatment, the PM6:Y15 based device obtains a high power conversion efficiency of 14.13%.     

非富勒烯聚合物太阳电池研究进展

综述了以p-型共轭聚合物为给体、n-型有机半导体为受体的非富勒烯聚合物太阳电池光伏材料最新研究进展,包括n-型共轭聚合物和可溶液加工小分子n-型有机半导体(n-OS)受体光伏材料,以及与之匹配的p-型共轭聚合物给体光伏材料.介绍的n-型共轭聚合物受体光伏材料包括基于苝酰亚胺(BDI)、萘酰亚胺(NDI)以及新型硼氮键连受体单元的D-A共聚物受体光伏材料,目前基于聚合物给体(J51)和聚合物受体(N2200)的全聚合物太阳电池的能量转换效率最高达到8.26%.n-OS小分子受体光伏材料包括基于BDI和NDI单元的有机分子、基于稠环中心给体单元的A-D-A型窄带隙有机小分子受体材料等.给体光伏材料包括基于齐聚噻吩和苯并二噻吩(BDT)给体单元的D-A共聚物,重点介绍与窄带隙A-D-A结构小分子受体吸收互补的、基于噻吩取代BDT单元的中间带隙二维共轭聚合物给体光伏材料.使用中间带隙的p-型共轭聚合物为给体、窄带隙A-D-A结构有机小分子为受体的非富勒烯聚合物太阳电池能量转换效率已经突破12%,展示了光明的前景.最后对非富勒烯聚合物太阳电池将来的发展进行了展望.     

Side-chain engineering of high-efficiency conjugated polymer photovoltaic materials

In recent years,conjugated polymers have attracted great attention in the application as photovoltaic donor materials in polymer solar cells(PSCs).Broad absorption,lower-energy bandgap,higher hole mobility,relatively lower HOMO energy levels,and higher solubility are important for the conjugated polymer donor materials to achieve high photovoltaic performance.Side-chain engineering plays a very important role in optimizing the physicochemical properties of the conjugated polymers.In this article,we review recent progress on the side-chain engineering of conjugated polymer donor materials,including the optimization of flexible side-chains for balancing solubility and intermolecular packing(aggregation),electron-withdrawing substituents for lowering HOMO energy levels,and two-dimension(2D)-conjugated polymers with conjugated side-chains for broadening absorption and enhancing hole mobility.After the molecular structural optimization by side-chain engineering,the2D-conjugated polymers based on benzodithiophene units demonstrated the best photovoltaic performance,with powerconversion efficiency higher than 9%.     

Narrow bandgap semiconducting polymers for solar cells with near-infrared photo response and low energy loss

The alternating diketopyrrolopyrrole (DPP)-Quinoxaline (Qx) based conjugated polymers are synthesized and investigated as electron donors for polymer solar cells (PSCs). Through the substitution of phenyl in Qx unit at para (p) and meta (m) positions with methoxy group, the resultant DPP-pMQx and DPP-mMQx polymers possess narrow optical band gap (1.32 and 1.26 eV) with relatively low-lying highest occupied molecular orbitals. The obtained photovoltaic devices indicate that the combination of DPP with weak acceptor Qx is helpful to develop narrow bandgap polymers with near-infrared photo response and low energy loss (0.58 eV for DPP-mMQx) in PSC devices.     

基于一种新型聚噻吩衍生物为给体的非富勒烯聚合物太阳能电池

With the development of non-fullerene small-molecule acceptors, non-fullerene polymer solar cells (PSCs) have garnered increased attention due to their high performance. While photons are absorbed and converted to free charge carriers in the active layer, the donor and acceptor materials both play a critical role in determining the performance of PSCs. Among the various conjugated-polymer donor materials, polythiophene (PT) derivatives such as poly(3-hexylthiophene), have attracted considerable interest due to their high hole mobility and simple synthesis. However, there are limited studies on the applications of PT derivatives in non-fullerene PSCs. Fabrication of highly efficient non-fullerene PSCs utilizing PT derivatives as the donor is a challenging topic. In this study, a new PT derivative, poly[5, 5′-4, 4′-bis(2-butyloctylsulphanyl)-2, 2′-bithiophene-alt-5, 5′-4, 4′-difluoro-2, 2′-bithiophene] (PBSBT-2F), with alkylthio groups and fluorination was synthesized for use as the donor in non-fullerene PSC applications. The absorption spectra, electrochemical properties, molecular packing, and photovoltaic properties of PBSBT-2F were investigated and compared with those of poly(3-hexylthiophene) (P3HT). The polymer exhibited a wide bandgap of 1.82 eV, a deep highest occupied molecular orbital (HOMO) of -5.02 eV, and an ordered molecular packing structure. Following this observation, PSCs based on a blend of PBSBT-2F as the donor and 3, 9-bis(2-methylene-(3-(1, 1-dicyanomethylene)-indanone)-5, 5, 11, 11-tetrakis(4-hexylphenyl)-dithieno-[2, 3-d:2′, 3′-d′]-s-indaceno[1, 2-b:5, 6-b′]dithiophene (ITIC) as the acceptor were fabricated. The absorption spectra were collected and the energy levels were found to be well matched. These devices exhibited a power conversion efficiency (PCE) of 6.7% with an open-circuit voltage (V_OC) of 0.75 V, a short-circuit current density (J_SC) of 13.5 mA·cm^-2, and a fill factor (FF) of 66.6%. These properties were superior to those of P3HT (1.2%) under the optimal conditions. This result indicates that PBSBT-2F is a promising donor material for non-fullerene PSCs.     

