The solution‐processed layer‐by‐layer (LBL) method has potential to achieve high‐performance polymer solar cells (PSCs) due to its advantage of enriching donors near the anode and acceptors near the cathode. However, power conversion efficiencies (PCEs) of the LBL‐PSCs are still significantly lower than those of conventional one‐step‐processed PSCs (OS‐PSCs). A method to solve the critical problems in LBL‐PSCs is reported here. By employing a specific mixed solvent (o‐dichlorobenzene [o‐DCB]/tetrahydrofuran) to spin‐coat the small‐molecular acceptor IT‐4F onto a layer of the newly designed polymer donor (PBDB‐TFS1), appropriate interdiffusion between the PBDB‐TFS1 and the IT‐4F can critically be controlled, and then an ideal phase separation of the active layer and large donor/acceptor interface area can be realized with a certain amount of o‐DCB. The PSCs based on the LBL method exhibit PCEs as high as 13.0%, higher than that of the counterpart (11.8%) made by the conventional OS solution method. This preliminary work reveals that the LBL method is a promising approach to the promotion of the photovoltaic performance of polymer solar cells.

中文翻译：

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迈向通过溶液处理逐层方法处理的高效聚合物太阳能电池

由于溶液富集阳极附近的施主和阴极附近的受主，其溶液处理的逐层（LBL）方法具有实现高性能聚合物太阳能电池（PSC）的潜力。但是，LBL-PSC的功率转换效率（PCE）仍远低于传统的一步处理PSC（OS-PSC）。本文介绍了一种解决LBL-PSC中关键问题的方法。通过使用特定的混合溶剂（邻二氯苯[ o-DCB] /四氢呋喃）将小分子受体IT-4F旋涂到新设计的聚合物供体（PBDB-TFS1）的一层上，可以严格控制PBDB-TFS1和IT-4F之间的适当扩散，然后通过一定量的o- DCB可以实现有源层和较大的供体/受体界面面积的理想相分离。基于LBL方法的PSC的PCE高达13.0％，高于通过常规OS解决方案方法制造的PCE（11.8％）。这项初步工作表明，LBL方法是提高聚合物太阳能电池光伏性能的一种有前途的方法。