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Highlights: A mixed GAI and MAI (MGM) treatment modulating the bulk and interfacial defects simultaneously is reported. The devices' performance is enhanced to ~24.5% in 0.12 cm2 and ~18.7% in 64 cm2 with improved stability. The MGM treatment can be applied to a wide range of perovskite compositions. Here, we report a mixed GAI and MAI (MGM) treatment method by forming a 2D alternating-cation-interlayer (ACI) phase (n = 2) perovskite layer on the 3D perovskite, modulating the bulk and interfacial defects in the perovskite films simultaneously, leading to the suppressed nonradiative recombination, longer lifetime, higher mobility, and reduced trap density. Consequently, the devices' performance is enhanced to 24.5% and 18.7% for 0.12 and 64 cm2, respectively. In addition, the MGM treatment can be applied to a wide range of perovskite compositions, including MA-, FA-, MAFA-, and CsFAMA-based lead halide perovskites, making it a general method for preparing efficient perovskite solar cells. Without encapsulation, the treated devices show improved stabilities. [ABSTRACT FROM AUTHOR]

CHNHPbI perovskite solar cells with 2TPA- n-DP (TPA = 4,4′-((1E, 1′E,3E,3′E)-[1,1′-biphenyl]-4,4′-diylbis(buta-1,3-diene-4,1-diyl)); DP = bis( N, N-di-p-tolylaniline); n = 1, 2, 3, 4) as hole-transporting materials (HTMs) have been fabricated. After optimization of the mesoporous TiO film thickness, devices based on 2TPA-2-DP with power conversion efficiencies (PCEs) of up to 12.96% have been achieved, comparable to those of devices with (2,2′,7,7′-tetrakis( N, N-di-p-methoxyphenylamine)-9,9′-spirobifluorene) (spiro-OMeTAD) as HTM under similar conditions. Further time-resolved photoluminescence (PL) measurements showed a fast charge transfer process at the perovskite/2TPA-2-DP interface. With the aid of electrochemical impedance spectra, a study of the electron blocking ability of 2TPA-2-DP in the device reveals that the presence of 2TPA-2-DP can greatly increase charge transfer resistance at the HTM/Au interface in the device, thus reducing the recombination. Furthermore, the perovskite solar cells based on these four HTMs exhibit good stability after testing for one month. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]