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We introduce a "solution‐processing‐transformation" strategy, deploying solvent vapor as scaffolds, to fabricate high‐quality hydrogen‐bonded organic framework (HOF) membranes. This strategy can overcome the mismatch in processing conditions and crystal growth thermodynamics faced during the facile solution processing of the membrane. The procedure includes the vapor‐trigged in situ transformation of dense amorphous supramolecules to crystalline HOF‐16, with HOF‐11 as the transient state. The mechanism involves a vapor‐activated dissolution‐precipitation equilibrium shifting and hydrogen bonding‐guided molecule rearrangement, elucidated through combined experimental and theoretical analysis. Upon removal of the molecular scaffolds, the resulting HOF‐16 membranes showcase significant improvement in hydrogen separation performance over their amorphous counterparts and previously reported HOF membranes. The method's broad applicability is evidenced by successfully extending it to other substrates and HOF structures. This study provides a fundamental understanding of guest‐induced ordered supramolecular assembly and paves the way for the advanced manufacture of high‐performance HOF membranes for gas separation processes. [ABSTRACT FROM AUTHOR]

The article titled "Rücktitelbild: In Situ Transformation of an Amorphous Supramolecular Coating to a Hydrogen-Bonded Organic Framework Membrane to Trigger Selective Gas Permeation" explores a strategy for creating high-quality hydrogen-bonded organic framework (HOF) membranes for gas separation. The researchers, Zixi Kang, Daofeng Sun, and others, use methanol scaffolds to achieve this. The methanol scaffolds contribute to the membranes' improved hydrogen separation performance through vapor-activated monomer dissolution-precipitation equilibrium shifts and hydrogen bonding-guided monomer rearrangement. [Extracted from the article]

The perovskite CH3NH3PbI3 excited‐state lifetimes exhibit conflicting experimental results under humid environments. Using ab initio nonadiabatic (NA) molecular dynamics, we demonstrate that the interplay between lead vacancy and water can rationalize the puzzle. The lead vacancy reduces NA coupling by localizing holes, slowing electron–hole recombination. By creating a deep electron trap state, the coexistence of a neutral lead vacancy and water molecules enhances NA coupling, accelerating charge recombination by a factor of over 3. By eliminating the mid‐gap state by accepting two photoexcited electrons, the negatively charged lead vacancy interacting with water molecules increases the carrier lifetime over 2 times longer than in the pristine system. The simulations rationalize the positive and negative effects of water on the solar cell performance exposure to humidity. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have emerged as a new generation of X‐ray detector materials. However, large‐sized MAPbI3 single crystals (SCs) still exhibit lower performance than MAPbBr3 SCs in X‐ray detection. DFT (density functional theory) simulations suggest the problem could be overcome by alloying large‐sized cations at the A site. The alloyed process could notably decrease the electron–phonon coupling strength and increase the material defect formation energy. Accordingly, centimeter‐sized alloyed DMAMAPbI3 (DMA=dimethylammonium) and GAMAPbI3 (GA=guanidinium) SCs are obtained. Electrical characterizations confirm the GAMAPbI3 SCs display improved charge collection efficiency. It also exhibits a remarkable reduction of dark current, an important figure of merit for X‐ray detectors. With a judiciously designed device architecture, the overall detector performance confirms GAMAPbI3 SCs as one of the most sensitive perovskite X‐ray detectors to date. [ABSTRACT FROM AUTHOR]