The relatively large voltage loss (V_loss) in excitonic type solar cells severely limits their power conversion efficiencies (PCEs). Here, we report a comprehensive control of V_loss through efficacious engineering of the sensitizer and redox mediator, making a breakthrough in the PCE of dye-sensitized solar cells (DSSCs). The targeted down-regulation of V_loss is successfully realized by three valid channels: (i) reducing the driving force of electron injection through dye molecular engineering, (ii) decreasing the dye regeneration overpotential through redox mediator engineering, and (iii) suppressing interfacial electron recombination. Significantly, the “trade-off” effect between the dye optical band gap and the open-circuit voltage (V_OC) is minimized to a great extent, achieving a distinct enhancement in photovoltaic performance (PCE > 11.5% with V_OC up to 1.1 V) for liquid junction cells. The solidification of the best-performing device leads to a PCE of 11.7%, which is so far the highest efficiency obtained for solid-state DSSCs. Our work inspires further development in highly efficient excitonic solar cells by comprehensive control of V_loss.

中文翻译：

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电压损失的全面控制可实现11.7％的高效固态染料敏化太阳能电池†

激子型太阳能电池中相对较大的电压损耗（V _loss）严重限制了其功率转换效率（PCE）。在这里，我们报告了通过敏化剂和氧化还原介体的有效工程来全面控制V_{损失的方法}，从而在染料敏化太阳能电池（DSSC）的PCE中取得了突破。有针对性地下调V_损耗通过三个有效途径成功实现了这一目标：（i）通过染料分子工程降低电子注入的驱动力；（ii）通过氧化还原介体工程降低染料再生的超电势；以及（iii）抑制界面电子复合。显着地，染料光学带隙和开路电压（V _OC）之间的“折衷”效应被极大地减小了，从而实现了光伏性能的显着提高（V _OC时PCE> 11.5％）液体结电池的最大电压为1.1 V）。最佳性能设备的固化导致PCE为11.7％，这是迄今为止固态DSSC所获得的最高效率。通过全面控制V_损耗，我们的工作激发了高效激子太阳能电池的进一步开发。