Hole transport materials (HTMs) play a pivotal role in the hole extraction and transportation processes in perovskite solar cells (PSCs). Although a great number of HTMs based on various planar conjugated cores have been explored, the development of branches is rather limited. In this work, branches of 9-phenyl-9H-carbazole derivatives have been incorporated in different N-alkylated dithieno[3,2-b:2′,3′-d]pyrrol (DTP) core to construct HTMs (TM-9 to TM-14). Among them, TM-13 with 9-(4-methoxyphenyl)-9H-carbazole branch exhibites excellent performance in hole extraction and transportation ability. Consequently, the PSCs based on TM-13 have achieved the power conversion efficiency (PCE) of 20.44%, which is comparable to the PCE of 20.62% with the widely used Spiro-OMeTAD HTM. More importantly, the synthetic cost of TM-13 (62 $/g) is much lower than that of Spiro-OMeTAD (400 $/g), suggesting its promising commercialization for low-cost and efficient HTMs for PSCs.

空穴传输材料 (HTM) 在钙钛矿太阳能电池 (PSC) 的空穴提取和传输过程中起着关键作用。尽管已经探索了大量基于各种平面共轭核的 HTM，但分支的发展相当有限。在这项工作中，9-苯基-9H-咔唑衍生物的分支已被掺入不同的N-烷基化二噻吩并[3,2-b:2',3'-d]吡咯（DTP）核心以构建HTMs（TM-9到TM-14）。其中，具有9-(4-甲氧基苯基)-9H-咔唑支链的TM-13在空穴提取和传输能力方面表现出优异的性能。因此，基于TM-13的 PSC实现了功率转换效率（PCE) 的 20.44%，与广泛使用的 Spiro-OMeTAD HTM的PCE的 20.62% 相当。更重要的是，TM-13的合成成本（62 美元/克）远低于 Spiro-OMeTAD（400 美元/克），表明其在 PSC 的低成本和高效 HTM 的商业化方面很有前景。