Bin Haijun, Datta Kunal, Wang Junke, van der Pol Tom P A, Li Junyu, Wienk Martijn M, Janssen René A J
Molecular Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands.
Dutch Institute for Fundamental Energy Research, Eindhoven 5612 AJ, The Netherlands.
ACS Appl Mater Interfaces. 2022 Apr 13;14(14):16497-16504. doi: 10.1021/acsami.2c01900. Epub 2022 Mar 30.
Interface layers used for electron transport (ETL) and hole transport (HTL) often significantly enhance the performance of organic solar cells (OSCs). Surprisingly, interface engineering for hole extraction has received little attention thus far. By finetuning the chemical structure of carbazole-based self-assembled monolayers with phosphonic acid anchoring groups, varying the length of the alkane linker (2PACz, 3PACz, and 4PACz), these HTLs were found to perform favorably in OSCs. Compared to archetypal PEDOT:PSS, the PACz monolayers exhibit higher optical transmittance and lower resistance and deliver a higher short-circuit current density and fill factor. Power conversion efficiencies of 17.4% have been obtained with PM6:BTP-eC9 as the active layer, which was distinctively higher than the 16.2% obtained with PEDOT:PSS. Of the three PACz derivatives, the new 3PACz consistently outperforms the other two monolayer HTLs in OSCs with different state-of-the-art nonfullerene acceptors. Considering its facile synthesis, convenient processing, and improved performance, we consider that 3PACz is a promising interface layer for widespread use in OSCs.
用于电子传输（ETL）和空穴传输（HTL）的界面层通常能显著提高有机太阳能电池（OSC）的性能。令人惊讶的是，迄今为止，用于空穴提取的界面工程很少受到关注。通过微调带有膦酸锚定基团的咔唑基自组装单分子层的化学结构，改变烷烃连接链的长度（2PACz、3PACz和4PACz），发现这些HTL在OSC中表现良好。与典型的PEDOT:PSS相比，PACz单分子层具有更高的光学透过率和更低的电阻，并能提供更高的短路电流密度和填充因子。以PM6:BTP-eC9作为活性层时，功率转换效率达到了17.4%，明显高于使用PEDOT:PSS时获得的16.2%。在这三种PACz衍生物中，新型的3PACz在与不同的最先进非富勒烯受体的OSC中始终优于其他两种单分子层HTL。考虑到其合成简便、加工方便且性能有所提高，我们认为3PACz是一种有前途的界面层，有望在OSC中广泛应用。
