化学学报 ›› 2015, Vol. 73 ›› Issue (10): 1055-1060.DOI: 10.6023/A15040282 上一篇    下一篇

研究论文

新型噻咯共轭聚合物的合成及其光伏性能

李昱达a, 张恒c, 王迅昶a, 汪锋a,b, 夏养君c   

  1. a 武汉工程大学 绿色化工过程教育部重点实验室 武汉 430073;
    b 华南理工大学 发光材料与器件国家重点实验室 广州 510640;
    c 兰州交通大学 光电技术与智能控制教育部重点实验室 兰州 730070
  • 投稿日期:2015-04-26 发布日期:2015-07-17
  • 通讯作者: 夏养君 E-mail:psfwang@wit.edu.cn, yjxia73@126.com
  • 基金资助:

    项目受国家自然科学基金(No.51103111)、教育部新世纪优秀人才支持计划(No.NCET-12-0714)、发光材料与器件国家重点实验室开发基金(No.2014-skllmd-11)、教育部留学人员科研启动基金资助.

Synthesis and Photovoltaic Properties of Silole-Containing Conjugated Polymers

Li Yudaa, Zhang Hengc, Wang Xunchanga, Wang Fenga,b, Xia Yangjunc   

  1. a Key Laboratory for Green Chemical Engineering and Process of Ministry of Education, Wuhan Institute of Technology, Wuhan 430073;
    b State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640;
    c Key Laboratory of Opto-Technology and Intelligent Control of Ministry of Education, Lanzhou Jiaotong University, Lanzhou 730070
  • Received:2015-04-26 Published:2015-07-17
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 51103111), the Education Ministry of China (No. NCET-12-0714), the Open Fund of the State Key Laboratory of Luminescent Materials and Devices (No. 2014-skllmd-11) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars.

噻咯(silole)是一类含硅的五元环二烯, 具有很好的电子亲和力、独特的聚集态诱导发光性质和优良的电致发光性能. 研究者发现将噻咯结构单元引入分子主链中, 能够获得具有特殊光电性能的聚合物材料. 本工作合成两种2,5位为二噻吩苯并噻二唑的新型噻咯单体, 通过与芴或硅芴双硼酸酯Suzuki偶联聚合, 制备四种主链型D-A(推-拉电子结构)共聚物PF-HSTBT, PF-HOSTBT, PSiF-HSTBT和PSiF-HOSTBT. 研究表明, 四种聚合物具有较好的吸收, 光学带隙均小于1.71 eV. 电化学分析测得四种聚合物的HOMO能级均小于-5.29 eV, 通过光学带隙计算得LUMO能级均高于-3.61 eV. 以四种聚合物分别作为电子给体材料, PC61BM为受体材料, 制备了聚合物太阳能电池器件(PSCs). 由于聚合物PF-HOSTBT、PSiF-HOSTBT中的己氧基空间位阻较大, 分子平面规整性较差, 其最高光电转换效率分别为0.62%、0.83%; 而己基的空间位阻较小, 分子堆积紧密, 聚合物PF-HSTBT, PSiF-HSTBT的光伏性能较优, PSCs的最高光电转换效率分别为1.18%, 1.2%.

关键词: 噻咯, 芴, 硅芴, 给体, 聚合物太阳能电池

Siloles are a group of five-membered silacyclics that possess a unique low-lying LUMO level associated with s*-p* conjugation. Siloles exhibit high electron acceptability, unusual aggregation-induced emission (AIE) and have been utilized as light-emitting layers in the fabrication of electroluminescence devices. The incorporation of 2,3,4,5-tetraarylsiloles into the main chain of polymers is of interest and importance in chemistry and functionalities. Some optoelectronic properties, impossible for silole small molecules, may be realized with silole-containing polymers. In this paper, four donor-acceptor (D-A) conjugated polymers with electron-withdrawing silole units and electron-donating fluorene or silafluorene units have been synthesized and characterized by NMR, TGA, GPC, and elemental analysis measurement. The photophysical properties show that all the polymers exhibit broad absorption range covering the whole UV-vis spectral region of the sunlight. The HOMO energy levels of four polymers are lower than -5.2 eV and the LUMO energy levels of them are higher than -3.6 eV, so these polymers are promising candidates for the effective applications of polymer solar cells (PSCs). Therefore, the photovoltaic properties of the polymer as donor was investigated by fabricating the bulk-heterojunction (BHJ) solar cells with a typical structure of ITO/PEDOT:PSS/polymer:PC61BM/Al. As a preliminary result, the BHJ devices based on PF-HSTBT, PF-HOSTBT, PSiF-HSTBT, and PSiF-HOSTBT showed the power conversion efficiencies (PCEs) of 1.18%, 0.62%, 1.2%, and 0.83%, respectively. The short-circuit current density (Jsc) and PCE values of PSCs based on PF-HSTBT and PSiF-HSTBT are higher than those of PF-HOSTBT and PSiF-HOSTBT because of the reduced steric hindrance and improved structural planarity.

Key words: siloles, fluorene, silafluorene, donor, polymer solar cells