Research on chemically stable inorganic perovskites has achieved rapid progress in terms of high efficiency exceeding 19% and high thermal stabilities, making it one of the most promising candidates for thermodynamically stable and high‐efficiency perovskite solar cells. Among those inorganic perovskites, CsPbI3 with good chemical components stability possesses the suitable bandgap (≈1.7 eV) for single‐junction and tandem solar cells. Comparing to the anisotropic organic cations, the isotropic cesium cation without hydrogen bond and cation orientation renders CsPbI3 exhibit unique optoelectronic properties. However, the unideal tolerance factor of CsPbI3 induces the challenges of different crystal phase competition and room temperature phase stability. Herein, the latest important developments regarding understanding of the crystal structure and phase of CsPbI3 perovskite are presented. The development of various solution chemistry approaches for depositing high‐quality phase‐pure CsPbI3 perovskite is summarized. Furthermore, some important phase stabilization strategies for black phase CsPbI3 are discussed. The latest experimental and theoretical studies on the fundamental physical properties of photoactive phase CsPbI3 have deepened the understanding of inorganic perovskites. The future development and research directions toward achieving highly stable CsPbI3 materials will further advance inorganic perovskite for highly stable and efficient photovoltaics.

The in situ formation of reduced dimensional perovskite layer via post‐synthesis ion exchange has been an effective way of passivating organic‐inorganic hybrid perovskites. In contrast, cesium ions in Cs‐based inorganic perovskite with strong ionic binding energy cannot exchange with those well‐known organic cations to form reduced dimensional perovskite. Herein, we demonstrate that tetrabutylammonium (TBA+) cation can intercalate into CsPbI3 to effectively substitute the Cs cation and to form one‐dimensional (1D) TBAPbI3 layer in the post‐synthesis TBAI treatment. Such TBA cation intercalation leads to in situ formation of TBAPbI3 protective layer to heal defects at the surface of inorganic CsPbI3 perovskite. The TBAPbI3‐CsPbI3 perovskite exhibited enhanced stability and lower defect density, and the corresponding perovskite solar cell devices achieved an improved efficiency up to 18.32 % compared to 15.85 % of the control one.

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In the past few years, inorganic CsPbI 3 perovskite has made significant progress on improving both phase stability and optoelectrical performance owing to tremendous research efforts and in-depth understanding, especially on the crystal phases of inorganic CsPbI 3 perovskite and the development of different passivation approaches. [12][13][14][15][16] Recently, more and more investigations on the deep-level physical mechanisms of inorganic perovskites have promoted their efficiency development. [17][18][19] Based on the characterization by single crystal X-ray diffraction and X-ray pair distribution function measurements, Cava and co-workers confirmed that low effective coordination among Cs + and [PbI 6 ] 4− octahedra should be responsible for the instability of perovskite-phase CsPbI 3 . [19,20] Liang et al. further revealed the existence of many unavoidable defects in CsPbI 3 such as Cs + vacancy, undercoordinated Pb 2+ , etc. [21] These defects can weaken the interactions between Cs + and [PbI 6 ] 4− octahedra, which decreases the energy difference between the black and yellow phases. [22] It is therefore important to solve the issue of defect-triggered phase degradation in inorganic CsPbI 3 perovskite. Currently, defect passivation is an effective approach to improve the performance of inorganic CsPbI 3 perovskites including phase stability and optoelectrical performance. Many passivation agents including phenyltrimethylammonium chloride, octylammonium iodides, ureaammonium thiocyanate, etc., have been developed to stabilize and passivate inorganic perovskites. [23][24][25] Crystal secondary growth has been widely utilized in hybrid perovskites to reduce the defects as well as to enhance the stability and optoelectrical performance. The most popular crystal secondary growth approach is the postsynthetic halide salt treatment, especially using the solution of Br salt for treatment. [26,27] In OIHPs, such as MAPbI 3 , the crystal secondary growth occurs easily during a postsynthesis ammonium halide solution treatment even without thermal annealing. However, such crystal secondary growth strategy is difficult to be implemented for inorganic perovskites, which could be ascribed to the strong ionic bonds in inorganic perovskite. There are few works reporting the crystal secondary growth of inorganic CsPbI 3 perovskite. Herein, we demonstrate a solidstate-reaction-induced crystal secondary growth of inorganic perovskite to realize the defect compensation in inorganic CsPbI 3 perovskite and improve the optoelectrical performance Defect-triggered phase degradation is generally considered as the main issue that causes phase instability and limited device performance for CsPbI 3 inorganic perovskites. Here, a defect compensation in CsPbI 3 perovskite through crystal secondary growth of inorganic perovskites is demonstrated, and highly efficient inorganic photovoltaics are realized. This secondary growth is achieved by a solid-state reaction between a bromine salt and defective CsPbI 3 perovskite. Upon solid-state rea...

