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In situ cyclized polyacrylonitrile (CPAN) is developed to replace n‐type metal oxide semiconductors (TiO2 or SnO2) as an electron selective layer (ESL) for highly efficient and stable n‐i‐p perovskite solar cells (PSCs). The CPAN layer is fabricated via facile in situ cyclization reaction of polyacrylonitrile (PAN) coated on a conducting glass substrate. The CPAN layer is robust and insoluble in common solvents, and possesses n‐type semiconductor properties with a high electron mobility of 4.13×10−3 cm2 V−1 s−1. With the CPAN as an ESL, the PSC affords a power conversion efficiency (PCE) of 23.12 %, which is the highest for the n‐i‐p PSCs with organic ESLs. Moreover, the device with the CPAN layer holds superior operational stability, maintaining over 90 % of their initial efficiency after 500 h continuous light soaking. These results confirm that the CPAN layer would be a desirable low‐cost and efficient ESL for n‐i‐p PSCs and other photoelectronic devices with high performance and stability. [ABSTRACT FROM AUTHOR]

Despite the remarkable progress made in perovskite solar cells, great concerns regarding potential Pb contamination risk and environmental vulnerability risks associated with perovskite solar cells pose a significant obstacle to their real-world commercialization. In this study, we took inspiration from the ensnaring prey behavior of spiders and chemical components in spider web to strategically implant a multifunctional mesoporous amino-grafted-carbon net into perovskite solar cells, creating a biomimetic cage traps that could effectively mitigate Pb leakage and shield the external invasion under extreme weather conditions. The synergistic Pb capturing mechanism in terms of chemical chelation and physical adsorption is in-depth explored. Additionally, the Pb contamination assessment of end-of-life perovskite solar cells in the real-world ecosystem, including Yellow River water and soil, is proposed. The sustainable closed-loop Pb management process is also successfully established involving four critical steps: Pb precipitation, Pb adsorption, Pb desorption, and Pb recycling. Our findings provide inspiring insights for promoting green and sustainable industrialization of perovskite solar cells. Potential lead contamination risk and environmental vulnerability risk impose a significant obstacle for the commercialization of perovskite solar cells. Here, the authors create a biomimetic cage traps to mitigate lead leakage and establish a sustainable closed-loop lead management process. [ABSTRACT FROM AUTHOR]

Low‐dimensional Ruddlesden‐Popper (LDRP) perovskites still suffer from inferior carrier transport properties. Here, we demonstrate that efficient exciton dissociation and charge transfer can be achieved in LDRP perovskite by introducing γ‐aminobutyric acid (GABA) as a spacer. The hydrogen bonding links adjacent spacing sheets in (GABA)2MA3Pb4I13 (MA=CH3NH3+), leading to the charges localized in the van der Waals gap, thereby constructing "charged‐bridge" for charge transfer through the spacing region. Additionally, the polarized GABA weakens dielectric confinement, decreasing the (GABA)2MA3Pb4I13 exciton binding energy as low as ≈73 meV. Benefiting from these merits, the resultant GABA‐based solar cell yields a champion power conversion efficiency (PCE) of 18.73 % with enhanced carrier transport properties. Furthermore, the unencapsulated device maintains 92.8 % of its initial PCE under continuous illumination after 1000 h and only lost 3 % of its initial PCE under 65 °C for 500 h. [ABSTRACT FROM AUTHOR]

Grain boundary cracks in flexible perovskite films can be repaired by filling with self‐repairing polymers during the preparation and wearable operation. However, the self‐repairing polymers are commonly active through external heating or humidification treatments, which cannot match with the human body's temperature tolerance of wearable devices. Herein, a body temperature‐responsive shape memory polyurethane (SMPU) is demonstrated to achieve the real‐time mechanical self‐repairing of grain boundary cracks (~37°C). Furthermore, the strong intermolecular interaction between SMPU and the uncoordinated Pb2+ and I−, can reduce the trap density in perovskite films. The blade‐coated device achieves a power conversion efficiency (PCE) of 21.33%, which is among the best reported flexible perovskite solar cells (PSCs; 0.10 cm2). Importantly, the device with SMPU can recover more than 80% of the PCE after 6000 cycles (bending radius: 8 mm). Finally, the flexible PSCs are used for wearable solar power supply of a smartphone, which show great potential for self‐repairing wearable electronics. [ABSTRACT FROM AUTHOR]

