The Nb₂CT_x nanoflakes as members of the MXene family have attracted a lot of attention because of their unique optoelectronic properties. In this work, we use alkali and annealing treatments to regulate the surface functional groups in Nb₂CT_x and then adjust its work function (WF). After KOH treatment, the −F group is replaced by an −OH group, leading to a decrease in WF from 4.62 eV (Nb₂CO_1.2OH_0.6F_0.2) to 4.32 eV (Nb₂CO_1.2OH_0.8). After annealing, −OH is transformed into −O, resulting in a WF increase to 5.03 eV (Nb₂CO_1.36OH_0.2). Polymer solar cells (PSCs) based on PM6:BTP-eC9:PC₇₁BM with tuned Nb₂CT_x as the electron transport layer (ETL) and the hole transport layer (HTL) exhibit the highest power conversion efficiency (PCE) of 17.64% and 17.51%, respectively. These efficiencies are comparable to those gained using conventional charge transport layers. This work provides a good method to tune the WF of Nb₂CT_x and exhibits the Nb₂CT_x nanoflakes have a great application prospect in PSCs.

中文翻译：

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通过控制表面官能团调节 Nb2CTx 纳米薄片作为有机太阳能电池中的空穴和电子传输层的功函数

Nb ₂ CT _x纳米薄片作为 MXene 家族的一员，因其独特的光电特性而备受关注。在这项工作中，我们使用碱和退火处理来调节 Nb ₂ CT _{x 中}的表面官能团，然后调整其功函数（WF）。KOH处理后，-F基团被-OH基团取代，导致WF从4.62 eV（Nb ₂ CO _1.2 OH _0.6 F _0.2）降低到4.32 eV（Nb ₂ CO _1.2 OH _0.8）。退火后，-OH 转化为 -O，导致 WF 增加到 5.03 eV（Nb ₂ CO_1.36 OH _0.2 )。基于 PM6:BTP-eC9:PC ₇₁ BM 的聚合物太阳能电池 (PSC)，以调谐 Nb ₂ CT _x作为电子传输层 (ETL) 和空穴传输层 (HTL)，表现出最高的功率转换效率 (PCE)，为 17.64 % 和 17.51%，分别。这些效率与使用传统电荷传输层获得的效率相当。这项工作为调节Nb ₂ CT _x的WF 提供了一种很好的方法，并展示了Nb ₂ CT _x纳米薄片在PSCs 中具有很好的应用前景。