Glycosylation is a topic of intense current interest in the development of biopharmaceuticals because it is related to drug safety and efficacy. This work describes results of an interlaboratory study on the glycosylation of the Primary Sample (PS) of NISTmAb, a monoclonal antibody reference material. Seventy-six laboratories from industry, university, research, government, and hospital sectors in Europe, North America, Asia, and Australia submitted a total of 103 reports on glycan distributions. The principal objective of this study was to report and compare results for the full range of analytical methods presently used in the glycosylation analysis of mAbs. Therefore, participation was unrestricted, with laboratories choosing their own measurement techniques. Protein glycosylation was determined in various ways, including at the level of intact mAb, protein fragments, glycopeptides, or released glycans, using a wide variety of methods for derivatization, separation, identification, and quantification. Consequently, the diversity of results was enormous, with the number of glycan compositions identified by each laboratory ranging from 4 to 48. In total, one hundred sixteen glycan compositions were reported, of which 57 compositions could be assigned consensus abundance values. These consensus medians provide community-derived values for NISTmAb PS. Agreement with the consensus medians did not depend on the specific method or laboratory type. The study provides a view of the current state-of-the-art for biologic glycosylation measurement and suggests a clear need for harmonization of glycosylation analysis methods.

Formamidinium lead iodide (FAPbI3)‐based perovskites have become one of the most promising candidate materials for high efficiency and thermally stable perovskite solar cells due to their outstanding optoelectrical properties and high thermal stability. However, the phase degradation of black FAPbI3 perovskite phase to yellow nonperovskite phase at ambient conditions restricts the long‐term stability of FAPbI3 perovskite solar cells. Such phase transition can be affected by various conditions especially under humidity and thermal stress. To address the phase instability issue, tremendous research efforts have been devoted to crystallizing high‐quality black phase and refraining the photoinactive δ‐phase formation. Herein, first, these research efforts are summarized for the deposition of FAPbI3 perovskite film and the stabilization of pure α‐FAPbI3 perovskite, then the FAPbI3 structural features and phase transformation behavior are discussed. The corresponding strategies for maintaining black phase and enhancing optical properties of FAPbI3 perovskite is also concluded. Second, the latest progress and achievement of stabilizing black‐phase FAPbI3 are discussed through various methods including additives, doping, and alloying, interfacial engineering, etc. Finally, the future research directions and strategies to achieve high efficiency and stable FAPbI3‐based perovskite solar cells are described.

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To study the biological role of the chemokine ligands CCL19 and CCL21, we generated transgenic mice expressing either gene in oligodendrocytes of the CNS. While all transgenic mice expressing CCL19 in the CNS developed normally, most (18 of 26) of the CCL21 founder mice developed a neurological disease that was characterized by loss of landing reflex, tremor, and ataxia. These neurological signs were observed as early as postnatal day 9 and were associated with weight loss and death during the first 4 wk of life. Microscopic examination of the brain and spinal cord of CCL21 transgenic mice revealed scattered leukocytic infiltrates that consisted primarily of neutrophils and eosinophils. Additional findings included hypomyelination, spongiform myelinopathy with evidence of myelin breakdown, and reactive gliosis. Thus, ectopic expression of the CC chemokine CCL21, but not CCL19, induced a significant inflammatory response in the CNS. However, neither chemokine was sufficient to recruit lymphocytes into the CNS. These observations are in striking contrast to the reported activities of these molecules in vitro and may indicate specific requirements for their biological activity in vivo.