A series of D-A1-D-A2 random polymers PTPDBTO-T, PTPDBTO-TT and PTPDBTO-3T, based on three different electron-donor units (D) (thiophene (T), thieno[3,2-b]thiophene (TT) and terthiophene (3T)) and two electron-accept units (A1 and A2) were synthesized and characterized for thickness insensitive polymer solar cells (PSCs). Three D units (T, TT and 3T) had a remarkable effect on the optical physics properties, solution process ability, and charge carrier transport of the resultant polymers, which in turn influenced their photovoltaic performances. It was observed that the absorption coefficient of PTPDBTO-TT was higher than that of PTPDBTO-T or PTPDBTO-3T. As a result, the random polymer PTPDBTO-TT based PSCs obtained power conversion efficiency (PCE) of 6.92% and fill factor (FF) of 61% at a thick active layer of 285 nm. The devices based on PTPDBTO-T afforded PCE of 6.37% and FF of 62% with an active layer thickness of 183 nm. Moreover, the photovoltaic performance of PSCs based on PTPDBTO-T and PTPDBTO-TT was insensitive to active layer thickness. Specifically, their PCEs were basically over 6% and FFs over 60% when the active layer thicknesses were tuned within 100–280 nm.

基于三个不同的电子给体单元（D）（噻吩（T），噻吩并[3,2- b]的一系列D-A1-D-A2无规聚合物PTPDBTO-T，PTPDBTO-TT和PTPDBTO-3T合成了噻吩（TT）和叔噻吩（3T）以及两个电子接受单元（A1和A2），并对厚度不敏感的聚合物太阳能电池（PSC）进行了表征。三个D单元（T，TT和3T）对所得聚合物的光学物理性质，固溶处理能力和电荷载流子传输有显着影响，进而影响了它们的光伏性能。观察到PTPDBTO-TT的吸收系数高于PTPDBTO-T或PTPDBTO-3T的吸收系数。结果，基于无规聚合物PTPPDBO-TT的PSC在285nm厚的有源层上获得了6.92％的功率转换效率（PCE）和61％的填充因子（FF）。基于PTPDBTO-T的器件提供了6.37％的PCE和6％的FF，有效层厚度为183 nm。而且，基于PTPDBTO-T和PTPDBTO-TT的PSC的光伏性能对有源层厚度不敏感。具体来说，当在100-280 nm范围内调整有源层厚度时，它们的PCE基本上超过6％，而FF超过60％。