窄带隙二噻吩并吡咯共聚物合成与光伏性能研究  

Synthesis and Photovoltaic Performance of Low Band Gap Dithieno[3,2-b:2′,3′-d]pyrrole-based Conjugated Copolymers

作　　者：任静[1] 陈伟业 李枫[3] 王玮[1] 阳仁强[2] 孙明亮[1] Jing Ren1, Wei-ye Chen1,2, Feng Li3, Wei Wang1, Ren-qiang Yang2, Ming-liang Sun1(1.School of Materials Science and Engineering, Ocean University of China, Qingdao 266100;2.Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy Sciences, Qingdao 266101;3.School of Polymer Science and Engineering, Qingdao University of Science ＆ Technology, Qingdao 26604)

机构地区：[1]中国海洋大学材料科学与工程学院,青岛266100 [2]中国科学院青岛生物能源与过程研究所,青岛266101 [3]青岛科技大学高分子科学与工程学院,青岛266042

出　　处：《高分子学报》2018年第4期456-463,共8页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21274134)资助项目

摘　　要：二噻吩[3,2-b:2′,3′-d]并吡咯(Dithieno[3,2-b:2′,3′-d]pyrrole,DTP)分别与3种受体单元聚合得到聚合物P1~P3,受体单元分别为:吡咯并吡咯二酮(DPP)、二噻吩苯并噁二唑(DTBO)和喹喔啉衍生物(TQ).研究表明,3种聚合物都有较窄的带隙(P1:1.23 e V,P2:1.51 e V,P3:1.50 e V),有利于活性层材料对太阳光的吸收,其中P1获得了最宽的吸收(近1000 nm).将P1~P3与PC71BM共混制备光伏器件,当给受体比例为1∶3时,基于P1的光伏器件短路电流密度(short-circuit current density,JSC)为15.82 m A/cm^2,开路电压(open-circuit voltage,VOC)为0.38 V,能量转化效率(power conversion efficiency,PCE)达到3.33%,为3种聚合物中最高的效率.对于聚合物P2和P3,在给受体比例为1∶2时,光伏性能最好,此时P2与P3的PCE值分别为1.20%和1.37%,导致较低光电转换效率的因素是短路电流密度JSC(P2:9.70 m A/cm^2,P3:9.21 m A/cm^2)和开路电压VOC(约0.3 V)过低.In the polymer solar cells research field, dithieno[3,2-b：2＇,3＇-d]pyrrole （DTP） is a good donor unit due to its good planarity when it is used as build donor-acceptor （D-A） polymer. In this work, three DTP based polymers （named P1, P2, P3） are synthesized by polymerizing DTP with DPP, DTBO and TQ co-monomer acceptor unit, respectively. These three polymers exhibit good solubility in common solvent such as dichlorobenzene. GPC results show that the polymers show moderate number-average molecular weights （Mn, 9 - 103 to 2.2 - 104） and narrow PDI （1 - 2）. UV-Vis absorption spectra in solution and thin film show that the polymers have a relatively narrow band gap （PI： 1.23 eV, P2： 1.51 eV; P3：1.50 eV）, which enhances the polymer absorption of sunlight, with P1 showing the widest absorption （extending UV-Vis absorption to nearly 1000 nm）. The thermal property of these polymers is measured by thermogravimetric analysis （TGA）, giving their Ta located at 313 - 410 ℃. The highest occupied molecular orbital （HOMO） energy levels of the polymers are between -5.2 eV and -5.4 eV, as tested by CV method. Photovoltaic devices are fabricated with P1 - P3 as donor and PCT1BM as acceptor in active layer. The solar cells J-V test results reveal that P1 has the highest PCE of 3.33% with Jscof 15.82 mA/cm2, Vocof 0.38 V when the mass ratio of P1 to PCT^BM is kept at 1：3. The relative high PCE of P1 based PSCs devices is due to the wide light absorption, leading to high Jsc of PSCs devices, which also can be confirmed by external quatum efficiency （EQE） test. For the polymers P2 and P3, with the mass ratio of polymer/PC7IBM at 1：2, PCE of 1.20% for P2 and 1.37% of P3 are achieved respectively, and the relatively low PCE is caused by low short circuit current density （dsc） （P2：9.70 mA/cm2, P3：9.21 mA/cm2） and the low open-circuit voltage （Voc, only around 0.3 V）. Transmission electron microscopy is also used to explore the polymer solar cells active layer morpholo

关 键 词：二噻吩[3 2-b′ 3′-d]并吡咯 共轭聚合物 光伏材料 聚合物太阳能电池 

分 类 号：TM914.4[电气工程—电力电子与电力传动]