Lijun Zhang

Tin halide perovskites are promising lead‐free emitters, but their soft and chemically labile lattices make interfacial stabilization inherently difficult. In CsSnBr ₃ , fluctuating surface coordination and structural instability drive defect formation, non‐radiative recombination and rapid device degradation. Current molecular passivation strategies rely largely on static binding motifs, including single‐site coordination and rigid multidentate anchoring, which are poorly matched to a dynamically evolving perovskite surface. Here, we show that 2‐furanethanaminium thiocyanate (FEASCN), an ionically linked multidentate passivator that combines strong intra‐ion‐pair correlation with bounded configurational compliance, enables adaptive stabilization of CsSnBr ₃ emitters. FEASCN undergoes limited configurational relaxation in response to lattice vibrations and fluctuating surface coordination, maintaining persistent surface matching rather than detaching from the interface. This adaptive coordination suppresses defects, stabilizes the lattice, improves film quality and promotes more balanced carrier injection. CsSnBr ₃ light‐emitting diodes (LEDs) based on this strategy achieve a peak luminance of 1344 cd m ⁻² , a record external quantum efficiency of 2.64% and a sixfold improvement in operational stability. These findings establish dynamic surface matching as a route to efficient and stable lead‐free perovskite electroluminescence.

The bulk photovoltaic effect (BPVE) in polar crystals offers a promising way to surpass the energy-conversion limits of conventional p–n junction devices. In layered materials, BPVE is typically dominated by an out-of-plane component. However, strong in-plane performance is essential for planar photovoltaics, requiring innovative strategies to overcome fundamental material constraints. In this study, an innovative pressure-induced emergence of in-plane BPVE is demonstrated in the planar-nonpolar layered bulk semiconductor γ-type indium selenide. External pressure distorts the lattice and breaks the intrinsic threefold rotational symmetry, triggering in-plane photovoltaic responses that are otherwise symmetry-forbidden at ambient pressure. Furthermore, the in-plane BPVE shows a distinctive crystallographic orientation dependence: the photocurrent is significantly higher along the armchair direction than along the zigzag direction, with a large anisotropy ratio of up to 280 observed at 0.16 GPa. Experimental characterization and first-principles calculations reveal that pressure lifts the symmetry-protected planar nonpolarity, reconstructing the electronic structure and activating a sizable in-plane shift-current response that is forbidden at ambient pressure. More broadly, this work establishes symmetry engineering through pressure as a general strategy for achieving large in-plane bulk photovoltaic responses in layered systems, without relying on material nanostructuring or interfacial design.

While highly ordered self‐assembled monolayers (SAMs) are critically important for inverted perovskite solar cells (i‐PSCs), precise control over molecular orientation remains a persistent challenge, hindering the concurrent achievement of high efficiency and long‐term stability. To address this issue, we unveil that the molecular orientation of SAMs based on bis‐carbazole phosphonates is governed by their conformational structures, which can be finely modulated through tailored carbazole–carbazole binding geometries. These structurally ordered layers provide a robust platform for deliberate energy level alignment and enhanced charge transport selectivity, enabling a certified power conversion efficiency of 27.2%, an impressive value that ranks among the highest reported for i‐PSCs. Moreover, owing to the robust anchoring capability afforded by the bis‐phosphonate design, the devices exhibit extended operational stability—retaining 96% of their initial efficiency after 1400 h under one‐sun illumination and maximum power point tracking, and show excellent compatibility with scalable fabrication in ambient air. This work thus establishes a powerful chemical strategy for tailoring molecular orientation, providing a promising molecular design paradigm for advancing perovskite photovoltaics.

While highly ordered self‐assembled monolayers (SAMs) are critically important for inverted perovskite solar cells (i‐PSCs), precise control over molecular orientation remains a persistent challenge, hindering the concurrent achievement of high efficiency and long‐term stability. To address this issue, we unveil that the molecular orientation of SAMs based on bis‐carbazole phosphonates is governed by their conformational structures, which can be finely modulated through tailored carbazole–carbazole binding geometries. These structurally ordered layers provide a robust platform for deliberate energy level alignment and enhanced charge transport selectivity, enabling a certified power conversion efficiency of 27.2%, an impressive value that ranks among the highest reported for i‐PSCs. Moreover, owing to the robust anchoring capability afforded by the bis‐phosphonate design, the devices exhibit extended operational stability—retaining 96% of their initial efficiency after 1400 h under one‐sun illumination and maximum power point tracking, and show excellent compatibility with scalable fabrication in ambient air. This work thus establishes a powerful chemical strategy for tailoring molecular orientation, providing a promising molecular design paradigm for advancing perovskite photovoltaics.

