A new series of PM6-based terpolymers (PM10Si, PM20Si, and PM30Si) containing 10%, 20% and 30% DTBT (4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole) with siloxane-terminated side chains were designed and synthesized. These terpolymers were used as donor materials with the acceptor Y6 to fabricate polymer solar cells (PSCs), where both the routine blend casting method and the two-step sequential deposition (SD) method were applied to investigate the photovoltaic properties of these terpolymers. The inverted device based on PM20Si with 20% siloxane-terminated side chains on the DTBT unit exhibited better power conversion efficiencies (PCEs) of 14.30% due to having a more suitable phase state and more prominent face-on orientations. With further optimization by the SD method, the device based on PM20Si obtained an excellent efficiency of 15.17% with a short-current density (J_sc) of 26.92 mA cm⁻², and a fill factor (FF) of 70.44%, which could be put down to its more balanced charge mobility (μ_h/μ_e = 1.10). This work demonstrates that controlling the content of DTBT with siloxane-terminated side chains in the terpolymers can supply a positive driving force for phase separation and molecular packing of the active layer, which provides a novel way to improve the photovoltaic performance.

中文翻译：

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含苯并噻二唑并带有硅氧烷封端的侧链的PM6基三元共聚物供体的光电性能得到改善

含有10％，20％和30％DTBT（4,7-二（噻吩-2-基）苯并[ c]的PM6基三元共聚物的新系列（PM10Si，PM20Si和PM30Si）设计并合成了具有硅氧烷末端侧链的[[1,2,5]噻二唑）。这些三元共聚物与受体Y6一起用作供体材料，以制造聚合物太阳能电池（PSC），其中常规的混合浇铸方法和两步顺序沉积（SD）方法均用于研究这些三元共聚物的光伏性能。基于PM20Si的倒置器件在DTBT单元上具有20％的硅氧烷封端的侧链，由于具有更合适的相态和更显着的面朝取向，因此具有14.30％的更好的功率转换效率（PCE）。通过SD方法的进一步优化，基于PM20Si的器件获得了15.17％的出色效率，短路电流密度（J _sc）为26.92 mA cm ^-2和填充因子的70.44％（FF），这可能是归因于它的更平衡的电荷迁移率（μ _ħ / μ _ë = 1.10）。这项工作表明，控制三元共聚物中带有硅氧烷末端侧链的DTBT的含量可以为活性层的相分离和分子堆积提供正驱动力，这为改善光伏性能提供了一种新颖的方法。