Alkoxy substituted benzodithiophene-alt-fluorobenzotriazole copolymer as donor in non-fullerene polymer solar cells

A new benzodithiophene(BDT)-alt-fluorobenzotriazole(FBTA) D-A copolymer J40 was designed and synthesized by introducing 2-octyldodecyloxy side chains on its BDT units, for expanding the family of the BDT- alt-FBTA-based copolymers and investigating the side chain effect on the photovoltaic performance of the polymer in non-fullerene polymer solar cells(PSCs).J40 exhibits complementary absorption spectra and matched electronic energy levels with the n-type organic semiconductor(n-OS)(3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-sindaceno[1,2-b:5,6-b′]dithiophene)(ITIC) acceptor, and was used as polymer donor in the non-fullerene PSCs with ITIC as acceptor. The power conversion efficiency(PCE) of the PSCs based on J40:ITIC(1:1, w/w) with thermal annealing at 120 °C for 10 min reached 6.48% with a higher open-circuit voltage(Voc) of 0.89 V. The high Voc of the PSCs is benefitted from the lower-lying highest occupied molecular orbital(HOMO) energy level of J40. Although the photovoltaic performance of the polymer J40 with alkoxy side chain is lower than that of J60 and J61 with alkylthio-thienyl conjugated side chains, the PCE of6.48% for the J40-based device is still a relatively higher photovoltaic efficiency in the non-fullerene PSCs reported so far. The results indicate that the family of the BDT-alt-FBTA-based D-A copolymers are high performance polymer donor materials for non-fullerene PSCs and the side chain engineering plays an important role in the design of high performance polymer donors in the non-fullerene PSCs.     

The Crucial Role of Chlorinated Thiophene Orientation in Conjugated Polymers for Photovoltaic Devices

Chlorinated conjugated polymers not only show great potential for the realization of highly efficient polymer solar cells (PSCs) but also have simple and high‐yield synthetic routes and low‐cost raw materials available for their preparation. However, the study of the structure–property relationship of chlorinated polymers is lagging. Now two chlorinated conjugated polymers, PCl(3)BDB‐T and PCl(4)BDB‐T are investigated. When the polymers were used to fabricate PSCs with the nonfullerene acceptor (IT‐4F), surprisingly, the PCl(3)BDB‐T:IT‐4F‐based device exhibited a negligible power conversion efficiency (PCE) of 0.18 %, while the PCl(4)BDB‐T:IT‐4F‐based device showed an outstanding PCE of 12.33 %. These results provide new insight for the rational design and synthesis of novel chlorinated polymer donors for further improving the photovoltaic efficiencies of PSCs.     

Effects of Bithiophene Imide Fusion on the Device Performance of Organic Thin‐Film Transistors and All‐Polymer Solar Cells

Two new bithiophene imide (BTI)‐based n‐type polymers were synthesized. f‐BTI2‐FT based on a fused BTI dimer showed a smaller band gap, a lower LUMO, and higher crystallinity than s‐BTI2‐FT containing a BTI dimer connected through a single bond. s‐BTI2‐FT exhibited a remarkable electron mobility of 0.82 cm² V⁻¹ s⁻¹, and f‐BTI2‐FT showed a further improved mobility of 1.13 cm² V⁻¹ s⁻¹ in transistors. When blended with the polymer donor PTB7‐Th, f‐BTI2‐FT‐based all‐polymer solar cells (all‐PSCs) attained a PCE of 6.85 %, the highest value for an all‐PSC not based on naphthalene (or perylene) diimide polymer acceptors. However, s‐BTI2‐FT all‐PSCs showed nearly no photovoltaic effect. The results demonstrate that f‐BTI2‐FT is one of most promising n‐type polymers and that ring fusion offers an effective approach for designing polymers with improved electrical properties.     

Perylene Diimide Hexamer Based on Combination of Direct and Indirect Linkage Manners for Non-fullerene Organic Solar Cells

Perylene diimide (PDI) is one of the most intensively studied building blocks for the construction of non-fullerene acceptors (NFAs). In this contribution, based on combination of the direct and indirect linkage manners of PDI units at the bay position, a propeller-shaped PDI hexamer T-DPDI was designed and synthesized. The singly bonded PDI dimer DPDI and the benzene ring cored PDI trimer TPDI were synthesized for comparison. The photovoltaic performances of these three PDI derivatives were investigated using the commercially available PTB7-Th as electron donor. A best power conversion efficiency (PCE) of 6.58% was obtained for T-DPDI based organic solar cells (OSCs), which is higher than those of DPDI and TPDI based ones. The superior photovoltaic performance of T-DPDI can be ascribed to its stronger absorption and more favorable morphology. This study presents an interesting example of improving the photovoltaic performances of PDI based NFAs by hybridizing the direct and indirect linkage manners.