新型噻咯共轭聚合物的合成及其光伏性能  

Synthesis and Photovoltaic Properties of Silole-Containing Conjugated Polymers

作　　者：李昱达[1] 张恒[2] 王迅昶 汪锋[1,3] 夏养君[2] 

机构地区：[1]武汉工程大学绿色化工过程教育部重点实验室,武汉430073 [2]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 [3]华南理工大学发光材料与器件国家重点实验室,广州510640

出　　处：《化学学报》2015年第10期1055-1060,共6页Acta Chimica Sinica

基　　金：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);教育部留学人员科研启动基金资助;发光材料与器件国家重点实验室开发基金(No.2014-skllmd-11)~~

摘　　要：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,PSi F-HSTBT和PSi F-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 e V.电化学分析测得四种聚合物的HOMO能级均小于-5.29 e V,通过光学带隙计算得LUMO能级均高于-3.61 e V.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、PSi F-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,PSi F-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%.Siloles are a group of five-membered silacyclics that possess a unique low-lying LUMO level associated with σ＊-π＊ 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 photo-physical 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 ceils with a typical structure of ITO/PEDOT：PSS/polymer：PC61BM/A1. 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.

关 键 词：噻咯 芴 硅芴 给体 聚合物太阳能电池 

分 类 号：TQ317[化学工程—高聚物工业]