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The device performance of deep‐blue perovskite light‐emitting diodes (PeLEDs) is primarily constrained by low external quantum efficiency (EQE) especially poor operational stability. Herein, we develop a facile strategy to improve deep‐blue emission through rational interface engineering. We innovatively reported the novel electron transport material, 4,6‐Tris(4‐(diphenylphosphoryl)phenyl)‐1,3,5‐triazine (P‐POT2T), and utilized a sequential wet‐dry deposition method to form the homogenic gradient interface between electron transport layer (ETL) and perovskite surface. Unlike previous reports that achieved carrier injection balance by inserting new interlayers, our strategy not only passivated uncoordinated Pb2+ in the perovskite via P=O functional groups but also reduced interfacial carrier recombination without introducing new interfaces. Additionally, this strategy enhanced the interface contact between the perovskite and ETL, significantly boosting device stability. Consequently, the fabricated deep‐blue PeLEDs delivered an EQE exceeding 5 % (@ 460 nm) with an exceptional halftime extended to 31.3 minutes. This straightforward approach offers a new strategy to realize highly efficient especially stable PeLEDs. [ABSTRACT FROM AUTHOR]

Traditional polyamide elastomer synthesis via polycondensation of diamines and dicarboxylic acids involves high energy use and by‐product mass loss. Here, we present a novel method using thiol‐Michael addition click chemistry to produce these elastomers under mild conditions, marking the first use of this strategy. The polymerization involves coupling bis‐acrylamide (BAA) with 3,6‐dioxa‐1,8‐octanedithiol (DODT), catalyzed by 1,5‐diazabicyclo[4.3.0]non‐5‐ene (DBN). BAA is synthesized from polyetheramine and acryloyl chloride, creating a compound with amide groups and carbon double bonds at chain ends. These double bonds' electron‐withdrawing effect facilitates the click reaction efficiently, avoiding high energy and mass loss. The resulting polymers have a molecular weight of approximately 10,000 g/mol, verified by 1H NMR and FTIR spectroscopy, which show amide group presence. SAXS and AFM confirm nanophase separation of these groups. Tensile strength ranges from 0.235 to 0.542 MPa, decreasing with lower polyetheramine content but still showing notable elasticity. This method's low energy use, no mass loss, and good mechanical properties make it promising for developing high‐performance polyamide plastics and elastomers, appealing to researchers in both academia and industry. Highlights: High elasticity, softness, and high tensile polyamide elastomer.Thiol‐Michael addition click reaction conforms to atomic economy.Long molecular chain contains extraordinary evolution of hydrogen bonding. [ABSTRACT FROM AUTHOR]

Blue perovskite light‐emitting diodes (PeLEDs) are crucial avenues for achieving full‐color displays and lighting based on perovskite materials. However, the relatively low external quantum efficiency (EQE) has hindered their progression towards commercial applications. Quasi‐two‐dimensional (quasi‐2D) perovskites stand out as promising candidates for blue PeLEDs, with optimized control over low‐dimensional phases contributing to enhanced radiative properties of excitons. Herein, the impact of organic molecular dopants on the crystallization of various n‐phase structures in quasi‐2D perovskite films. The results reveal that the highly reactive bis(4‐(trifluoromethyl)phenyl)phosphine oxide (BTF‐PPO) molecule could effectively restrain the formation of organic spacer cation‐ordered layered perovskite phases through chemical reactions, simultaneously passivate those uncoordinated Pb2+ defects. Consequently, the prepared PeLEDs exhibited a maximum EQE of 16.6 % (@ 490 nm). The finding provides a new route to design dopant molecules for phase modulation in quasi‐2D PeLEDs. [ABSTRACT FROM AUTHOR]

A simple and efficient salicylaldehyde‐promoted cobalt‐catalyzed protocol for the C−H alkoxylation of aromatic amides by employing primary alcohols as the coupling partner has been developed. This method utilizes a 8‐aminoquinoline moiety as the directing group and successfully achieves the ortho−C−H alkoxylation in moderate to good yields under mild conditions. This protocol features excellent functional tolerance and broad substrate scope including natural products. In addition, the directing group could be easily removed as well. [ABSTRACT FROM AUTHOR]

Deep‐blue perovskite light‐emitting diodes (PeLEDs) based on quasi‐two‐dimensional (quasi‐2D) systems exist heightened sensitivity to the domain distribution. The top‐down crystallization mode will lead to a vertical gradient distribution of quantum well (QW) structure, which is unfavorable for deep‐blue emission. Herein, a thermal gradient annealing treatment is proposed to address the polydispersity issue of vertical QWs in quasi‐2D perovskites. The formation of large‐n domains at the upper interface of the perovskite film can be effectively inhibited by introducing a low‐temperature source in the annealing process. Combined with the utilization of NaBr to inhibit the undesirable n=1 domain, a vertically concentrated QW structure is ultimately attained. As a result, the fabricated device delivers a narrow and stable deep‐blue emission at 458 nm with an impressive external quantum efficiency (EQE) of 5.82 %. Green and sky‐blue PeLEDs with remarkable EQE of 21.83 % and 17.51 % are also successfully achieved, respectively, by using the same strategy. The findings provide a universal strategy across the entire quasi‐2D perovskites, paving the way for future practical application of PeLEDs. [ABSTRACT FROM AUTHOR]

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