Liu, XuepengDing, BinHan, MingyuanYang, ZhenhaiChen, JianlinShi, PengjuXue, XiangyingGhadari, RahimZhang, XianfuWang, RuiBrooks, KeithTao, LiKinge, SachinDai, SongyuanSheng, JiangDyson, Paul J.Nazeeruddin, Mohammad KhajaDing, Yong2023-07-032023-07-032023-07-032023-06-0710.1002/anie.202304350https://infoscience.epfl.ch/handle/20.500.14299/198765WOS:001003980300001Hole transport materials (HTMs) are a key component of perovskite solar cells (PSCs). The small molecular 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl)-amine-9,9'-spirobifluorene (spiro-OMeTAD, termed "Spiro") is the most successful HTM used in PSCs, but its versatility is imperfect. To improve its performance, we developed a novel spiro-type HTM (termed "DP") by substituting four anisole units on Spiro with 4-methoxybiphenyl moieties. By extending the p-conjugation of Spiro in this way, the HOMO level of the HTM matches well with the perovskite valence band, enhancing hole mobility and increasing the glass transition temperature. DP-based PSC achieves high power conversion efficiencies (PCEs) of 25.24 % for small-area (0.06 cm(2)) devices and 21.86 % for modules (designated area of 27.56 cm(2)), along with the certified efficiency of 21.78 % on a designated area of 27.86 cm(2). The encapsulated DP-based devices maintain 95.1 % of the initial performance under ISOS-L-1 conditions after 2560 hours and 87 % at the ISOS-L-3 conditions over 600 hours.Chemistry, MultidisciplinaryChemistryhole transport materialsmodulesperovskite solar cellspi-conjugated systemstabilityhighly efficientfill factorscellstext::journal::journal article::research article