Three new thieno[3,2‐b][1]benzothiophene (TBT)‐based donor–π–acceptor (D–π–A) sensitizers, coded as SGT‐121, SGT‐129, and SGT‐130, have been designed and synthesized for dye‐sensitized solar cells (DSSCs), for the first time. The TBT, prepared by fusing thiophene unit with the phenyl unit of triphenylamine donor, is utilized as the π‐bridge for all sensitizers with good planarity. They have been molecularly engineered to regulate the highest occupied molecular orbital (HOMO)‐lowest unoccupied molecular orbital (LUMO) energy levels and extend absorption range as well as to control the electron‐transfer process that can ensure efficient dye regeneration and prevent undesired electron recombination. The photovoltaic performance of SGT‐sensitizer‐based DSSCs employing Co(bpy)₃^2+/3+ (bpy = 2,2′‐bipyridine) redox couple is systematically evaluated in a thorough comparison with Y123 as a reference sensitizer. Among them, SGT‐130 with benzothiadiazole‐phenyl (BTD‐P) unit as an auxiliary acceptor exhibits the highest power‐conversion efficiency (PCE) of 10.47% with J_sc = 16.77 mA cm⁻², V_oc = 851 mV, and FF = 73.34%, whose PCE is much higher than that of Y123 (9.5%). It is demonstrated that the molecular combination of each fragment in D–π–A organic sensitizers can be a pivotal factor for achieving the higher PCEs and an innovative strategy for strengthening the drawbacks of the π‐bridge.

中文翻译：

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Thieno [3,2–b] [1]苯并噻吩衍生物作为D–π–A结构有机增敏剂中的新型π桥单元，对染料敏化太阳能电池的效率超过10.47％

三种基于硫代噻吩[3,2- b ] [1]苯并噻吩（TBT）的供体-π-受体（D-π-A）敏化剂已被编码为SGT - 121，SGT - 129和SGT - 130。首次为染料敏化太阳能电池（DSSC）设计和合成。该TBT通过将噻吩单元与三苯胺供体的苯基单元融合而制备的，被用作具有良好平面性的所有敏化剂的π桥。它们经过分子工程设计，可调节最高占据分子轨道（HOMO）-最低未占据分子轨道（LUMO）的能级并扩展吸收范围，并控制电子转移过程，从而确保有效的染料再生并防止不良的电子重组。系统评估了使用Co（bpy）₃ ^{2 + / 3 +}（bpy = 2,2'-联吡啶）氧化还原对的SGT增敏剂基DSSC的光伏性能，并与作为参考增敏剂的Y123进行了全面比较。其中，SGT - 130以苯并噻二唑-苯基（BTD - P）单元作为辅助受体时，J _sc = 16.77 mA cm ^-2，V _oc = 851 mV和FF = 73.34％时，其功率转换效率（PCE）最高，为10.47％PCE远高于Y123（9.5％）。结果表明，D–π–A有机敏化剂中每个片段的分子结合可能是获得更高PCE的关键因素，也是增强π-桥缺点的创新策略。