Wang, JialinLu, HaizhouLIu, YuhangWang, PengyangWang, SanlongDong, XiyueZhao, YingLiu, YongshengGratzel, MichaelZhang, Xiaodan2025-01-282025-01-282025-01-272024-12-1110.1021/acsenergylett.4c0250710.1021/acsenergylett.5c01036https://infoscience.epfl.ch/handle/20.500.14299/245832WOS:001376037600001Spiro-OMeTAD has served as a crucial hole transporting material (HTM) in the advancement of efficient perovskite solar cells (PSCs). However, the diminished thermal stability of lithium-doped Spiro-OMeTAD (Li-Spiro) has been a limiting factor, leading to a significant decline of the power conversion efficiency (PCE) and stability, particularly at a temperature exceeding 65 degrees C. Here, we report an upgraded HTM, Spiro-OMeCzCl, by incorporating chloroethyl-modified carbazole units to expand the conjugated area of the donor group. This novel configuration significantly enhances the thermal stability and film quality. The resulting PSCs utilizing Spiro-OMeCzCl achieved a high PCE of 24.6%, coupled with exceptional long-term stability. The target cells maintained approximately 95% of their initial PCE after 57 days under a nitrogen atmosphere. Importantly, in subsequent thermal stability tests involving a gradual temperature increase, the cells sustained an average PCE of over 85% after 200 h at temperatures ranging from 60 to 90 degrees C.EnglishHOLE-TRANSPORT MATERIALLOW-COSTEFFICIENTVOLTAGEScience & TechnologyPhysical SciencesTechnologytext::journal::journal article::research article