Defects at the interfaces of perovskite (PVK) thin films are the main factors responsible for instability and low photoelectric conversion efficiency (PCE) of PVK solar cells (PSCs). Here, a SnO2‐MXene composite electron transport layer (ETL) is used in PSCs to improve interfacial contact and passivate defects at the SnO2/perovskite interface. The introduced MXene regulates SnO2 dispersion and induces a vertical growth of PVK. The lattice matching of MXene and perovskite suppresses the concentration of interfacial stress, thereby obtaining a perovskite film with low defects. Compared with SnO2‐based device, the PCE of SnO2‐MXene‐based device is improved by 15 % and its short‐circuit current is up to 25.07 mA cm−2. Furthermore, unencapsulated device maintained about 90 % of its initial efficiency even after 500 h of storage at 30–40 % relative humidity in ambient air. The composite ETL strategy provides a route to engineer interfacial passivation between metal halide perovskites and ETLs. [ABSTRACT FROM AUTHOR]

Formamidinium (FA) based perovskites are considered as one of the most promising light‐absorbing perovskite materials owing to their narrower band gap and better thermal stability compared to conventional methylammonium‐based perovskites. Constant improvement by using various additives stimulates the potential application of these perovskites. Amine molecules with different structures have been widely used as typical additives in FA‐based perovskite solar cells, and decent performances have been achieved. Thus, a systematic review focusing on structural regulation and functional construction of amines in FA‐based perovskites is of significance. Herein, we analyze the construction mechanism of different structural amines on the functional perovskite crystals. The influence of amine molecules on specific perovskite properties including defect conditions, charge transfer, and moisture resistance are evaluated. Finally, we summarize the design rules of amine molecules for the application in high‐performance FA‐based perovskites and propose directions for the future development of additive molecules. [ABSTRACT FROM AUTHOR]

Although outstanding power conversion efficiency (PCE) has been achieved in flexible perovskite solar cells, unsatisfactory operational stability and toxicity caused by the moisture transmittance of polymer packaging are still the bottleneck challenges that limit their applications. Herein, inspired by the non‐selective permeability of inactivated cell membrane, the diphosphatidyl‐glycerol (Di‐g) is tactfully introduced as a self‐shield interface upon the perovskite layer. 96% of lead leakage is suppressed because the amphipathic Di‐g can simultaneously bind tightly to the divalent lead ion and afford an interfacial water‐resistance. More importantly, the gradient distribution of lattice residual stress perpendicular to the substrate are optimized. The resultant flexible devices achieve a PCE of 20.29% and 15.01% at effective areas of 1.01 and 21.82 cm2 respectively, yielding excellent environmental and mechanical stability. This strategy exhibits the feasibility of developing interfacial encapsulation to stabilize scalable PSCs with negligible lead leakage. [ABSTRACT FROM AUTHOR]

Perovskite (PVK) photodetectors (PDs) have emerged as highly‐efficient versatile optoelectrical devices due to their highly efficient and simple solution‐processable preparation method. Meanwhile, optical structures offer an efficient and facile strategy to improve the light‐harvesting performance of devices and introduce extra optical activity such as polarization sensitivity. Here, an efficient moiré perovskite photodetector with a stacked dual shallow grating structure is designed and fabricated, and sensitive digital polarization imaging is realized. The moiré PVK presents superior ability in light harvesting through the synergistic effects of feedback reflection, diffraction, and excitation of waveguide modes in the dual grating structure. Additionally, the highly crystalline PVK is fabricated through the imprint lithography process. Consequently, excellent device performance is achieved by taking advantage of highly‐efficient light‐harvesting and the good electrical properties of large grain PVK crystals. The responsivity (R) and detectivity (D*) of the moiré PVK PD are up to 15.62 A W and 5.58 × 1013 Jones, which are 6.7 and 7.8 times larger than that of the flat perovskite photodetector, respectively. The on/off ratio reaches 2.7 × 104. The nanograting array introduces good polarization sensitivity to the moiré PVK PD achieving a peak‐to‐valley ratio of 1.58. Excellent polarization images are obtained using a 576 pixel sensor array. [ABSTRACT FROM AUTHOR]

