双烷硫基噻吩侧链光伏材料与器件研究  

Study on Photovoltaic Materials and Devices of Dis(alkylthio)thiophene Side Chains

作　　者：石芙蓉 陈斌 郭鹏智 SHI Fu-rong;CHEN Bin;GUO Peng-zhi(Key Laboratory of Opto Technology and Inelligent Control of Ministy of Education,Lanzhou Jaotong University,Lanzhou 730070,China;National Green Coating Technology and Equipment Research Center,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]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 [2]兰州交通大学国家绿色镀膜技术与装备工程技术研究中心,兰州730070

出　　处：《兰州交通大学学报》2023年第2期144-155,共12页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金青年基金(51903112)。

摘　　要：通过将硫原子引入到共轭聚合物的侧链中,不仅可以降低共轭聚合物的最高占据分子轨道(HOMO)能级,而且可以提高共轭聚合物的介电常数。二噻并[2,3-d∶2′,3′-d′]苯并[1,2-b∶4,5-b′]二噻吩(DTBDT)相对于[1,2-b∶4,5-b′]苯并二噻吩(BDT)有更大的共轭面,更长的共轭长度,有利于载流子的传输。在DTBDT的5,10位引入噻吩双烷硫基侧链,分别与受体单元[2,1,3]苯并噻二唑和氟代的[2,1,3]苯并噻二唑通过Stille偶联合成共轭聚合物PDTBDT-DST-BT和PDTBDT-DST-FBT。共轭聚合物PDTBDT-DST-BT和PDTBDT-DST-FBT在350~700 nm范围内有强的吸收系数,并且两种共轭聚合物有低的HOMO能级(-5.51 eV和-5.56 eV)和较高的介电常数,基于双烷硫基的引入,在1 kHz时共轭聚合物的介电常数从4.1增加到了5.2。将PDTBDT-DST-BT和PDTBDT-DST-FBT作为给体材料与富勒烯受体PC71BM制备有机聚合物太阳能电池(OSCs)器件,结果表明,共轭聚合物侧链中硫原子的引入,对光伏器件的开路电压(VOC)和填充因子FF有明显地提高,从而得到了5.05%的能量转换效率。Introducing sulfur atoms into the side chains of the conjugated polymerscannot only reduce the highest occupied molecular orbital(HOMO)energy levels of the conjugated polymers,but also increase the dielectric constant of the conjugated polymers.Dithieno[2,3-d:2′,3′-d′]-benzo[1,2b:4,5-b′]dithiopheneholds a larger coplanar core and an extended conjugation length than[1,2-b:4,5-b′]benzodithiophene(BDT),which can facilitate carrier transport.In this paper,bis(4,5-bis(decylthio)thienyls as the side chains were introduced at 5,10-positions of DTBDT to obtain the intermediate DTBDT-DTS,and the conjugated polymers PDTBDT-DST-BT and PDTBDT-DST-FBT were synthesized by Stille coupling reaction between DTBDT-DTS with the acceptor unit[2,1,3]benzothiadiazole and fluorinated[2,1,3]benzothiadiazole,respectively.The conjugated polymers PDTBDT-DST-BT and PDTBDT-DSTFBT exhibited extensive light absorption in the range of 350~700 nm,lower HOMO energy levels(-5.56 eV and-5.51 eV)and higher dielectric constants,and the dielectric constants of the conjugated polymers increased from4.1 to 5.2 at 1 kHz with the introduction of bis(alkylthio)groups.Organic polymer solar cells(PSCs)devices were prepared by using PDTBDT-DST-BT and PDTBDT-DST-FBT as donor materials paired with fullerene acceptor PC_(71)BM,the results showed that the introduction of sulfur atoms in the side chains of the conjugated polymers significantly improved the open circuit voltage(V_(oc))and fill factor of the photovoltaic devices,resulting in an energy conversion efficiency of 5.05%.

关 键 词：双烷硫基噻吩侧基 二噻并[2 3-d∶2′ 3′-d′]苯并[1 2-b∶4 5-b′]二噻吩 介电常数 苯并噻二唑 

分 类 号：TB43[一般工业技术] TB34