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The roles of organic ammonium salts (OASs) which are widely used for the surface treatment of the perovskite film, including formation of 2D perovskites, direct surface passiviation, and other effects, have been reviewed. The influencing factors for these roles of OASs are also discussed, which are important for improved efficiency and stability of perovskite solar cells. More information can be found in the Review article by X. Guo and co‐workers. (DOI: 10.1002/chem.202203001) [ABSTRACT FROM AUTHOR]

Yellow‐phase formamidinium lead iodide (δ‐FAPbI3) as a degradation product of black perovskite phase is usually unwelcome in perovskite solar cells (PSCs). However, it also shows high potential in passivating defects and protecting perovskite films from moisture intrusion due to its water‐stable nature. Herein, the utilization of δ‐FAPbI3 to construct a yellow/black heterophase bilayer is reported, in which the perovskite layer is shielded by in situ formed δ‐FAPbI3 species on the surface, for PSCs with enhanced efficiency and stability. It is found that the δ‐FAPbI3 layer with a broader bandgap than the black‐phase perovskite can efficiently suppress the charge recombination at the interface, offering a high PSC efficiency of 23.10%. More importantly, the δ‐FAPbI3‐modified devices exhibit preferable stability against various external stresses to that of the control ones. Compared to those using the disliked δ‐FAPbI3 in the literature, the strategy, which maximizes its merits in reducing the interfacial charge recombination and stabilizing the perovskite structure, is more simple yet effective to realize highly efficient and stable PSCs. [ABSTRACT FROM AUTHOR]

Organic ammonium salts (OASs) have been widely used to passivate perovskite defects. The passivation mechanism is usually attributed to coordination of OASs with unpaired lead or halide ions, yet ignoring their interaction with excess PbI2 on the perovskite film. Herein, we demonstrate that OASs not only passivate defects by themselves, but also redistribute excess aggregated PbI2 into a discontinuous layer, augmenting its passivation effect. Moreover, alkyl OAS is more powerful to disperse PbI2 than a F‐containing one, leading to better passivation and device efficiency because F atoms restrict the intercalation of OAS into PbI2 layers. Inspired by this mechanism, exfoliated PbI2 nanosheets are adopted to provide better dispersity of PbI2, further boosting the efficiency to 23.14 %. Our finding offers a distinctive understanding of the role of OASs in reducing perovskite defects, and a route to choosing an OAS passivator by considering substitution effects rather than by trial and error. [ABSTRACT FROM AUTHOR]

All‐inorganic lead halide perovskites are promising candidates for optoelectronic applications. However, fundamental questions remain over the component interaction in the perovskite precursor solution due to the limitation of the most commonly used solvents of N,N‐dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Here, we report an interaction tailoring strategy for all‐inorganic CsPbI3−xBrx perovskites by involving the ionic liquid solvent methylammonium acetate (MAAc). C=O shows strong interaction with lead (Pb2+) and N−H⋅⋅⋅I hydrogen bond formation is observed. The interactions stabilize the perovskite precursor solution and allow production of the high‐quality perovskite films by retarding the crystallization. Without the necessity for antisolvent treatment, the one‐step air‐processing approach delivers photovoltaic cells regardless of humidity, with a high efficiency of 17.10 % along with long operation stability over 1500 h under continuous light illumination. [ABSTRACT FROM AUTHOR]

Keywords: defect passivation; organic ammonium salts; perovskite solar cells; surface treatment; two-dimensional perovskites EN defect passivation organic ammonium salts perovskite solar cells surface treatment two-dimensional perovskites 1 1 1 02/21/23 20230216 NES 230216 The roles of organic ammonium salts (OASs) which are widely used for the surface treatment of the perovskite film, including formation of 2D perovskites, direct surface passiviation, and other effects, have been reviewed. Defect passivation, organic ammonium salts, perovskite solar cells, surface treatment, two-dimensional perovskites The influencing factors for these roles of OASs are also discussed, which are important for improved efficiency and stability of perovskite solar cells. [Extracted from the article]

This study presents a novel robust model predictive control (MPC) method for constrained non‐linear systems with control constraints and external disturbances. The control signal is obtained by optimising an objective function consisting of two terms: an integral non‐squared stage cost and a non‐squared terminal cost. The terminal weighting matrix is designed appropriately such that: (i) the terminal cost serves as a control Lyapunov function; and (ii) the resultant finite horizon cost can be treated as a quasi‐infinite horizon cost. Provided that the Jacobian linearisation of the system to be controlled is stabilisable and the optimisation is initially feasible, sufficient conditions ensuring the recursive feasibility of the optimisation and the robust stability of the closed‐loop system are established. It is shown that the conditions rely on an appropriate design of the sampling interval with respect to a certain given disturbance level. The effectiveness of the proposed method is illustrated through a numerical example. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the structure and thermal property of P(AN-MMA)/SiO2 hybrid material, and the phase and ionic conductivity of poly(acrylo-nitrile-methyl methacrylate) (P(AN-MMA)/silicon dioxide (SiO2) doped LiClO4 hybrid solid electrolytes. In this study, the P(AN-MMA)/SiO2 hybrid solid electrolytes were prepared with tetraethoxysilane (TEOS), acrylonitrile (AN), and methyl methacrylate (MMA) as starting material.