Inverted perovskite solar cells (PSCs) possess great potential for improving efficiency and operating stability, but parasitic charge recombination at the interfaces still limits their performance. As additives and surface treatment agents, ammonium ligands have been reported to form either two/three‐dimensional (2D/3D) heterojunctions or passivation layers. In this work, we first conduct a comprehensive, large language model (LLM)‐enabled literature mining to systematically enumerate ligand molecules reported over the past decade, through which we identify a pronounced knowledge gap concerning thiazole‐based ligands. Then, in a comparative case study, perovskite films are treated with two thiazole‐ and thiophen‐based ligands, which are small rigid aromatic heterocycles with similar molecular conformation. Thiophen‐2‐ylmethanamine hydrochloride (TPMA) induces 2D phase formation within 3D perovskite films. In comparison, 1,3‐thiazol‐2‐ylmethanamine hydrochloride (TMA), with enhanced charge‐transfer interactions associated with the S ions on the aromatic rings, demonstrates a stronger defect passivation capability. Overall, the TMA‐based counterpart exhibits lower defect density, extended carrier lifetime, and a more favorable band offset. With the thiazole‐based ligand, the resulting inverted PSC achieves an efficiency of 26.81% (certified 26.43%) and retains 96.4% of its initial performance after 1000 h tracking under continuous illumination at the maximum power point.

Near-zero thermal expansion (NZTE) materials are essential for emerging precision technologies, such as optical instruments and aerospace components. However, existing materials with robust performance over a broad temperature range are limited, especially if functional properties in addition to NZTE are sought. We report a data-driven materials design investigation and find that the zinc-blende structure is an excellent platform for obtaining NZTE and elucidating underlying crystal-chemical principles. Based on these, we introduced vacancy engineering and stuffed-atom incorporation, yielding a series of cubic quaternary chalcogenides AM3M′X4, where linkage ion vibrations are systematically modulated. We found that NaAg3TiS4, NaAg3TiSe4, and RbAg3TiSe4 are promising NZTE candidates with coefficients of thermal expansion below 2 × 10–6 K–1 over extended temperature windows (300–600 K). These are semiconducting materials distinct from low-thermal-expansion oxides. We explain the NZTE via the synergistic contributions of lattice softening, rigid-unit tilting, and linkage-ion transverse vibrations to the negative Grüneisen parameters. The stuffing of the zinc blende-based lattice provides a chemical way of tuning the linkage-ion transverse modes, thus controlling the thermal expansion in order to obtain NZTE.

Solar-driven electrochemical CO ₂ reduction to multicarbon (C ₂₊ ) products presents a promising avenue for artificial photosynthesis, yet remains constrained by high overpotentials and limited conversion efficiency. Here, we developed an alkaline environment-modulated prereduction strategy that capitalizes on the divergent thermodynamic stabilities of precursors, enabling the precise synthesis of iodine-doped copper nanotopologies (Cu-I NTs). Featuring tunable under-coordination defects and stabilized high-energy adsorption sites, the Cu-I NTs achieve an onset potential of only −0.37 V versus the reversible hydrogen electrode for C ₂₊ formation. Operando Raman measurement and density functional theory calculation reveal that the tailored surface topologies favor Cu-CO rotation adsorption, enabling dynamic reorientation from bridge- to atop-binding configurations, which collectively lowers the barrier for CO-CO coupling. Impressively, powering the electrolyzer by a perovskite/silicon tandem together with a single-junction silicon photovoltaic device, the system delivers a photocurrent of 12.34 mA cm ⁻² at 2.17 V under standard AM 1.5 illumination, achieving a solar-to-C ₂₊ conversion efficiency of 8.64%.

Simultaneous precise control over luminescence and chiroptical activity in a single crystalline platform is a long‐standing goal for chiral optoelectronics. 1D chiral organic–inorganic lead halides (OILHs) are ideal candidates due to their diverse self‐trapped excitons (STEs) emissions and circular dichroism (CD) responses. However, the microscopic origins of STE diversity and CD inversion remain controversial, limiting targeted optimization. This work employs high pressure to trigger highly efficient dual STE emission with CD inversion in 1D chiral OILH R ‐C ₅ H ₁₄ N ₂ PbCl ₄ ·H ₂ O, which is based on significantly strengthened octahedral coupling. Excited‐state configuration coordinate calculations and transient spectroscopy reveal that this strengthened octahedral coupling intensifies octahedral distortion and transient structural deformation, which facilitate the formation of dual polaron‐pair STEs while deepening the STE trapping depth and elevating the quenching barrier. This confirms that polaron‐pair STEs can be converted from nonradiative into efficient radiative recombination centers, resolving the controversy over polaron‐pair STEs’ luminescence efficiency. Furthermore, CD calculations based on the same chiral configuration demonstrate that enhanced octahedral coupling and distortion alter the predominance of two groups of transitions with opposite rotational strengths, inducing the CD inversion even without changing the intrinsic chirality. These findings provide a blueprint for designing OILHs with efficient luminescence and programmable chiroptical properties.