The notoriously poor stability of perovskite solar cells is a crucial issue restricting commercial applications. Here, a fluorinated perylenediimide (F‐PDI) is first introduced into perovskite film to enhance the device's photovoltaic performance, as well as thermal and moisture stability simultaneously. The conductive F‐PDI molecules filling at grain boundaries (GBs) and surface of perovskite film can passivate defects and promote charge transport through GBs due to the chelation between carbonyl of F‐PDI and noncoordinating lead. Furthermore, an effective multiple hydrophobic structure is formed to protect perovskite film from moisture erosion. As a result, the F‐PDI‐incorporated devices based on MAPbI3 and Cs0.05 (FA0.83MA0.17)0.95 Pb (Br0.17I0.83)3 absorber achieve champion efficiencies of 18.28% and 19.26%, respectively. Over 80% of the initial efficiency is maintained after exposure in air for 30 days with a relative humidity (RH) of 50%. In addition, the strong hydrogen bonding of F···H‐N can immobilize methylamine ion (MA+) and thus enhances the thermal stability of device, remaining nearly 70% of the initial value after thermal treatment (100 °C) for 24 h at 50% RH condition.

Tin‐based halide perovskites attract incremental attention due to the favorable optoelectronic properties and ideal bandgaps. However, the poor crystalline quality is still the biggest challenge for further progress in tin‐based perovskite solar cells (PVSCs) due to the unfavorable defects and uncontrollable crystallization kinetics. Here, acetic acid (HAc) is first introduced to reduce the supersaturated concentration of the precursor solution to preferentially form pre‐nucleation clusters, thus inducing rapid nucleation for effective regulation of crystallization kinetics. In particular, the hydrogen ion and acetate ion contained in HAc can effectively inhibit the oxidation of Sn2+, and the hydrogen bonding interaction between HAc and iodide ion (I‐) greatly reduces the loss of I‐, which guarantees the I‐/Sn2+ stoichiometric ratio of the corresponding perovskite film close to theoretical value, thus effectively reducing the defect density and maintaining the perfect crystal lattice. Consequently, the HAc‐assisted tin‐based PVSCs achieve a champion power conversion efficiency of 12.26% with superior open‐circuit voltage up to 0.75 V. Moreover, the unencapsulated device maintains nearly 90% of the initial PCE even after 3000 h storage in nitrogen atmosphere. This demonstrated strategy enables to prepare high‐quality tin‐based perovskite film with lower defect density and lattice distortion.

Sequential deposition is certified as an effective technology to obtain high‐performance perovskite solar cells (PVSCs), which can be derivatized into large‐scale industrial production. However, dense lead iodide (PbI2) causes incomplete reaction and unsatisfactory solution utilization of perovskite in planar PVSCs without mesoporous titanium dioxide as a support. Here, a novel autonomously longitudinal scaffold constructed by the interspersion of in situ self‐polymerized methyl methacrylate (sMMA) in PbI2 is introduced to fabricate efficient PVSCs with excellent flexural endurance and environmental adaptability. By this strategy perovskite solution can be confined within an organic scaffold with vertical crystal growth promoted, effectively inhibiting exciton accumulation and recombination at grain boundaries. Additionally, sMMA cross‐linked perovskite network can release mechanical stress and occupy the main channels for ion migration and water/oxygen permeation to significantly improve operational stability, which opens up a new strategy for the commercial development of large‐area PVSCs in flexible electronics.

High electronic quality perovskite films with a balanced charge transportation is critical for satisfying high‐performance for perovskite solar cells (PVSCs). However, the inferior band alignment of tin‐based perovskite films with an adjacent hole‐transport layer (HTL) leads to a poor hole transportation and collection. In this work, the semiconducting molecule poly[tetraphenylethene 3,3′‐(((2,2‐diphenylethene‐1,1‐diyl)bis(4,1‐phenylene))bis(oxy))bis(N,N‐dimethylpropan‐1‐amine)tetraphenylethene] (PTN‐Br) is introduced into a lead‐free perovskite precursor to form a bulk heterojunction film. In addition, the PTN‐Br molecule with the suitable highest occupied molecular orbital energy level (−5.41 eV) can fill into the grain boundaries of the perovskite film, serving as a hole‐transport medium between grains. The gradient band alignment of the perovskite film with poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HTL ensures excellent hole transportation and higher open‐circuit voltage. In addition, the π‐conjugated polymer PTN‐Br can passivate trap states within the perovskite film due to the formation of Lewis adducts between uncoordinated Sn atoms and the dimethylamino of PTN‐Br. Consequently, a champion efficiency of 7.94% is achieved with significant enhancements in the open‐circuit voltage and fill factor. Furthermore, the PTN‐Br incorporated device shows better ultra violet (UV) stability because of the UV barrier and passivating effect of PTN‐Br, retaining about 66% of its initial efficiency after 5 h of continuous UV light irradiation.

and modifying the charge transporting layers (CTLs), yet the interfacial mismatch between perovskite and CTLs is a non-negligible issue that dominates the efficiency and stability of corresponding devices. [7][8][9][10][11] Nickel oxide (NiO x ) nanocrystals as a promising stable hole transporting layer (HTL) in inverted p-i-n PVSCs are less prone to hysteresis and work well with flexible or tandem architectures. [12] Nevertheless, the PCE of NiO x -based inverted devices are usual inferior to the organic regular counterparts owing to the several interfacial issues: i) abundant surface traps and mismatch energy level restrict the charge carrier extraction, causing large energy offset; [13] ii) the redox reaction between Ni 3+ and A-site cation salts form a PbI 2 -rich hole extraction barrier, leading to severe interfacial destruction; [14] iii) inconsistent thermal expansion of lattice units in NiO x and perovskite results in tensile strain, prejudicing the microstructure and accelerating the degradation of perovskite. [15][16][17] Therefore, it is urge to solve these issues for performance enhancement and commercialization application of NiO x -based PVSCs.Recently, a great deal of molecular interlayers have been applied to passivate or adjust the energy level of NiO x /perovskite interface for strengthen the efficiency and stability in p-i-n devices, such as inorganic salts, [18][19][20] acids, [21] fullerene derivatives [22] and polymers buffer layer. [23][24][25] Nevertheless, most of the buffer layers are nonconductive and accompanied with the uncontrollable thickness and uniformity, which undoubtedly affect the optimization of charge transfer and perovskite crystal growth. Relatively speaking, the self-assembled small-molecule (SASM) can form thermodynamically favored ordered self-assembled layer that has been extensively proved as effective modifier to modulate the energy level and surface chemical state, as well as enhance the affinities of the deposition layer and substrate. [26] For instance, Fang et al. has reported that a polar chlorine-terminated SASM can modulate the energy-level alignment by forming a dipole moment at the interface. [27] Chen et al. has regulated the crystalline process and optimized the morphology of perovskite film by using 3-aminopropanioc acid SASM modified titanium oxide. [28] Other SASMs with different chemical terminations (such as amines, [29] carboxylates, [30] thiols, [31] and phosphonic acid [32] ) are also demonstrated to dramatically modify the electron Interfacial lattice mismatch and adverse reaction are the key issues hindering the development of nickel oxide (NiO x )-based inverted perovskite solar cells (PVSCs). Herein, a p-chlorobenzenesulfonic acid (CBSA) self-assembled small-molecule (SASM) is adopted to anchor NiO x and perovskite crystals to endow dual-passivation. The chlorine terminal of SASMs can provide growth sites for perovskite, leading to interfacial strain release. Meanwhile, the sulfonic acid group from SASMs can passivate surface defects of NiO x ,...