Evaluating the influence of heteroatoms on the electronic properties of aryl[3,4-c]pyrroledione based copolymers
作者:Benjamin J. Hale、Moneim Elshobaki、Ryan Gebhardt、David Wheeler、Jon Stoffer、Aimée Tomlinson、Sumit Chaudhary、Malika Jeffries-EL
DOI:10.1016/j.polymer.2016.12.013
日期:2017.1
A donor-acceptor-type conjugated copolymer (PBDT-PPD) composed of benzodithiophene (BDT) and pyrrolopyrroledione (PPD) was synthesized using the Stille cross-coupling reaction. Using both experimental and theoretical data, the optical, electrochemical, and photovoltaic properties of PBDT-PPD were compared with those of its sulfur analog, PBDT-TPD, which is composed of BDT and thienopyrroledione (TPD)
使用Stille交叉偶联反应合成由苯并二噻吩(BDT)和吡咯并吡咯二酮(PPD)组成的供体-受体型共轭共聚物(PBDT-PPD)。使用实验和理论数据,将PBDT-PPD的光学,电化学和光电性能与由BDT和噻吩并吡咯二酮(TPD)组成的硫类似物PBDT-TPD进行了比较。测得聚合物的光学带隙分别为1.86和2.20eV。虽然两种材料都具有相似的最高占用分子轨道(HOMO)水平,但相对于PBDT-TPD,PBDT-PPD的最低未占用分子轨道(LUMO)水平有所提高。结合了PBDT-PPD的器件具有更高的开路电压和填充因子,但短路电流密度却大大降低(Jsc)高于PBDT-TPD,从而导致较低的功率转换效率(PCE)。缺乏明显的分子内电荷转移(ICT)以及PBDT-PPD的高LUMO导致与太阳光谱的光谱重叠差,从而降低了J sc。另外,向PCBM注入的电子很差,这也降低了PCE。