• The evolution of 2D perovskites based on multi-characteristic organic spacers is approached. • Impacts of the organic spacers on photophysical properties and film quality of 2D perovskites are discussed. • Several strategies to select and optimize the organic spacers for enhancing photovoltaic characteristics are proposed. [Display omitted] Two-dimensional (2D) perovskites have been attracting extensive attention due to their intrinsic stability compared with their three-dimensional (3D) counterparts. These materials are widely tailorable in composition, structure, and bandgap, and provide an intriguing playground for the solid-state chemistry and physics communities to uncover structure-property relationships. In the field of photovoltaic, the fabricated 2D perovskite solar cells (PSCs) have achieved high stability as well as sustainable breakthrough in power conversion efficiency (PCE). However, the PCE of 2D PSCs still lags far behind their 3D counterpart, which is attributed to the special physicochemical properties of organic ligands. This review focuses the 2D halide perovskites from a structural perspective, namely the Ruddlesden-Popper (RP) phases, Dion-Jacobson (DJ) phases, alternating cation in the interlayer space (ACI) phases and mixed organic ligands phases, which stems from the diversity and versatility of spacers. Then the impacts of the species, chemical compositions, and physical characteristics of spacers on 2D perovskites, especially on the structure, carrier behavior, and the specific properties of solar cells, were discussed. Finally, several strategies on the rational selection of novel spacers are elucidated, and an outlook toward high-performance of 2D PSCs is presented. [ABSTRACT FROM AUTHOR]

Releasing Nanocapsules for High-Throughput Printing of Stable Perovskite Solar Cells (Adv. Diffusion-controlled growth, high-throughput printing, perovskite nanocapsules, solar cells, stability Keywords: diffusion-controlled growth; high-throughput printing; perovskite nanocapsules; solar cells; stability EN diffusion-controlled growth high-throughput printing perovskite nanocapsules solar cells stability 1 1 1 09/13/21 20210909 NES 210909 B Perovskite Solar Cells b In article number 2101291, Meng Su, Yiwang Chen, Yanlin Song and co-workers design a perovskite nanocapsules ink to realize high-throughput printing of large-area efficient perovskite solar cells with excellent stability. [Extracted from the article]

[Display omitted] • CsPbBr 3 perovskite film is deposited by vacuum co-evaporation. • Effective charge transport and reduced trap-state density is realized in device. • The champion power conversion efficiency of 9.43% is recorded. • Remaining at 96% of initial performance after storing under 40% humidity for 480 h. High power conversion efficiency (PCE) and good long-term stability are everlasting pursuit for perovskite solar cells. We present here CsPbBr 3 perovskite film deposited by vacuum co-evaporation of CsBr and PbBr 2. By optimizing evaporation rate ratio of the two precursor and annealing temperature, perovskite films with large grain and high crystallinity are obtained. Furthermore, by regulating spinning speed of TiO 2 precursor solution and thickness of CsPbBr 3 film, a best PCE of 9.43% is recorded under 100 mW cm−2 illumination, providing a significant enhancement in contrast with 6.26% of device based on spin-coating method. Additionally, the PCE of resulting perovskite solar cell without encapsulation remains at 96% of initial value after storing for 480 h under humidity of 40% in air. Our findings in this work deliver an effective strategy to fabricate high-performance inorganic perovskite solar cells. [ABSTRACT FROM AUTHOR]